Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: BernardLanguillier on July 16, 2009, 09:01:26 am
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Michael,
Thanks for the review.
These various options to focus legacy backs are interesting, but isn't the real solution life view in back?
Cheers,
Bernard
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I don't think the geared fall of up to 30mm in the rear is a problem.
It effectively translates into upwards of 30mm rise in the front.
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Live view is only a solution if there is a strong digital magnification available, the way it is, for example, on the Panasonic G1 and GH1.
Michael
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I don't think the geared fall of up to 30mm in the rear is a problem.
It effectively translates into upwards of 30mm rise in the front.
Good observation. I couldn't fathom why an architectural camera would be designed with 30mm fall and only 10mm rise, unless they expect their customers to photograph mainly archeological excavations.
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to minimize zero position parallax? compensated by equiv rear fall ...
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Live view is only a solution if there is a strong digital magnification available, the way it is, for example, on the Panasonic G1 and GH1.
Michael
Sure, Nikon D3x implementation is perfect, click on a button and you zoom to a pre-defined level of enlargement, pixel level or more.
Am still amazed that backs don't enable this.
Cheers,
Bernard
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Sure, Nikon D3x implementation is perfect, click on a button and you zoom to a pre-defined level of enlargement, pixel level or more.
Am still amazed that backs don't enable this.
Cheers,
Bernard
I am using a D3x and the three PCE lenses- - The optics are great wide open- IF - focussed correctly -The only way I can do that is using Live-view and a (hood) loop
Using tilt makes Live-View even more important.
If the D3x says it is sharp - and the Dot appears - I can make within the room of the dot six pictures - only one is truly sharp
If i use auto focus at near infinity with lots of small detail the auto focus is near but not accurate...
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I am using a D3x and the three PCE lenses- - The optics are great wide open- IF - focussed correctly -The only way can do that is using Live-view and a (hood) loop
Using tilt makes Live-View even more important.
If the D3x says it is sharp - and the Dot appears - I can make within the room of the dot six pictures - only one is truly sharp
If i use auto focus at near infinity with lots of small detail the auto focus is near but not accurate...
Yep. The D3x has arguably the best AF in the world, and yet it is unable to tap fully into the potential of a AA filter 24 MP sensor, think of the waste of information taking place with MFDB not being focused because of the lack of in back live view... I am really surprised that most back owners don't list this as their #1 priority for future enhancement.
It leads me to think that most of these guys do in fact not really need the resolution.
Cheers,
Bernard
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think of the waste of information taking place with MFDB not being focused because of the lack of in back live view... I am really surprised that most back owners don't list this as their #1 priority for future enhancement.
It leads me to think that most of these guys do in fact not really need the resolution.
err? A misfocussed capture still has the resolution... just shifted back or in front of the focussed motif. We are only just iditos that we don't care about front- or backfocus.
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err? A misfocused capture still has the resolution... just shifted back or in front of the focused motif. We are only just idiots that we don't care about front- or back focus.
I'm curious why focus adjust is available in the more recent Canons, Nikons, Sonys, etc. but not Mamiya/ Phase One, Hasselblad, etc. It would seem the resolution, as Michael said during the video, demands it.
Mike.
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As far as I heard Sinar measures and adjustes its lenses for the arTec in a way that you can not focus over infinity-meaning for every distance longer than lets say 10-15m you should be fine if you turn the focus to the end (at least with the wider lenses).
I dont know if Arca does the same, but if they do you are at least fine at infinity.
Now for the shorter distances the question is what is more precise - the groundglass or a distance meter like the Leica. Even if you measure the distance correct you have to turn the lens to the correct position. Lets say you measure 7m you still have to make up your mind if you dont have 7m on the scale.
SO I agree for shoter distances lieve view would be great.
On the other side I dont find the ground glass that bad. I gues here its an advantage if you use Rodenstock lenses, since a 35/4.0 HR lens compared to a Schneider5.6-lens+ center filter could make quite a difference in brightness on the groundglass.
I like the "orange grips" on the Rm3d.
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err? A misfocussed capture still has the resolution... just shifted back or in front of the focussed motif. We are only just iditos that we don't care about front- or backfocus.
Hum... like in this image?
More seriously, are saying that you don't feel the need for live view on your back?
Cheers,
Bernard
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Hum... like in this image?
More seriously, are saying that you don't feel the need for live view on your back?
Cheers,
Bernard
Working with a Linhof and a P65 I can say, that Live view like Canon has it would be the most important new feature.
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are saying that you don't feel the need for live view on your back?
I don't feel the inevitable need, no. But live view would certainly be a very helpful feature!
I don't think that by now all photographs were out of focus and now after the invention of live view we finally can shoot sharp
I honestly smiled a little bit about Michael's comment in the video about the screen in the Phamiya with the P65+. With the P65+ now we need it and we didn't need it with the P45+? I use split image and microprism screens since years. Even in my small 10MP DSLR because AF is simply not accurate enough especially with wide angles at distances near infinity. And in the small APS-C finder the screen is just too small to focus manually.
I definitely don't need live view for my Contax (with P45) - I have yet to miss accurate focus (from tripod, of course) as the split screens work really, really great. Though it would be helpful to have live view - here I don't miss it.
Regarding the Cambo WRS I use I see it pretty much as "paratom". I shoot the majority of my motifs with the lens set to infinity and this is save ground. Close distances from nearest to about 6 meters distance (talking about the Digitar 47XL here) are not that much of a problem as I can focus these distances pretty well on the groundglass (with a 6x aspherical loupe; and especially with my new fresnel screen). The real challenge are distances near but not quite infinity. Here I am using such a laser distometer from the very beginning and once you figured out how to set the lens it works pretty well. But, of course, it's not accurate enough if you shoot wide open. Exactly here I find Arca Swiss' approach very promising as it seems to be possible to set the distance on a very, very fine scale.
Furthermore I am seriously thinking about the Digaron HR lenses as they are faster as the Digitars. With the faster lenses I could use a GG with split image (preferably a bright screen with split of Bill Maxwell or something similar). At f5.6 with the Digitars the split goes dark so it's unusable here... unfortunately. A well mounted split screen would make live view irrelevant for me personally (as it is the case with my Contax'). Too, I wouldn't buy a new back just because of the live view feature as long as it is possible to work accurate without (and it is IMHO).
So... I think I will keep working (and working around) the "traditional" way for some time. Having said that a well working live view would definitely be a huge improvement. Then again I know that for other purposes than mine live view is more important - so I really understand why so many photographers ask for live view. For me personally: very nice to have but not essential.
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I'm curious why focus adjust is available in the more recent Canons, Nikons, Sonys, etc. but not Mamiya/ Phase One, Hasselblad, etc. It would seem the resolution, as Michael said during the video, demands it.
The reason is simple. CCD vs CMOS. The MF back makers believe that at this point CCD offers superior image quality. (Or, maybe it's because Kodak and Dalsa can't or won't make CMOS sensors in that size). CCD can't do Live View as it's currently implemented.
If Phase One and Hasselblad decide to switch to CMOS on a future generation back then Live View and video will both be possible.
How about a 90MB CMOS sensor, Live View with magnification, a large OLED screen, and 4K raw video capability?
RED should have a camera with similar capabilities within 18 months. Will Hasselblad and Phase One?
Michael
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The reason is simple. CCD vs CMOS. The MF back makers believe that at this point CCD offers superior image quality. (Or, maybe it's because Kodak and Dalsa can't or won't make CMOS sensors in that size). CCD can't do Live View as it's currently implemented.
If Phase One and Hasselblad decide to switch to CMOS on a future generation back then Live View and video will both be possible.
How about a 90MB CMOS sensor, Live View with magnification, a large OLED screen, and 4K raw video capability?
RED should have a camera with similar capabilities within 18 months. Will Hasselblad and Phase One?
Michael
Hasselblad and Phase are smart to let RED go to market first with a bleeding edge 90MB CMOS platform. It won't be a big surprise if the big CMOS sensor is riddled with issues. It won't be a big surprise either if RED's camera isn't out in the marketplace in 18 months.
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I'm curious why focus adjust is available in the more recent Canons, Nikons, Sonys, etc. but not Mamiya/ Phase One, Hasselblad, etc. It would seem the resolution, as Michael said during the video, demands it.
Mike.
It has been present in the H3D for sometime except it is carried out in the factory.
If you look in the System Status menu, there is a unique Focus Calibration ID which is created in the factory during final assembly. This ensures that whatever lens is used, AF is where the customer placed it. No individual adjustment of lenses if required as I assume our manufacturing tolerances are tighter than Nikon and Canon.
We also compensate automatically for aperture dependent focus shift.
Therefore I do not think the D3x is the best Autofocus camera in the world.
Best,
David
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AF is where the customer placed it.
David, what are the measures of the AF field?
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Sure, Nikon D3x implementation is perfect, click on a button and you zoom to a pre-defined level of enlargement, pixel level or more.
Am still amazed that backs don't enable this.
Cheers,
Bernard
Bernard, we are not being belligerent in not offering this feature. It is simply not available (yet) at sensor level. Of course, if it were possible we would use it!
Just because a medium format system doesn't have live view does not then render it impossible to focus. That is a rather naive attitude.
Best,
David
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David, what are the measures of the AF field?
Hi Thomas,
Not sure I understand (sorry!). Do you mean the number of AF points?
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Not sure I understand (sorry!). Do you mean the number of AF points?
well, my bad English... sorry!
I mean the size/diameter of the (center) AF point.
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well, my bad English... sorry!
I mean the size/diameter of the (center) AF point.
Page 88 of the H3D manual...
The point of focus is determined according to the vertical and horizontal areas (see illus 4.) within the central rectangular zone on the focusing screen.
See attachment!
[attachment=15498:Picture_2.png]
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Page 88 of the H3D manual...
I have neither the H3D nor its manual, sorry
Thank you!
So when you shoot a motif from a very steep angle (10° or so) you'll have massive frontfocus, right? And if you want to shoot through a grid or a fence they will be sharp but if you want the background sharp you have to focus manually.
I assume your solution works very well on flat, contrasty motifs... but those motifs are not always the case.
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I have neither the H3D nor its manual, sorry
Thank you!
So when you shoot a motif from a very steep angle (10° or so) you'll have massive frontfocus, right? And if you want to shoot through a grid or a fence they will be sharp but if you want the background sharp you have to focus manually.
I assume your solution works very well on flat, contrasty motifs... but those motifs are not always the case.
Actually not in my experience, no. (Regarding front focus)
The actual AF target area is very small in the viewfinder so you can easily place focus accurately - is shooting through a grid or a fence as you mention.
Please try it (if you can!) on an H3D.
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Actually not in my experience, no. (Regarding front focus)
I mean this constellation, here with a ruler... but maybe at a steeper angle as the ruler in this image.
[attachment=15499:Hscreen.jpg]
How should the AF know that you don't want the outer circle of the AF field in focus?
Anyway... I think you agree that there are situations where you need manual focus. And here live view (or other tools) help a lot. So as good as your AF might be, it's not appropriate for all purposes.
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It has been present in the H3D for sometime except it is carried out in the factory.
If you look in the System Status menu, there is a unique Focus Calibration ID which is created in the factory during final assembly. This ensures that whatever lens is used, AF is where the customer placed it. No individual adjustment of lenses if required as I assume our manufacturing tolerances are tighter than Nikon and Canon.
We also compensate automatically for aperture dependent focus shift.
Therefore I do not think the D3x is the best Autofocus camera in the world.
Best,
David
David: No intention of being belligerent here, but (assuming for a moment) that Phase One and Hasselblad are creating somewhat equivalent products... in the video Michael states that he runs into trouble using autofocus with his Phase One/ Mamiya camera and the P65+ back, to the point that he uses the Mamiya 2X magnifier on the viewfinder and a microprism focusing screen to ensure accurate focus. Are you saying that such focusing problems don't exist with the H3DII-50 for example? I don't mean to put you on the spot, but I'm sure others would like to know as well.
Mike.
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David: No intention of being belligerent here, but (assuming for a moment) that Phase One and Hasselblad are creating somewhat equivalent products... in the video Michael states that he runs into trouble using autofocus with his Phase One/ Mamiya camera and the P65+ back, to the point that he uses the Mamiya 2X magnifier on the viewfinder and a microprism focusing screen to ensure accurate focus. Are you saying that such focusing problems don't exist with the H3DII-50 for example? I don't mean to put you on the spot, but I'm sure others would like to know as well.
Mike.
Well, it is very nice of Michael to say he has autofocussing issues with his P65+. ;-)
I do agree though that focussing accurately manually can be a challenge so I assume a 2x magnifier would help. I did not sit through the whole video so I am not sure in which context Michael's comments were made.
Anyway, yes please do put me on the spot!
We recognised a few years back that as the resolution of sensors began to increase, the precision of the system was much more important. Not just the focussing but also things like fitment of the digital back to camera had to be tighter, flatter for example with a lower tolerances of error. Even minor things such as the flatness of the IR filter glass can cause issues!
Film and smaller sensors (think 16MP) were very good as masking inefficiencies in manufacturing, larger (think 50 / 60 MP) are very unforgiving!
With the 16MP we had virtually no complaints of focus errors but as we began to introduce 22MP and more so 39MP we saw the need for some changes to protect for the future.
The 'mechanical' method was solved with the Imacon backs by supplying shims to adjust back position to film / sensor plane. The smallest shim is only 50microns and this WILL make a positive difference to focussing accuracy. So you can see how important precision really is.
The beauty of controlling all parts of the camera system is that as well as tightening up manufacturing tolerances we also have a large amount of data from all these parts which again can add more degrees of accuracy.
So as I mentioned above every camera is custom calibrated in final production with regards to focus precision. Then further accuracy is achieved by correcting aperture dependent focus shift.
In summary, as we manufacture all parts and have all the necessary data AND the ability to communicate all useful data (The camera parts are 'networked on a databus) we can make incremental steps in increasing precision.
So after my long winded reply I would absolutely say I don't believe there are auto focussing accuracies with the H3D. It would be nice to have multi AF points but we do what we can!
....and for those reasons I would not say that Phase One and Hasselblad are creating somewhat equivalent products.
Best,
David
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David, so a dead on AF but no solution for manual focussing?
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Bernard, we are not being belligerent in not offering this feature. It is simply not available (yet) at sensor level. Of course, if it were possible we would use it!
Just because a medium format system doesn't have live view does not then render it impossible to focus. That is a rather naive attitude.
David,
Sure, using the back on a body offering AF capability like the h3d helps if it accurately calibrated, but the focus () of the current post was about using a back on a LF like camera.
Cheers,
Bernard
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I migrated from a Mamiya AFD to a Hassey H2F primarily for the improvement in AF. The difference is dramatic, especially in low light situations. Of course AF on the H platform isn't as fast as it is on Canons and Nikons; it's stupid to compare apples to oranges. The H platform may have its flaws, but all things considered, it's a great camera.
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David, so a dead on AF but no solution for manual focussing?
If using the H3D focus confirmation in the form of information in the viewfinder is still active.
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I am quite new to this forum, but so tired about this Hasselblad discussions in almost every thread I read. Could someone consider to give these issues a dedicated subforum so that all the other users can find relevant information on the topics they originally wanted to learn about?
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If using the H3D focus confirmation in the form of information in the viewfinder is still active.
see also: If the D3x says it is sharp - and the Dot appears - I can make within the room of the dot six pictures - only one is truly sharp. If i use auto focus at near infinity with lots of small detail the auto focus is near but not accurate...
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I am quite new to this forum, but so tired about this Hasselblad discussions in almost every thread I read. Could someone consider to give these issues a dedicated subforum so that all the other users can find relevant information on the topics they originally wanted to learn about?
Maybe you should get used to hearing Hasselblad or Phase in virtually every thread since they are basically the only 2 remaining 'Large Sensor capture device' (I believe we are not allowed to call them MFDB's anymore) manufacturers
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Is the "Live Video" function in Phocus useful for critical focusing?
Steve
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Is the "Live Video" function in Phocus useful for critical focusing?
Steve
Very much so, especially as you can control the focussing remotely as well without having to touch the camera.
It takes a bit of care setting up, as Live Video works best in lower light so you can open the aperture fully to make focussing easier.
Entering live video automatically raises the mirror and then from Phocus you can control the aperture for optimum results. When leaving live video the aperture is reset to the capture value.
Hope that helps!
D
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Very much so, especially as you can control the focussing remotely as well without having to touch the camera.
It takes a bit of care setting up, as Live Video works best in lower light so you can open the aperture fully to make focussing easier.
Entering live video automatically raises the mirror and then from Phocus you can control the aperture for optimum results. When leaving live video the aperture is reset to the capture value.
Hope that helps!
D
Hi David.
And when are you going to make that available on the H3D-50? The camera is sold since last year....
(could it be that you missed this question in Dick's and my repeated posts?)
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Live view in Phocus is useful especially being able to adjust autofocus in increments in Phocus itself for the H3D
However, Live View is also very light sensitive and does not work properly in daylight (slightly cloudy day)
So just take note that if you're going to use it on a technical camera for landscapes you need to put on some strong ND filter
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My experience with the D3x is that AF is very good, but the focus adjustment varies with the focus distance and over time.
At F:4 I consistently get nice images with whatever lens I use or subject. Anything below that and front or backfocus becomes perceptible from time to time; it's not really the fault of the camera, apparently, just inconsistencies of the measurement method. On a ruler test I'll get a focus difference of less than 1cm at 1 meter; not a lot but enough to throw off an eye at F1.4. On a distant object again there is a slight focus issue, but this time it'll go the other way ... In the end the only thing one can do is grin and accept that 2009 technology has limits.
Edmund
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Thanks for the review, and sorry to take this off the focus issues, but one little question... what's the deal on this camera actually shipping?
...guess I'm getting jaded, but is this just really nice, expensive vaporware?
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The camera is shipping. As of July '09 the E-Module is not yet.
Michael
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Interesting review. The Rm3d takes some novel approaches to aid focusing with the E-module, but it still seems pretty kludgy (especially using ultrasonic distance measurement instead of laser). I definitely agree with Bernard that LiveView is really the ultimate solution, it's just a matter of when the MF guys will be able to deliver it. Until you've used LiveView on the D3/D3x you just can't imagine how good it is for critical focusing with both autofocus and manual focus lenses. In fact I'm thinking that the F-Line 2 plus a D3x would be a better solution for me than the Rm3d with entry-level digital back for this very reason. I just wish there was more info available on the F-Line 2, particularly any limitations/gotchas when using the DSLR version (lens compatibility, etc).