Pages: 1 2 [3] 4 5 ... 9   Go Down

Author Topic: expose to the right?  (Read 62070 times)

thsinar

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2066
    • http://www.sinarcameras.com
expose to the right?
« Reply #40 on: November 08, 2007, 09:04:39 pm »

I fully agree with you on this: the technical process, being it for a chemical or a digital workflow, together with its consequences, should be known. It makes, IMO, the creative process much "easier" in the way that it allows creating images without the negative part of the "by chance" factor: as you say it rightly, "you'd be better off exposing properly while making an artistically beautiful image".

After, when knowing excatly what happens in most situations, it is up to each of us to play with this knowledge by using or ignoring it.

Thierry

Quote
Exactly! You may not care about how the ink or the chemicals were made nor should you have to assuming someone else has taken the care and time to do this. As we both agree, without ink, there's no book, without numbers, there is no digital image. But you now control a great deal more of the process than before. You create the numbers, you don't create the film stock or the chemicals. Exposing for digital simply means you are aware of your actions when building numbers, just as exposing for the shadows, developing for the highlights (even if the development wasn't something you personally did) played a role in the quality of your image.

Yes, you'd be better off artistically being half a stop under and capturing a killer image than nailing your exposure and shooting something that isn't at all interesting. But you'd be better off exposing properly while making an artistically beautiful image. The two don't have to be mutually exclusive. I sometimes find this is a straw man argument from those would prefer to ignore best practices in any field (and I'm NOT talking about you specifically). When someone discusses proper technique, others will dismiss this as not being part of the artistic process. Well it is, to some degree.

So having art enter this particular technical discussion is just a distraction (for those of you who are going into that direction). Let's examine the original question here. Its about proper exposure and the belief that medium format is somehow different from DSLR's in this respect. I don't buy it because of the 1's and Zero's. The math is undeniable.

One can say, I don't care, I prefer the way I'm exposing by not using ETTR. That's cool. But as I've tried to point out to others lurking here, you should fully understand what's going on under the hood and probably, like me, test this yourself. I didn't write a fluff piece about how wonderful ETTR is, it clearly has issues (which I'll add, many but not all could be fixed by the manufacturers).
[a href=\"index.php?act=findpost&pid=151418\"][{POST_SNAPBACK}][/a]
Logged
Thierry Hagenauer
thasia_cn@yahoo.com

Wayne Fox

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 4237
    • waynefox.com
expose to the right?
« Reply #41 on: November 08, 2007, 09:23:56 pm »

Quote
Andrew,
With all do respect zero's and one's has as much to do with good images as an ink has to do with good book. You right, without an ink there is no book.
I shot analog for almost 20 years. I shoot strictly MF digital for last 8 years. I operate PS since the PS2.
I consider Photoshop an artistic tool and know it as good as the other guy who spends 6-8 hours a day post processing. When working in darkroom I never cared to know chemical composition of my developers but sure knew how to use them and get the best of each one combo. I knew it because I looked at the results - the prints. Knowing how many atoms of sulphur it takes was left to others, others who look at beautiful fully commercially marketable image and check for signs of banning in the shadows.

Andre
[a href=\"index.php?act=findpost&pid=151416\"][{POST_SNAPBACK}][/a]

I shot analog for over 20 years as well, probably more like 25.  I understood very well how to get a few particular films to perform in a various ways.   I owned a decent size wholesale lab operation which started from purchasing my own Kreonite processor and enlarger, and learning how to make good prints because I didn't like what my lab was giving me. This prompted colleagues to ask me to make prints  for them which got me into that business.  I feel I was (emphasize was) decently skilled in printing.

I don't understand all the 1's and 0's either, and I also consider Photoshop a creative tool, much like various techniques I used in the darkroom.  Common to  both technologies is the simple fact that the better the capture/negative/transparency, the better the resulting image.

However, the workflow and model have changed so dramatically, yet the technology still lags behind.  Metering systems are still based on analog film concepts, and gone are the days where making an image was exactly that ... making images.  Other than a preliminary guide from a video analyzer, custom printing was an exercise in test after test after test, and often multiple prints before everything was just right.

Now we have photoshop and a computer monitor, and the challenge is to get it all done so we can print it right the first time.  But we have cameras that determine exposures as though they had film inside, which as many try to point out, isn't the best way to get an optimum raw capture from a linear device.

So those that do understand the 1's and 0's, such as Andrew, Thomas Knoll etc, explain to us why certain techniques will result in a better raw capture before we go into photoshop, but we still seem be stuck in a world where we think we should expose our digital cameras just like we did our film cameras.  We can't seem to trust them, and when they try and explain the science so we will trust them,  we throw up the shields and excuses about just being an artist and just wanting good images.  What they're telling us helps make better images.

ETTR is about capturing more levels and detail in the RAW capture, taking advantage of the inherit nature of the chip and linear capture.  It is about exposing in a way that is best for linear digital data to get the most levels/gradations/detail out of every capture.  An image using ETTR in most cases will yield a better starting point when you bring it into the raw converter ... the simple fact is it contains a lot more information.  This is especially important if you are doing a lot of work with photoshop, as it sounds like you do, because most steps in photoshop to improve some aspect of the image can have a negative impact on the data in other ways.  

This really isn't theory, and certainly you can choose to ignore it.  But if you are trying to create optimum captures so you can get the very best prints, ETTR isn't that complicated or hard to do.  You just have to believe what these guys are saying and quit believing the image you are seeing on the back of your camera when evaluating exposure.
Logged

bjanes

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 3387
expose to the right?
« Reply #42 on: November 08, 2007, 11:14:41 pm »

Quote
OK, I guess I'm missing something here.  To me you seem to be testing opposite of what I do with ETTR.

I  expose the image to push all values as high as possible without blowing pixels, and typically use a -0.5 to -1.5 EV adjustment to pull the exposure into normal range.  This sounds like you are trying to push the exposure of the normally exposed image to match the ETTR image.

I would assume the only purpose to do a test like this is to confirm that using ETTR and pulling down the exposure in a RAW converter would be a very linear process ... if it isn't very linear then ETTR doesn't work.  I guess you can assume it is linear in either direction, but seems logical that you would pull down the over exposed image to make the test rather than push up the normal one, which would duplicate what ETTR does.  May make no difference what so ever .. I have no clue.

What am I missing?
[a href=\"index.php?act=findpost&pid=151417\"][{POST_SNAPBACK}][/a]

Wayne,

If you want, you could consider the lesser exposure as the normal exposure and the higher exposure as the ETTR exposure. If the process is linear, then the ETTR exposure could be brought down 1 EV in the raw converter to compensate for the 1 EV additional exposure in the camera and the results should be similar as you indicate.  However, with ACR they are not, at least when using the default tone curve.

If your subject dynamic range is equal to that of the camera , then the only proper exposure is to expose fully to the right so as to capture the entire image without clipping either the shadows or highlights. If the dynamic range of the subject exceeds that of the camera, then you have to choose what portion of the subject you wish to capture.

If you are dealing with a short scale subject whose dynamic range is less than that of the camera, then you have some latitude in exposure and can place the exposure either to the left or right without clipping. In this case the exposure should be the one that best takes advantage of the characteristics of the capture medium.

As Ansel Adams explained many years ago for monochrome negative film, one should give the minimum exposure that still records the shadow detail. You can then obtain the desired density in printing. With digital one should place the highlights just short of clipping, and adjust the luminosity with the exposure control of the raw converter. However, if the process is not linear, then the tonal reproduction in the  the image will change with exposure.

My test does not apply to a short scale subject whose dynamic range is less than that of the camera, but such a test would be of interest. The Stouffer wedge has greater dynamic range than the camera.
« Last Edit: November 08, 2007, 11:19:38 pm by bjanes »
Logged

Dustbak

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2442
    • Pepperanddust
expose to the right?
« Reply #43 on: November 09, 2007, 03:06:54 am »

Quote
Shame on you Andre, judging simply by eye is simply not on. It doesn't count unles you pixel peeep. Next, you'll be calling yourself an artist!   

I'd also observe that I've rarely seen any interesting/creative images produced by those overly concerned with the very techy aspects of photography. There are the odd exceptions.
[a href=\"index.php?act=findpost&pid=151413\"][{POST_SNAPBACK}][/a]


This I disagree with. It seems fashion nowadays to cover a lack of knowledge by claiming to be creative. To totally master every technical aspect means a much wider spectrum of tools to feed your creative urges, IMO.

Having said this, I know people that never do the numbers but have an excellent eye on what they are doing and are able to create good results that way, some even stellar results. You would be amazed when checking their numbers how close it will get to what is being considered the 'best/right' way technically.

Technical aspects are subject to creative expression but by no means they are insignificant or 'unworthy'.
« Last Edit: November 09, 2007, 03:11:58 am by Dustbak »
Logged

EricWHiss

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2639
    • Rolleiflex USA
expose to the right?
« Reply #44 on: November 09, 2007, 04:04:49 am »

Quote
This I disagree with. It seems fashion nowadays to cover a lack of knowledge by claiming to be creative. To totally master every technical aspect means a much wider spectrum of tools to feed your creative urges, IMO.

Having said this, I know people that never do the numbers but have an excellent eye on what they are doing and are able to create good results that way, some even stellar results. You would be amazed when checking their numbers how close it will get to what is being considered the 'best/right' way technically.

Technical aspects are subject to creative expression but by no means they are insignificant or 'unworthy'.
[a href=\"index.php?act=findpost&pid=151466\"][{POST_SNAPBACK}][/a]


I think its fair to assume that anyone even reading this forum has at least some interest in the technical aspects of photography.  But this ETTR stuff needs to be put in perspective. Its no where near as important as lighting and composition and a whole bunch of other stuff at least IMHO. Its way down on my list, especially now with DR that is bigger than a lot of film.  You do need to know how to use your tools but the goal is always to make a good image, not to feel warm inside about your 0's and 1's.



So those of you that are doing ETTR on the majority of your images, are you setting your favorite RAW converter to linear when you push down the exposure?  Then what are you doing to the image?   Do you add color saturation or fiddle with the curves?   I am still struggling to make my color images look better especially with really saturated colors like with flowers and stuff and sometimes skin.

Thanks,
Eric
« Last Edit: November 09, 2007, 04:07:26 am by EricWHiss »
Logged
Rolleiflex USA

Jonathan Wienke

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5829
    • http://visual-vacations.com/
expose to the right?
« Reply #45 on: November 09, 2007, 06:44:30 am »

Quote
So those of you that are doing ETTR on the majority of your images, are you setting your favorite RAW converter to linear when you push down the exposure?

Yes. Or at least linear is my default setting in ACR. If I want to boost contrast, I'll pull in the endpoints of the curve so that the histogram fills most of the space between 0 and 255. And I may tweak the midtones by setting a point or two in the middle of the curve somewhere and pulling it up or down to get the overall tonality I want. But linear is always my starting point, and I always shoot as far to the right as I can without clipping non-specular highlights.

Exposing to the right may mean that you don't get exactly what you want with all RAW conversion settings at their default values. But it always means that you get a file with more usable image data that can be tweaked and adjusted more aggressively before falling apart than one can get by any other exposure strategy. I have very little concern for what I get with all default settings; what matters to me is the result I get after using all of the techniques at my disposal to make the image be all it can be. And ETTR is what always works best under those circumstances, whether you shoot with a MFDB, DSLR, or a digicam.
Logged

bjanes

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 3387
expose to the right?
« Reply #46 on: November 09, 2007, 07:50:16 am »

Quote
Yes. Or at least linear is my default setting in ACR. If I want to boost contrast, I'll pull in the endpoints of the curve so that the histogram fills most of the space between 0 and 255. And I may tweak the midtones by setting a point or two in the middle of the curve somewhere and pulling it up or down to get the overall tonality I want. But linear is always my starting point, and I always shoot as far to the right as I can without clipping non-specular highlights.
[a href=\"index.php?act=findpost&pid=151478\"][{POST_SNAPBACK}][/a]

Jonathan,

What do you mean by linear? To get a linear response from ACR, one sets brightness, contrast and the black point to zero on the main tab and the point curve in the curves tab to linear. Or is your default merely setting the point curve to linear and, possibly, the black point to zero on the main tab?

In the first case, the converted image will be very flat even after you set the black and white points, and will require manipulation of the mid-tones as well. All this can be done, but it seems to me to be a lot of extra work.

Bill
« Last Edit: November 09, 2007, 07:51:00 am by bjanes »
Logged

Jonathan Wienke

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5829
    • http://visual-vacations.com/
expose to the right?
« Reply #47 on: November 09, 2007, 10:35:53 am »

I have the shadow contrast, and saturation sliders set to 0. This gives a kind of flat initial look, but I can shoot ETTR, adjust exposure as needed, and then tweak the image with the curve control in ACR as desired to get the optimal amount of global contrast and overall tonality. If the image is still flat, I simply boost local contrast while running my midtone sharpening action. I run the same process on every image; I simply adjust the parameters of each step to achieve whatever look I'm going for.

http://www.visual-vacations.com/Profession...s/Portraits.htm

Adding punch to a flat image is easy; you simply adjust the black/white points via levels/curves or boost local contrast with large radius USM. Trying to tame down and overly contrasty image is much harder, and in many cases impossible if channels have been clipped.
Logged

AndreNapier

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 422
    • Andre Napier Photography
expose to the right?
« Reply #48 on: November 09, 2007, 11:30:05 am »

I did not wanted to sound like an artist hiding his ignorance behind his creation. In the past I used to scan images on state of an art Scitex-Creo scanner and had a pretty good hand of. My prints were perfect to me and my clients. In the quest to improve even farther I decided to have selected negatives rescan by first class tech on drum Tango. I supervise the process. The tech never took a look at the negatives during his work. He have completed the project just by numbers. I received a bunch of mathematically perfect images with the most information displayed in the most unpleasant way. I was never able to recover the looks the way I envision them even after days in PS.
I constantly look at the work published in the international top fashion magazines and have to conclude that over 90% of it does not meet the criteria of perfectly mathematically exposed images.
As I said at the beginning I must be the dumbest photographer who just want to be able create images that people love to look at and pay money for it. When I look at my prints I see silver or ink
but I do not see any zeros or ones. "Knowledge is a blessing and a curse" I try to remember it and balance it every day. I am done with this subject.
http://AndreNapier.com
Logged

EricWHiss

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 2639
    • Rolleiflex USA
expose to the right?
« Reply #49 on: November 09, 2007, 12:00:16 pm »

Quote
.
.
.
 "Knowledge is a blessing and a curse" I try to remember it and balance it every day. I am done with this subject.
http://AndreNapier.com
[a href=\"index.php?act=findpost&pid=151516\"][{POST_SNAPBACK}][/a]

I agree with that Andre!    But let me add to that with another expression and old one.  "To a hammer, everything looks like a nail."  

Well I try to strike a balance too. Everytime I learn something new wrt digital tech, I have to play with it for a while on the forefront until it gets absorbed into my subconscious level where hopefully I just do it instead of having to think about it while shooting. Problem with digital stuff is there is something new nearly everyday!
« Last Edit: November 09, 2007, 12:00:59 pm by EricWHiss »
Logged
Rolleiflex USA

Jonathan Wienke

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5829
    • http://visual-vacations.com/
expose to the right?
« Reply #50 on: November 09, 2007, 12:47:23 pm »

Quote
I decided to have selected negatives rescan by first class tech on drum Tango. I supervise the process. The tech never took a look at the negatives during his work. He have completed the project just by numbers. I received a bunch of mathematically perfect images with the most information displayed in the most unpleasant way. I was never able to recover the looks the way I envision them even after days in PS.

And was the problem with the images due to exposure or bad color? If color is good, but tonality needs tweaking and you can't fix it, your photoshop skills are quite lacking. There are many ways to adjust tonality without affecting color, such as doing a curve adjustment layer with luminance blend mode, or converting to LAB and doing curves on the L channel. If the colors weren't right in the scan, then the scanning profile was bad, and fixing that can be very difficult unless you have a better profile and can assign it to the files. But neither of those things has any validity as an argument against ETTR, especially when comparing a film scan to digital capture. Given the linear nature of digital capture vs the nonlinear nature of film, your argument is comparing apples to anchovies.
Logged

bjanes

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 3387
expose to the right?
« Reply #51 on: November 09, 2007, 02:23:08 pm »

Quote
Adding punch to a flat image is easy; you simply adjust the black/white points via levels/curves or boost local contrast with large radius USM. Trying to tame down and overly contrasty image is much harder, and in many cases impossible if channels have been clipped.
[a href=\"index.php?act=findpost&pid=151506\"][{POST_SNAPBACK}][/a]

Adjusting the black and white points in levels will increase the contrast in all areas of the image, but it might be better to determine which tonal regions of the image need a contrast boost and apply an S curve after setting the black and white points in a curve. The inflection point of the S curve can be determined by locating the critical tones with the eyedropper. The S curve adds contrast in the critical areas of the image and compresses tones in noncritical areas. This local compression helps if the dynamic range of the resulting image exceeds that of the display device.

Large radius USM is an interesting option, but the process might destroy details that one wishes to preserve.
Logged

Toby1014

  • Newbie
  • *
  • Offline Offline
  • Posts: 42
expose to the right?
« Reply #52 on: November 09, 2007, 02:59:20 pm »

Quote
And was the problem with the images due to exposure or bad color? If color is good, but tonality needs tweaking and you can't fix it, your photoshop skills are quite lacking. There are many ways to adjust tonality without affecting color, such as doing a curve adjustment layer with luminance blend mode, or converting to LAB and doing curves on the L channel. If the colors weren't right in the scan, then the scanning profile was bad, and fixing that can be very difficult unless you have a better profile and can assign it to the files. But neither of those things has any validity as an argument against ETTR, especially when comparing a film scan to digital capture. Given the linear nature of digital capture vs the nonlinear nature of film, your argument is comparing apples to anchovies.
[a href=\"index.php?act=findpost&pid=151529\"][{POST_SNAPBACK}][/a]


Jonathan, looking at your portrait link and reading your comments to Andre Napier, it seems like a joke when you are talking about ETTR and photoshop skills.

Perhaps it is time for you to brush up your portrait skills.

Cheers

Toby
Logged

jing q

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 596
    • we are super
expose to the right?
« Reply #53 on: November 09, 2007, 03:21:27 pm »

Quote
I think its fair to assume that anyone even reading this forum has at least some interest in the technical aspects of photography.  But this ETTR stuff needs to be put in perspective. Its no where near as important as lighting and composition and a whole bunch of other stuff at least IMHO. Its way down on my list, especially now with DR that is bigger than a lot of film.  You do need to know how to use your tools but the goal is always to make a good image, not to feel warm inside about your 0's and 1's.
So those of you that are doing ETTR on the majority of your images, are you setting your favorite RAW converter to linear when you push down the exposure?  Then what are you doing to the image?   Do you add color saturation or fiddle with the curves?   I am still struggling to make my color images look better especially with really saturated colors like with flowers and stuff and sometimes skin.

Thanks,
Eric
[a href=\"index.php?act=findpost&pid=151468\"][{POST_SNAPBACK}][/a]

Wanted to chip in here as I'm working on an Aptus 75S file here...ETTR is a pain in the ass. I don't bother anymore. I find the colours and look I want eaier to achieve by getting an image with good midtones rather than pushing the data all the way to the right.

The issue here is that even though there is more information, by the time I go home to process the image I may have forgotten how the hell I wanted to scene to look in the first place. It's great if you have all day to experiment in photoshop but I think alot of us appreciate the KISS motto (keep it simple, stupid)
So I lose abit of data (which is usually negligible unless we're talking about a very dark image...), but when I got the shot I have already confirmed how I want it to look

I treat it like a slide, I know that overexposing it abit and then bringing it down in photoshop after scanning may be possible but it requires too much minute tweaking to go back to the original look.
It's like scanning film in the past. I used to get these really flat drum scans (which I'm sure are full of data...) but oh my god the amount of time taken to tweak it to the look I want! I'm not a bloody computer scientist for christ's sake.
I'm sure my DI artist can appreciate a technically perfect file for his own tweaking but for me, KISS.

I also find that skin tones don't respond accurately to how I imagine (very minute differences in contrast and tonalities that I can't place my finger on but it just doesn't feel...right)

So I read all the technical data that states that it's all the same but my experience speaks otherwise. Just my personal experience. Now I have to get back to tweaking that bloody ETTR image in photoshop.
Logged

AndreNapier

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 422
    • Andre Napier Photography
expose to the right?
« Reply #54 on: November 09, 2007, 03:22:38 pm »

Quote
And was the problem with the images due to exposure or bad color? If color is good, but tonality needs tweaking and you can't fix it, your photoshop skills are quite lacking. There are many ways to adjust tonality without affecting color, such as doing a curve adjustment layer with luminance blend mode, or converting to LAB and doing curves on the L channel. If the colors weren't right in the scan, then the scanning profile was bad, and fixing that can be very difficult unless you have a better profile and can assign it to the files. But neither of those things has any validity as an argument against ETTR, especially when comparing a film scan to digital capture. Given the linear nature of digital capture vs the nonlinear nature of film, your argument is comparing apples to anchovies.
[{POST_SNAPBACK}][/a]

Jonathan,
I really tried to restrain myself but I guess by know you really have asked for it. I checked the link that you have posted ( visual- vacation ) and have to conclude that with all your linear knowledge all your pics. posted are as flat, dull and Kmartish as they possibly can be. The fact that you do not get the point is a point by itself. Good luck to you assuming that my PS skills are lacking. I do not think that there is a hope that one day you will see past the 1's and 0's and realize where you really standing.

To all of the rest of you guys,
sorry for being so impulsive. I realize it is time for me for extended vacation from LL. I take full responsibility for this personal attack. It is just my opinion and I may as well be wrong.

Respectfully Yours
[a href=\"http://AndreNapier.com]http://AndreNapier.com[/url]
Logged

digitaldog

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 20630
  • Andrew Rodney
    • http://www.digitaldog.net/
expose to the right?
« Reply #55 on: November 09, 2007, 03:25:11 pm »

Quote
To all of the rest of you guys,
sorry for being so impulsive. I realize it is time for me for extended vacation from LL. I take full responsibility for this personal attack. It is just my opinion and I may as well be wrong.

Respectfully Yours
http://AndreNapier.com
[a href=\"index.php?act=findpost&pid=151565\"][{POST_SNAPBACK}][/a]

Well both posts (yours and toby's) were uncalled for (and there's nothing respectfully being said here). We'd love to have you back when you regain some manners.
« Last Edit: November 09, 2007, 03:27:10 pm by digitaldog »
Logged
http://www.digitaldog.net/
Author "Color Management for Photographers".

jing q

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 596
    • we are super
expose to the right?
« Reply #56 on: November 09, 2007, 03:27:02 pm »

Quote
Jonathan,
I really tried to restrain myself but I guess by know you really have asked for it. I checked the link that you have posted ( visual- vacation ) and have to conclude that with all your linear knowledge all your pics. posted are as flat, dull and Kmartish as they possibly can be. The fact that you do not get the point is a point by itself. Good luck to you assuming that my PS skills are lacking. I do not think that there is a hope that one day you will see past the 1's and 0's and realize where you really standing.

To all of the rest of you guys,
sorry for being so impulsive. I realize it is time for me for extended vacation from LL. I take full responsibility for this personal attack. It is just my opinion and I may as well be wrong.

Respectfully Yours
http://AndreNapier.com
[a href=\"index.php?act=findpost&pid=151565\"][{POST_SNAPBACK}][/a]

hi Andre, I think it would be a waste to take an extended vacation based on the forceful opinions of some people who don't seem to appreciate practical experience...
Logged

jing q

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 596
    • we are super
expose to the right?
« Reply #57 on: November 09, 2007, 03:31:10 pm »

Quote
Maybe this is a dumb question....but just curious what everyone else is doing...

Seemed like expose to the right was the rule with DSLRs but since shooting my Rollei/P20 and Leica DMR  (which has similar dynamic range and is also 16bit)  I have found that I am getting better results exposing the images for the look I want rather than exposing to the right and pushing down in post.  In fact I might be crazy but to me it seems my files look best if I expose for the final rather than push down, and sometimes I find if I have to make exposure adjustments in post that the files look better if I push up rather than push down.  Am I crazy?
[a href=\"index.php?act=findpost&pid=150443\"][{POST_SNAPBACK}][/a]

Also, guys who are advocating the ETTR method, have you used MFDBs? the original poster noted that this was applicable to his experience with his MFDB and leica DMR.
And some of us have noticed the same issues.
for my 1Ds MKII, ETTR does help with details but when it comes to MFDB I find that it's more useful to expose for midtones or slightly underexposed even.. (on my Aptus histogram I try not to get any overexposure past +0.2 even in contrasty scenes)
Logged

JeffKohn

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1668
    • http://jeffk-photo.typepad.com
expose to the right?
« Reply #58 on: November 09, 2007, 03:32:26 pm »

The thing I'm not clear on is whether ETTR really gives you more data in your final image, as opposed to just somewhat better data. Yes, shifting exposure to right means more tonal values captured in the RAW file. But if you shift the exposure back to the left in the RAW convertor, aren't you going to be discarding those extra tonal values since the exposure slider works on the linear data?

For example I have a low contrast scene, and with ETTR I'm able to overexpose the image by 2 stops. Meaning items in the scene that should be recorded in the bottom most stop, let's call it zone 1, actually get recorded two stops brighter in zone 3. Zone 3 has more values in it than Zone 1, so you get a better capture, right? But if I slide the exposure slider in ACR to put that item back in Zone 1 where it belongs, aren't those extra data values going to get discarded? Remember we're operating on linear data, and zone 1 has fewer data values in which to store its part of the image.

Now I guess those values that get shifted back down to zone 1 will be cleaner, kind of like the pixel binning that some cameras do at high iso. So ETTR would still have some benefit, I just wonder if maybe it's less benefit than some might be thinking.

It would seem to me that to really make the most of those extra values you captured with ETTR, you'd have to wait and shift the data to the left in post-processing, after you have a gamma corrected image with more data values in the shadow tones. The problem with this is that getting the tonal relationships between shadows, midtones, and highlights to look right may not be such an easy task. Which I think maybe is the point Eric was originally getting at - if the ETTR image looks different even after shifting back to the right, and if one prefers the "look" of the non-ETTR image, any theoretical/technical advantage of ETTR is for naught.
Logged
Jeff Kohn
[url=http://ww

Jonathan Wienke

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 5829
    • http://visual-vacations.com/
expose to the right?
« Reply #59 on: November 09, 2007, 05:01:07 pm »

Quote
The thing I'm not clear on is whether ETTR really gives you more data in your final image, as opposed to just somewhat better data. Yes, shifting exposure to right means more tonal values captured in the RAW file. But if you shift the exposure back to the left in the RAW convertor, aren't you going to be discarding those extra tonal values since the exposure slider works on the linear data?

No, because the linear data are being recalculated in a 16-bit space, so when you shift the exposure control down the tonal scale, you are replacing bits that would normally be noise with bits that are actual image data. Imagine you have a 16-bit camera and shoot at base ISO where there is (just as an example) 4 bits worth of noise, and you take 2 frames, the first 1 stop underexposed and the second 1 stop overexposed. With the underexposed shot, when you apply the +1 exposure correction, you are keeping all 4 bits of noise, and adding an additional invented bit to move everything one stop op the tonal scale, for a total of 5 bits of something other than actual image data. With the ETTR shot, if you didn't clip any highlights and apply a -1 adjustment in the RAW converter, you are discarding the least significant bit, and moving all of the others over one position. So you have 3 bits of noise instead of 5 bits of (noise + interpolation).

Quote
The problem with this is that getting the tonal relationships between shadows, midtones, and highlights to look right may not be such an easy task. Which I think maybe is the point Eric was originally getting at - if the ETTR image looks different even after shifting back to the right, and if one prefers the "look" of the non-ETTR image, any theoretical/technical advantage of ETTR is for naught.

If this is truly an issue, the you should consider other RAW converter options (ACR doesn't have this problem).
« Last Edit: November 09, 2007, 05:14:09 pm by Jonathan Wienke »
Logged
Pages: 1 2 [3] 4 5 ... 9   Go Up