Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: dwdallam on March 10, 2005, 08:04:03 pm
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I've noticed some of those things you mention. However, if you can use the F828, and play with getting shallow DOF, you'll see it's difficult, as you state, for physical limitations of the camera.
But let's say you have a large subject, like a 60 foot fishing boat, and you want to get most of the boat in teh picture, either 90 degrees or 30, or wahtever the angle, and you want to have a shallow DOF in marina--such as the pictures in the link I posted. Could you do that with a different camera? If so, can you post a picture that accomplishes that?
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Didger, as your next photshop task you may want to play with the lens blur filter rather than gaussian blur to achive an OOF effect. You can use a gradient in the layer mask to vary the blur effect progressively which can give some nice effects, though takes a bit of practice to get the right look.
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Before anyone commits mathematical obscenities, DPR lists the F828 lens as a 28 - 200 mm eq. and 7.1 - 51 is printed on the front of the lens.
(And I've long been looking for a piece of software that would let one select areas of an image and assign different amounts of focus/blur as desired.)
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2) Howard, I think your estimate on teh true mm size of the F828 is a little off. I think I read where it is actually 28 to 80mm effective?
Howard is pretty close. "35mm equivalent" is meaningless in the contect of DOF, the actual focal length is what's important. Since the sensor is much smaller tha the 24x36mm of a frame of film, the focal lengths are similarly smaller. If the 828's sensor is 1/5 the size of 35mm film, then the focal length of the lens would be 1/5 of the "35mm equivalent" so a 28-80 "equivalent" would actually be 5.6-16mm. The size difference isn't exactly 5:1, but somewhere in that vicinity.
Okay I see what you mean. That makes sense to me. As far as true zoom goes, what is the focdal lenght of the F828, given the zoom capability alone? It says 28-200, but I know that's fluff.
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DOF Calculator (http://www.visual-vacations.com/Photography/dof_calculation.htm)
The default sensor values are for the Canon 1Ds; for the 828, use 2448 pixels and 6.6mm. To compare DOF between the 1Ds and the 828, save a copy of the spreadsheet with the 828 sensor settings. Then set up a scenario with equal subject distances and divide the focal length of the 1Ds by 3.636 to get the equivalent vertical FOV for the 828.
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It just gives you less depth of field - the size of the subject is inconsequential.
To understand DOF it's helpful to do some outside reading. Here's a link which might help....
Lin
http://members.aol.com/Photoinfo/dof.html (http://members.aol.com/Photoinfo/dof.html)
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If you want to contact a professional photographer that specialises in boats you may wish to try the following photographer - Nicolas Claris. He often hangs out on Rob Galbraiths website.
Claris Organisation (http://www.claris.fr/)
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In a recent thread, we were discussing shallow DOF and the SonyF828 (and other small sensor cameras in relation to large). I'd like to see what others who own this camera can do to get the best shallow DOF possible, as a comparison to myself. Then I can see if I'm getting all I can out of the camera.
The subject should be large, as with the boats I have here:
http://www.idlethoughtsandchaos.com/photo/ (http://www.idlethoughtsandchaos.com/photo/)
and the background should be blurred as much as possible. I'd like to see how the DSLRs do that job, along with 35mm film. Then I'll have a good idea where these cameras fall in relation to each other. I'd also like to see some portrait pictures and shallow DOF also using the above cameras. If you could also cite the apeture, speed, and ISO, that would be great too.
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It's not a boat, but it is an example of shallow DOF achievable with the full-frame Canon 1Ds:
(http://galleries.visual-vacations.com/images/2004-12-11-0168.jpg)
The girls are not quite 3 years old, the palm tree in the right background is about 2 feet behind them, and the palm tree in the left background is about 10 feet behind them. Is this the kind of shallow DOF you're looking for?
Canon 1Ds, EF 24-70/2.8L @ 55mm, f/3.2, 1/2000, ISO 200
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All this stuff about problems getting LESS DOF with small sensor cameras is interesting and makes sense, though not having a small sensor camera nor frequent occasions to want shallow DOF, I haven't experienced these problems, though once in a while I've decided after the fact to defocus some carefully selected area in an image with Gaussian blur. Don't forget how powerful Photoshop can be for faking shallow DOF for many situations. Something like Jonathan's little girls would be easy because that background would be easy to select and the same amount of blur for the entire background would be OK.
Something like a big boat at an angle to the viewer would be harder because the boat would need to get blurry gradually as it recedes. With Quick Mask you can create a very complex selection that's feathers at the edges to any degree in any way you want in different areas and directions. This is not so easy and certainly not fast, but almost anything could be done with appropriate selections and the right blur formula. Not something I've ever had occasion to do, but I've done super complex selections with variably fading edges like that for other purposes and you could certainly do complex blur patterns of any sort you want for simulating shallow DOF.
Now the pity is that there's no way to fake MORE DOF than what you shot. You could do multiple exposures, however, and there's even some shareware to help with that. This system was developed by microphotographers, who are always burdened with extremely shallow DOF.
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DiaAzul's last image (stack of hay bales) is interesting. But look at the ground just in front of the stack. It looks to me that the ground looks "out of focus" but the hay just above there is in focus.
Howard, perhaps one day you will learn to read peoples posts properly and utilise the grey matter that sits between your ears. I know that the picture is not perfect and that the effect has some imperfections, however, it was posted to give an indication that Photoshop does have tools to artificially create a shallow DOF effect. If I had more time then it would be possible to achieve a more natural look by modifying the gradient mask so that their is not a disconnect in the focus around the haystack. This is not difficult to do, just takes time.
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It's not a boat, but it is an example of shallow DOF achievable with the full-frame Canon 1Ds:
(http://galleries.visual-vacations.com/images/2004-12-11-0168.jpg)
The girls are not quite 3 years old, the palm tree in the right background is about 2 feet behind them, and the palm tree in the left background is about 10 feet behind them. Is this the kind of shallow DOF you're looking for?
Canon 1Ds, EF 24-70/2.8L @ 55mm, f/3.2, 1/2000, ISO 200
Yes, that is what I want. However, the F828 will give a decent shallow DOF, although not as nice as yours, with small subjects close up, as you have here. It won't blur things as close as ten feet as well either, but it's not too bad. What I'm wondering is how well your camera, and those like it, can do when you have to get a very large subject in the viewfinder, and then have the background blur. And remeber, I can't use much telephoto becasue I'm on teh docks, and can't back up. So I'm probably not using much more than 30 or 40 mm max.
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dwdallam, a wide angle "filter" isn't really a filter, but a supplementtal lens that goes on like a filter. It simply proves a wider angle of view.
The F828 can produce narrow DoF as you show. But the field of view isn't enogh there to fit in a 60' boat.
The F828 doe not have a 28-200mm Ziess lens it has now. Thta is the equivalent 35mm focal length.
DoF is determined the same way for the F828 as it is for an 8x10 view camera. I suggest you learn how that is done and go from there. You sound frustrated. Learning what your camera can and can't do may help.
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It just gives you less depth of field - the size of the subject is inconsequential.
To understand DOF it's helpful to do some outside reading. Here's a link which might help....
Lin
http://members.aol.com/Photoinfo/dof.html (http://members.aol.com/Photoinfo/dof.html)
Right, subject size has no influence on DOF. So can you post something like I wanted so I can see the best possible scenario for the F828?
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I am only thinking out loud. A wider angle lens would let you set up closer to the boat and still get it in the frame, and at the same time require you to focus closer.
While every camera is obedient to the same laws of DoF, not everything is possible with a given camera or maybe even any camera. If I need an f/0.3 lens to get the DoF I want, I had better make other plans. If I need a 20mm lens for my 4x5, probably not going to happen. And so forth.
I decide the shot I want, and do some math. If what I need isn't available to me, I move on.
My wife wanted to take a photo of a woman who repairs musical instruments. The woman worked in a room about the size of a small closet. How do you get a camera on a tripod inside a "shoe box" with a woman working on a cello? And use a couple of strobes with soft boxes? And get everything in focus? And use the Hasselblad she owns with one of the three lenses she owns? Think, plan, and sacrifice some of the things you "need."
"In any event, I'm still waiting on you professionals to get a picture given my parameters above to see how high dollalar [sic] cameras stack up given a large subject, very limited space to 'move away' from the subject, and shallow DOF." What is your budget for this assignment, and how much do I get?
Seriously, move some boats. Get (buy, borrow, rent) a different, more flexible or suitable camera. Get in a boat to get where you need to be. Shoot on a foggy day when the backgound will be fuzzier.
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Like it or not, depth of field is science, not philosphy. Photography is a combination of art and science. Depth of field is science. The only philosophy involved is what you consider to be "in focus." That is your choice of the circle of confusion on the print. A good reference is "The Camera" by Ansel Adams. Adams is a respected name, and although I don't think he has ever personally posted one of his images on LL, he is creditable.
Look at the factors that concern depth of field. To increase depth of field, open the lens up, smaller f number. Increase the focus distance. Increase the focal length of the lens.
But of equal importance, remember that depth of field is to be determined by the print, not on the ground glass or view finder. Depth of field also includes consideration of the print size (call it degree of enlargement of the "negative") and viewing distance and viewing environment. It also involves the subject matter.
The rules or laws of depth of field are the same for your F828 as Adams' 8x10. They do not involve camera format except indirectly through degree of enlargement. Learn them, believe them and you will have no trouble with depth of field. You do not take my word for it.
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dwdallam, I would say you might have a challenge with a camera that has very short focal lenses. To get a 60' boat in the small frame, you will need either a wide angle lens (larger DoF) at closer range (less DoF) or a telephoto (less DoF) from a longer distance (more DoF). With the F828, the "tele" lens is still only 35-40mmish. The things you do have going for you are 1) the small format will require considerable enlargement to get even an 8x10 or 11x14 print, and 2) the lens is relatively fast.
The last factors would be to 1) view the prints from close range under good light. To control this, I would put the print in a small room or hall way where the viewer cannot get too far away and light it up. 2) Try printing on a glossy paper.
For information, I clipped this from Michael Reichman's article Understanding Depth of Field:
"A common complaint about digital cameras is that when using one it's not possible to get nice out-of-focus backgrounds. Why therefore do digital cameras have greater Depth of Field? The reason for this is that the imaging chips on most consumer digitals is very small, around the size of ones smallest finger nail. This means that a normal lens for a format that small is as short as 15mm. A 15mm lens at f/5.6 has Depth Of Field from about 2.5 feet to infinity. Not too much opportunity for selective focus, is there?"
One thing you might try to help decrease the focus of the background is to focus the camera on something closer to the camera. Move the DoF closer to the camera. The auto focus on the camera will focus on the boat. Swith to manual and focus closer. The DoF will keep the boat looking in focus, but will decrease the focus on the background.
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2) Howard, I think your estimate on teh true mm size of the F828 is a little off. I think I read where it is actually 28 to 80mm effective?
Howard is pretty close. "35mm equivalent" is meaningless in the contect of DOF, the actual focal length is what's important. Since the sensor is much smaller tha the 24x36mm of a frame of film, the focal lengths are similarly smaller. If the 828's sensor is 1/5 the size of 35mm film, then the focal length of the lens would be 1/5 of the "35mm equivalent" so a 28-80 "equivalent" would actually be 5.6-16mm. The size difference isn't exactly 5:1, but somewhere in that vicinity.
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Yeah sharpness and DOF are all about perception. Jonathan's sharpening actions have to do with sharpening edges and controlled contrast increases (I think). Applying Photoshop curves selectively to certain areas also does something like the dodging and burning you refer to. However, I want more, I want everything. I want to violate the laws of thermodynamics. I want unlimited DOF, DR, and resolution and I want it now and I want it pretty affordable. Is that too much to ask?
Who says entropy and confusion are irreversible? What do you think the delete button is for, hard disk formatting is for, erasers on pencils are for?
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Specifically, I want to see how other cameras do given this situation:
1) You can't get anymore than 20 feet away from the subject.
2) The subject is BIG, like a 30-60 foot fishing boat, and you need pretty much the entire subject in the frame, or at least 2/3 of it.
I have a question: how much would it increase the price of the Sony F828 to give it a larger sensor, like the Cannons here, while keeping the camera the same in all other respects? One thing I realy like about the Sony is the design. Everything fits perfectly in your hand. For those who have never handled it, you should just to see how it feels. Although I haven't owned the high dollar digitals, I've held them, and nothing feels like that F828.
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In any event, I'm still waiting on you professionals to get a picture given my parameters above to see how high dollalar cameras stack up given a large subject, very limited space to "move away" from the subject, and shallow DOF.
Lin, with all of the snow, you should be able to get a good shot of a large snow plow, huh?
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I don't have any images which would shed much light on this issue. Primarily I use the F828 for macros of highly detailed fine art which is actually at the opposite side of what you are trying to achieve - I shoot for maximum depth of field rather than minimum.
Today here in Colorado I'm covered in snow so won't get a chance to get out and shoot a sample until the weather improves. Perhaps some one else has a representative sample?
Best regards,
Lin
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Noted Howard. But regardless of the technical aspect of DOF, it seems that my camera is challenged to get shallow DOF, regardless. If you can get a shallow DOF using the F828, please post some images with settings and information so I may learn the technique.
Anyone else want to repsond and post some pictures?
PS--I think I took two pictures that demonstrate perfectly the purple fringe problem with the F828. I think someone would be hard pressed to get purple fringe as bad as I did in this particular picture--haha. I posted it at the bottom of the above page.
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JW is correct. I mixed some things up. I'll try agian.
I think the question was how to reduce DoF. To get less, or shallower, DoF, you can:
1. Open up the lens. The larger the actual lens aperture the better to reduce DoF.
2. Use a longer focal length lens.
3. Decrease the focus distance, the distance between the camera and subject.
4. The apearance of in-focus (DoF) can be decreased on the print by making larger prints and/or viewing from a smaller distance. (Of course, if the viewer is far sighted and this isn't corrected, then decreasing viewing distance may increase the DoF for that person.)
5. The apearance of in-focus (DoF) can be decreased on the print by using a sharper lens. Because DoF is the appearance of in-focus, it is easier for the eye to distinguish a difference if the difference is more apparent. The converse is easier for me to understand. It is harder to perceive a difference between an in-focus fuzzy image and a slightly out of focus fuzzy image. A "fuzzier" lens will appear to have greater DoF.
6. The apearance of in-focus (DoF) can be decreased on the print by selecting subjects with crisp edges. Clouds will usually appear to have greater DoF because their edges are fuzzy.
7. Display prints in bright light. This makes it easier for the viewer to see the image and detect focus differences.
8. Make prints that look sharper. Glossy usually appear sharper than matte of textured prints.
Items 1 through 3 are easy. They are hard, physical things on your camera that can "dialed in" or measured.
Items 4 through 8 are more subjective and involve a more personal acceptance of the appearance of in-focus.
There are probably more ways to increase DoF on the print. In my opinion, items 1 through 4 are the heavy weights, more dramatic and easier to see effects.
"... , you cannot seriously be suggesting that you can shoot the same subject, framing, FOV, and distance with an 828 and a 4x5 view camera and get anything remotely approaching similar DOF without using radically different exposure times, f/stop settings, or ISO, are you?"
All I am saying is, there is not different set of DoF facts or equations for an F828, a 35mm, a 6x7, a 4x5 and/or an 8x10 camera. They simply are the same. What ever you do to decrease the DoF on an 8x10 view camera will decrease the Dof on an F828. You do not need to relearn DoF just because you got a new camera.
There are other factors that do come into play that a direct comparison not physically possible. I have never seen a 10mm lens for an 8x10 camera, nor does the F828 have a 12" focal length lens. But that does not change the facts.
"Guys, I feel like my posts are being hijacked for a technilogical discussion each time I post anything on DOF." That is because much of DoF is technical. It is hard to talk about physics without introducing some "science."
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OK, Howard, that makes much more sense. There is one formula for DOF that applies to all cameras, but the range of practical and usable settings (focal length, physical aperture size, etc.) for different-sized camera formats dictate that the extremes of achievable DOF decrease as the size of the film/sensor increases. It's not solely due to camera format, but the range of useful focal lengths and apertures that go with the format.
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you may want to play with the lens blur filter rather than gaussian blur
Yeah, I'm sure that all the blur options have some utility for different sorts of synthetic bokeh and, of course, you can use gradients along with all the other tools in quick mask to vary the effect with any blur tool. However, for landscape images these fancy blur effects are of minimal use (to me at least). I'm sure lots of commercial product shots and fancy magazine ad layouts are routinely done with such trickery.
For my part, I'll limit myself to ideas and let others do the hard work of implementation. I've got thousands of images to work on and doing a lot of Photoshop experiments just for fun is not on the agenda.
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I understand that creating information violates the laws of thermodynamics.
I think you are describing entropy - the more hot air that is poured into a thread the more confusing it becomes. Entropy is a non reversible process, so any attempt to clarify the situation just stirs it up more.
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From what I have seen, softening backgrounds in post-processing can work quite well in trained hands with typical portrait situations, where there is a clear separation between the main subject and background. It probably gets far messier in a situation where you have objects sloping off to the distance and need a realistic gradual fade. And it has little chance of adding "forground blur", such as blurring away branches or a fence in front of the main subject.
About enhancing DOF
a) It is not true that when an image is out of focus, information is irretrievably lost; information from nearby points is mixed together, but in principle it is mathematically possible to unravel this mixing. There is a new technology, being adopted by Zeiss for microscopes, where special lenses produce OOF effects that are uniform instead of increasng with distance from the focal plane. Then subsequent sharpening (akin to what Howard suggests) can achieve great DOF.
Without this special optical treatment Howard's idea could work to sharpen the image at one particular distance. To apply it more generally, you would need details of the distance to each part of the image. I have imagined a camera that records this distance information by sweeping through all focus distances and effectively taking an AF reading at each pixel by local contrast comparisons. Method a) probaby kills of this idea and yet another chance for me to make my fortune.
c) didger's idea might work too: take a sequence of images at many focus distances and blend them, at each point favoring the image with highest local contrast as an indication of being most in focus.
I wonder what software already exists at microscope makers? In addition to Zeiss, Leica comes to mind, so maybe one of them could make a splash in specialized high end digital photography at last.
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BJL, thanks for the info. I won't waste a lot of time trying to focus after the fact. Because out-of-focus spreads information non-randomly, it seems possible to retrieve it. I'll wait for a PS plug-in.
I second Jonathan's comments on the F828 focal lengths and the use of the actual, not equivalent, for DoF.
Maybe (?) this would help dwdallam. Add a supplimental WA lens to the F828. It would allow the entire boat to be in the image and the focus distance greatly decreased.
DiaAzul's last image (stack of hay bales) is interesting. But look at the ground just in front of the stack. It looks to me that the ground looks "out of focus" but the hay just above there is in focus.
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"35mm equivalent" is meaningless in the contect of DOF, the actual focal length is what's important.
That and the fact that the degree of enlargement is typically different for these very different formats: for prints of the same size, enlargement goes up as the format size goes down.
So as far as DOF goes with the 828, the size factor of 4x means that
a) for a given f-stop, uncropped prints of a given size will have 4 times as much DOF as you would get with a 35mm lens giving the same Field of View. That is, using 35m foramt at the 28 to 200mm "equivalent focal lengths".
Thus, you get the same DOF as if you used 35mm format with that equivalent focal length and four times the f-stop.
(Explanation: the 4x focal length change changes DOF by a factor of 4^2=16, the 4x enlargement change gives a factor of 4 in the opposite direction, for an overall factor of 4, and if you also make a 4x change in f-stop, that changes DOF by another factor of 4, getting back to the same DOF.)
P. S. to Howard: before you reply, note that I am explicitly addressing the case of making uncropped prints of the same size from the different formats. We know that you believe that this is a poor way to make DOF comparisons, but under the conditions stated, the conclusions follow from standard optical formulas, so can we leave it at that?
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Maybe (?) this would help dwdallam. Add a supplimental WA lens to the F828. It would allow the entire boat to be in the image and the focus distance greatly decreased.
What is a WA filter, and can I use it with my camera. The F828 is a fixed lens. However, I use a polarizer and lens protector with it.
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I have a question: how much would it increase the price of the Sony F828 to give it a larger sensor, like the Cannons here, while keeping the camera the same in all other respects? One thing I realy like about the Sony is the design. Everything fits perfectly in your hand. For those who have never handled it, you should just to see how it feels. Although I haven't owned the high dollar digitals, I've held them, and nothing feels like that F828.
It's not possible. The lens determines the circle of definition. A lens like the one on the Sony F828 can only produce a circle of definition to fit the sensor designed for it. If a larger sensor were placed in image plane, then the circle of definition would still describe what it does with the Sony except you would have a circle rather than a rectangle of image.
In addition the aperture would be all wrong. As you may know from optical physics the lens diameter plays the major role in determining the amount of light striking the film or sensor plane, thus defining the maximum F rating. The small sensor allows the small lens (relative to 35mm) to achieve the equivalence of a very fast 35mm lens. With a large sensor it takes more light to achieve the same results.
It's just not possible to have a relatively tiny camera with a large sensor unless it also has a lens properly designed to match the sensor. The lens can be larger than necessary, and the additional circle of definition wasted as with crop factor dSLR's, but it can never be smaller than what is required to achieve the needed aperture.
In essence this simply can't work.
Best regards,
Lin
Well, have you seen the F828? It's not a small camera. But more importantly, what I meant was I wonder how much more expensive the F828 would be if they could make it with a large sensor and matching fixed lens, as in 28-200mm Ziess lens it has now. In other words, I wonder what they could do pricewise to have the same design camera work with a large sensor?
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i
Yes, I've had an F828 since they became available. If you designed a similar camera with a large sensor it would be the average size of existing cameras with large sensors. The Canon 350D represents about as small of a camera body as will accommodate a 1.6x crop factor sensor. So if you can imagine a camera with a lens about the size of a Canon 70-200 L attached to the body of a Canon 350D then you will be somewhere close to what it would take. To get the F828's lens speed in a large sensor camera would require a lens with an objective of around 77 mm. To get the zoom would require a length similar to the 70-200 and would probably cost in the neighborhood of $4000. It's doubtful that anyone would buy it because the lens itself would weigh over three pounds.
In short, it won't happen and would be totally impractical...
Best regards,
Lin
Lin, why didn't you say so?!?!? So what is the best shallow DOF you can get using my parameters above for the large subject (60' boat) in a marina type situation (scroll back up a little and see my parameters)?
That would probably be the best real world lesson I could get. No matter how many calculators I use and math models I comprehend, seeing the very limitation of the physical characteristics of the camera, shot by a professional, would allow me to "see' the F828's "best possible" DOF givern my parameters.
After that, if I can't achive the same results, I'll have to do my homework to reproduce what I see here. In other words, if it's impossible to get near what I want, given your superior abilities using the same camera, then spending time trying to get it is a fools errand.
Let me qualify this by saying that I understand knowledge of the technical limitations in conceptual form (math) is indispensible. And I will have a look at what Howard and Jonathan advise.
Jonathan, the portrait is what I would like to have as far as shallow DOF goes.
On the F828, could Sony make the same dedsign, as just a back, with a large sensor? I'd buy that. Like I said, I really like the feel of the Sony design. It feels like a part of my arm after a while.
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I don't have any images which would shed much light on this issue. Primarily I use the F828 for macros of highly detailed fine art which is actually at the opposite side of what you are trying to achieve - I shoot for maximum depth of field rather than minimum.
Today here in Colorado I'm covered in snow so won't get a chance to get out and shoot a sample until the weather improves. Perhaps some one else has a representative sample?
Best regards,
Lin
I did some more marina shots today. I'm thinking the F828 is pretty much always in semifocus, no matter what one does regarding DOF, except for macro when you do get some decent shallow DOF, and some close up shots, where it also gives some. But for large subjects, I'm not having any success at all.
I'll be pleased when someone gets some pictures using my parameters above from the F828, and posts them. Then I'll know for sure.
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The answer is yes, it's possible but certainly not "practical". I could connect my F828 to my Swarovski ST-80 HD or my Meade ETX-90 - shoot from 1000 yards at F14 and produce a blurred background. But in the practical sense of using the camera wide open and shooting from a distance allowable within the native focal length for a reasonable frame it's just not practical.
Not only that, but how are you going to shoot a particular boat in a marina at 1000 yards? You can't becsaue you can only get 50' away from innermost boats, unless you can walk on water. THen you can only get so far becsaue you run into other boats that bloack the view of the boat you need to shoot. But your point is a good one. There is a way to get a shallow DOF using the Sony F828--just impractical, and in some instances, impossible. And your assertion on semantics, from what I can see, is right on too.
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Seriously, move some boats. Get (buy, borrow, rent) a different, more flexible or suitable camera. Get in a boat to get where you need to be. Shoot on a foggy day when the backgound will be fuzzier.
Actually one of the boat captians said he'd move his boat for me in a week or so. Before I borrow or rent a camera, I want to make sure that I can get teh effect I need; hence, the request for some samples. Shooting on a foggy day is an ecellent idea, as we have fog up here frequently. In fact, that may do the trick.
What I have ended up doing for the interim, is taking pictures of interesting angles and objects and parts of the boats. This either fills the frame, or gives me some decent shallow DOF. So if I can't get the 30 degree bow to stern shots I really wanted with shallow DOF, I can get some interesting shots with decent shallow DOF anyway.
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Depth of field doesn't change "because" of subject size, it's determined by aperture and lens and indirectly by sensor size. Where the subject may lie relative to the capture within this depth of field is a different issue entirely. The camera, lens and aperture determine DOF. How the photographer uses this vis a vis the subject is a different issue.
Lin
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Look at the factors that concern depth of field. To increase depth of field, open the lens up, smaller f number. Increase the focus distance. Increase the focal length of the lens.
Ummm, Howard, only one of those three statements are correct. Opening up to a wider aperture will decrease DOF, not increase it. Using a lens of greater focal length will also decrease DOF. Moving the camera away from the subject to increase focus distance is the only factor you mentioned that will actually increase DOF.
As for the rest of your post, you cannot seriously be suggesting that you can shoot the same subject, framing, FOV, and distance with an 828 and a 4x5 view camera and get anything remotely approaching similar DOF without using radically different exposure times, f/stop settings, or ISO, are you?
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I understand that creating information violates the laws of thermodynamics. What I was thinking was to increase the perception of sharpness, not actually add information. After all, DoF is just a perception of in-focus.
I was thinking of commenting earlier (and obviously didn't) that blurring isn't the same as out of focus. A sharply focused image can be blurred, as in camera movement. Have you ever panned as a biker rode by? The bike is sharp, legs blurred. An object behind the subject is very blurred, but might appear sharp if the camera was still. But then the biker would be blurred instead of focused.
I have made images appear sharper (less haze) by burning shadows/dodging highlights of distant areas. Burning/dodging increases the local contrast. Like sharpening, it adds no information.
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1) Can someone take a pisture of a object, such as the boats I have posted, and show me a nice sdhallow DOF--any camera? I just want that for comparison. No Post processing, though.
2) Howard, I think your estimate on teh true mm size of the F828 is a little off. I think I read where it is actually 28 to 80mm effective?
3) OK, here is a great way to achive a nice shallow DOF, from a poster above. Take three pictures of the same object without moving the camera. Change the focus on each so the background is less in focus. Use Adobe to layer it and then use adjustment layer functions to show the blur and keep the focus where you want it. That could work. Still, it would be a masking/selecting nightmare. However, that would mean the objet could not move even a little. That means doing that with boats in a marina would prove virtually impossible. What do you all think?
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I have a question: how much would it increase the price of the Sony F828 to give it a larger sensor, like the Cannons here, while keeping the camera the same in all other respects? One thing I realy like about the Sony is the design. Everything fits perfectly in your hand. For those who have never handled it, you should just to see how it feels. Although I haven't owned the high dollar digitals, I've held them, and nothing feels like that F828.
It's not possible. The lens determines the circle of definition. A lens like the one on the Sony F828 can only produce a circle of definition to fit the sensor designed for it. If a larger sensor were placed in image plane, then the circle of definition would still describe what it does with the Sony except you would have a circle rather than a rectangle of image.
In addition the aperture would be all wrong. As you may know from optical physics the lens diameter plays the major role in determining the amount of light striking the film or sensor plane, thus defining the maximum F rating. The small sensor allows the small lens (relative to 35mm) to achieve the equivalence of a very fast 35mm lens. With a large sensor it takes more light to achieve the same results.
It's just not possible to have a relatively tiny camera with a large sensor unless it also has a lens properly designed to match the sensor. The lens can be larger than necessary, and the additional circle of definition wasted as with crop factor dSLR's, but it can never be smaller than what is required to achieve the needed aperture.
In essence this simply can't work.
Best regards,
Lin
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(http://galleries.visual-vacations.com/images/2004-09-24-0001.jpg)
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"Right, subject size has no influence on DOF."
Actually, it does in a rather indirect way. You would not likely take a photograph of a dime (small subject) the same way you take a photograph of Half Dome (large subject). Your choice of focal length lens and/or focus distance would be significantly different, producing profound effects on DoF.
That is why you can produce very noticible shallow DoF on the barbed wire fence but are having trouble with the marina. Use the same focal length and focus distance in the marina as you did on the fence and you will get exactly the same DoF. You just won't either get the boat in focus or much of the boat in the frame.
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"Right, subject size has no influence on DOF."
Actually, it does in a rather indirect way. You would not likely take a photograph of a dime (small subject) the same way you take a photograph of Half Dome (large subject). Your choice of focal length lens and/or focus distance would be significantly different, producing profound effects on DoF.
That is why you can produce very noticible shallow DoF on the barbed wire fence but are having trouble with the marina. Use the same focal length and focus distance in the marina as you did on the fence and you will get exactly the same DoF. You just won't either get the boat in focus or much of the boat in the frame.
haha yeah exactly. Well, I REALLY want to do large subject shallow depth, but I guess I'll have to find other things to do with the F828. Do you think that add on lens that screws on like a filter would help? Still don't understand how a wider angle will help shallow DOF.
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Guys, I feel like my posts are being hijacked for a technilogical discussion each time I post anything on DOF. For that reason, I'm starting a DOF specific thread. Please post technilogical discussions and arguments there. Thanks
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Would selectively sharpening a digital image increase the DoF? Sharpen the just the edge of the DoF range, both just inside and out side.
I've never tried it or even thought about it before. Any ideas?
I HAVE tried essentially this using the PKSharpener Creative sharpening tool, and yes, you can selectively sharpen areas in an image and you can feather the effect, though I've never really considered that a form of increasing DOF, though I suppose you could look at it that way. However, any kind of sharpening only gets you a rather minimal effect before sharpening artifacts rule the day (or is that ruin the day?). Serious image blurring isn't just a matter of fuzzy edges that you could sharpen, but substantial information loss. You can digitally throw away information in various clever, creative, and visually useful ways, but you can't fake information that's missing altogether, alas, whether the information is missing because of lack of lens or sensor resolution or due to black shadows or blown highlights.
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Here are a couple of narrow depth of field pictures...not boats, but will give some examples of how DOF can be affected.
First is Canon EOS10D, approx 150mm and f2.8
(http://www.pbase.com/mexmoon/image/26781908/large.jpg)
Second is Canon EOS1DII, approx 25mm and f4
(http://www.pbase.com/mexmoon/image/40334729.jpg)
Final image is Canon EOS1DII, 17mm all image is in focus (nearground to background), however, processed with Photoshop CS lens blur filter to simulate narrower DOF (NB this is a quick and dirty example, with more work the effect can be blended in more naturally)
(http://www.pbase.com/mexmoon/image/40689760.jpg)
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I'll do some more digging through the archives, and see what I can come up with...
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Well, have you seen the F828? It's not a small camera. But more importantly, what I meant was I wonder how much more expensive the F828 would be if they could make it with a large sensor and matching fixed lens, as in 28-200mm Ziess lens it has now. In other words, I wonder what they could do pricewise to have the same design camera work with a large sensor?
Yes, I've had an F828 since they became available. If you designed a similar camera with a large sensor it would be the average size of existing cameras with large sensors. The Canon 350D represents about as small of a camera body as will accommodate a 1.6x crop factor sensor. So if you can imagine a camera with a lens about the size of a Canon 70-200 L attached to the body of a Canon 350D then you will be somewhere close to what it would take. To get the F828's lens speed in a large sensor camera would require a lens with an objective of around 77 mm. To get the zoom would require a length similar to the 70-200 and would probably cost in the neighborhood of $4000. It's doubtful that anyone would buy it because the lens itself would weigh over three pounds.
In short, it won't happen and would be totally impractical...
Best regards,
Lin
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the size of the subject is inconsequential.
For all practical purposes, subject size has big consequences. Look at how limited the DOF is in macro photography even when stopped well down.
Beware of comparisons got by changing just one variable in a particular formula which thus introduces the assumption the constancy of the particular collection of other quantities used in that formula. I can easily create different mathematically equivalent formulas that use a different collection of quantites and seem to give quite different conclusions if not interpreted carefully. For example, there are valid DOF formulas that make no mention of focal length, or no mention of f-stop, or no mention of subject distance, or even no mention of CoC; the last one should be very popular!
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One of the best definitions I've ever heard for describing COC (circle of confusion) is:
"A group of professional photographers sitting in a circle discussing depth of field...."
These arguments are primarily difference in semantics rather than differences in substance. The original question concerned the Sony F828 and whether it was "possible" to get a blurred background when shooting a large boat. The answer is yes, it's possible but certainly not "practical". I could connect my F828 to my Swarovski ST-80 HD or my Meade ETX-90 - shoot from 1000 yards at F14 and produce a blurred background. But in the practical sense of using the camera wide open and shooting from a distance allowable within the native focal length for a reasonable frame it's just not practical. The small sensor and associated lens produces a 35mm "equivalency" of 28-200 mm at an "equivalent" aperture. In reality the true focal length quite wide angle and the stated aperture must be multiplied by about four to get a 35mm equivalency. So the F2.8 actually has the optical 35mm characteristics of about F11 while F8 has the optical 35mm equivalence of F32. This is one reason I love the F828 for shooting small, highly detailed fine art macros with this camera. I can shoot hand-held in available light or even with built in flash and get results which are difficult to achieve in the studio with my Canon EOS-1DS, a tripod, specialized lighting, an expensive macro lens and lots of "luck".
It's just not a camera designed for producing a background blur type image and any attempt to make it perform that way simply leads to frustration. It's "horses for courses" and the F828 is a great tool for what it does well.
Best regards,
Lin
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So, what's the question again?
Have you decided what size you want to print and how far away you are going to view the prints? Sorry, but as has been pointed out, the rest of the determination of DoF is mathematics or optics but there's no philosophy there. There may be certain boundary conditions, based on physical science and what can reasonably be manufactured , that could be summarized in inexact generalities, such as "cameras with small sensors usually have difficulty creating shallow DoF" . These are not philosophical statements, however.
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"Now the pity is that there's no way to fake MORE DOF than what you shot."
Perhaps there is. DoF is the zone of "perceived in-focus" image, the part of the image that is acceptably sharp. Would selectively sharpening a digital image increase the DoF? Sharpen the just the edge of the DoF range, both just inside and out side.
I've never tried it or even thought about it before. Any ideas?
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You want fries with that?
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Sorry you were offended by my comments about your depth of field effect.
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Also, I'm really interested in what Howard suggested, but I don't know what a WA filter is.
Here's a picture I took a few days ago. I didn't have it in macro mode, and I forgot the settings. but it shows how the F828, given a very close subject, can produce some shallow DOF. Surprised me:
(http://www.idlethoughtsandchaos.com/photo/cow.jpg)
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dwdallam, a wide angle "filter" isn't really a filter, but a supplementtal lens that goes on like a filter. It simply proves a wider angle of view.
The F828 can produce narrow DoF as you show. But the field of view isn't enogh there to fit in a 60' boat.
The F828 doe not have a 28-200mm Ziess lens it has now. Thta is the equivalent 35mm focal length.
DoF is determined the same way for the F828 as it is for an 8x10 view camera. I suggest you learn how that is done and go from there. You sound frustrated. Learning what your camera can and can't do may help.
I am learning what my camera can and can't do Howard. Have you been reading this thread? (lol)
What I don't understand is how a wider angle lens will give me better shallow DOF on large subjects?
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Lin, what you say is partly true. Where the subject falls within (or outside for that matter) the DoF has nothing to do with DoF. But in practicle terms, most photographers (not even me) set the focus distcance and f/stop and then look for an "in focus" subject. Most photographers select a subject, compose, focus, decide what the DoF should be, set the f/stop, shutter speed and shoot. So, for practicle considerations, size matters. Large subjects will require a wide lens and/or a long focus distance (if the photographer wishes the subject to be within the frame and focused). You simply will not get a full body portrait of a 6' tall person with a 500mm lens on a 35mm camera from 10'. NowI suppose you might argue that the only propblem is teh model is standing in the wrong place, but not practicle. True, if that is all the camera I had, I would ask the model to walk down the block.
DoF is not determined by sensor size - directly. Look at the equations for DoF and point to the term for sensor size. Not there. Now you could say that if I selected a 20x24 camera instead of a 35mm for the above example, I might get what I wanted. But that isn't a practicle method either. I usually won't set the model and tripod up and then decide which camera to use.
Another question here. If I set up a shot with an X-Pan camera (focus distance, f/stop, lens) and then switch from regular to panorama mode, does the DoF change? If you say yes, you would of course be wrong. I could then have the film processed, cut the frame in half and change the DoF back again.
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I am still interested in what some of you can come up with, however, given my parameters. I looked at some professional boat photography sites, but none had what I was looking for. Is it even possible?