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Author Topic: Can you see a difference in small prints between an MFDB and a DSLR?  (Read 79465 times)

Fine_Art

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #180 on: March 07, 2014, 04:22:22 pm »

Maybe their sendspace accelerator is infected, my file is not. I use 2 top rated AV programs to scan my PC. Webroot and bitdefender.
Uncheck their download accelerator box.

A nef is not an executable.

100% crop Sharpening off, Contrast by detail off.
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EricWHiss

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #181 on: March 07, 2014, 11:18:11 pm »


1) The main issue with the Planar is field curvature. The focal plane is curved but the lens will be sharp in the areas that have focus.


I thought they called it Planar for a reason….
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #182 on: March 07, 2014, 11:19:44 pm »

Actually, I am also pretty sure the lens is pretty OK.

Regarding test charts, I actually feel that they have a lot of advantages. Most test targets are designed to do one or two things at do it well. Also any experiment with test charts can be easily reproduced. That is in part the reason I use a one Dollar bill. It is widely available.

There is also an advantage with shooting some kind of setup, I can go back and reshoot easily.

Best regards
Erik

But you don't know that it is a lens issue. I think it is not a lens issue.



I did not write that you only shoot test charts, just that you shoot lots of them ;)
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #183 on: March 08, 2014, 12:10:59 am »

Hi,

The reason they call it Planar is that it is a double gauss design and the reason they call it Makro Planar is that it is corrected short focusing distances.

Zeiss call their double gauss lenses Planars. One problem with most designs is the field curvature varies with focusing distance. Building a lens that has flat field over a wide range of focusing distances needs a floating element design, that is a group of elements that moves with focusing (according to Hubert Gauss of Zeiss). Some of the Zeiss Distagons have an extra focusing ring for the floating element. Those lenses have FLE designation.

The Makro Planar is designed for close up work. The Zeiss spec sheet http://www.hasselbladhistorical.eu/pdf/lds/CFi120.pdf shows the MTF curves for both close range (1:4 magnification) and infinity, see below.

Still the Makro Planar is usable for general photography, but it needs to be stopped to f/11 (or even f/16) to make sharp photographs of flat subjects. The lens will always be sharp at the point of focus, but shooting a brick wall is not a good way to test this lens.

If you want to learn more about field curvature here is a very nice article: http://tashley1.zenfolio.com/blog/2013/5/field-curvature---a-practical-guide

Another interesting article is the one below Hubert Nasse of Zeiss,  Makro lenses are discussed on pages 8-12

http://blogs.zeiss.com/photo/en/wp-content/uploads/2011/07/en_CLB_40_Nasse_Lens_Names_Planar.pdf

As a curiosity, the article by Hubert Nasse ends with a banknote shot, showing a portrait of Friedrich Gauss.

Best regards
Erik



I thought they called it Planar for a reason….
« Last Edit: March 08, 2014, 12:31:26 am by ErikKaffehr »
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jerome_m

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #184 on: March 08, 2014, 02:07:39 am »

Actually, I am also pretty sure the lens is pretty OK.

From the examination of the file "Fischleinboden" at the bottom of that page: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/80-my-mfd-journey-summing-up?start=6, I think that the problem is that your camera has lots of noise in dark areas. On the iiq, you will need to use it without noise reduction to see it (and that is not easy unless using a non-commercial derawtiser). On the jpeg, this translate to the dark areas looking mudded and unsharp from the noise reduction (under the pines and the wooden house).
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #185 on: March 08, 2014, 03:16:35 am »

Hi,

Thanks, I can check with RawDigger (I think), or DC-raw. I rutinely use RawDigger to check exposures, it is a learning experience.

But, I don't think is the issue in this case as the subject has not very high contrast and it was exposed pretty much to the right. I don't think focusing is an issue either, as the depth of focus is shallow, so it is just about to look for a place which is in focus. My hunch is that aliasing may be the root of the problem. There is a lot of colour aliasing, and that essentially means that the lens outresolves the sensor.

It is very visible in the included crops.

I actually don't know what the problem is, but I got the impression that Bart says that the image doesn't sharpen well.

I made a small experiment, the second example here, it is a central crop from the image developed in Capture One with default sharpening and Focus Magic (out of focus, auto detect) on a separate layer. The FM layer is mostly masked out except in the marked areas. The out of focus areas sharpen nicely in FM but the in focus areas just fall apart. This is pretty much what I have seen in Synn's sharpening. In real world sharpening I guess I would apply FM with more finesse.

It would be interesting to reshoot the image with f/16 which seems to eliminate most aliasing.

Best regards
Erik

From the examination of the file "Fischleinboden" at the bottom of that page: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/80-my-mfd-journey-summing-up?start=6, I think that the problem is that your camera has lots of noise in dark areas. On the iiq, you will need to use it without noise reduction to see it (and that is not easy unless using a non-commercial derawtiser). On the jpeg, this translate to the dark areas looking mudded and unsharp from the noise reduction (under the pines and the wooden house).
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EricWHiss

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #186 on: March 08, 2014, 04:57:59 am »

Erik,
You get high marks for answering a question I didn't ask.  But you missed my point completely.     Hope you didn't spend to much time on it. 
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synn

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #187 on: March 08, 2014, 05:02:45 am »

I almost thought we were making some progress with this thread, but it seems like we are back to square one.
Oh well, graph lovers rejoice!
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tho_mas

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #188 on: March 08, 2014, 05:43:36 am »

Quote
From the examination of the file "Fischleinboden" at the bottom of that page...
I don't think focusing is an issue either, as the depth of focus is shallow, so it is just about to look for a place which is in focus. My hunch is that aliasing may be the root of the problem. There is a lot of colour aliasing, and that essentially means that the lens outresolves the sensor.
Are you talking about to the "Fischleinboden" image Jerome was referring to? IMO the image clearly shows front focus and I can't see any color aliasing either ...

It would be interesting to reshoot the image with f/16 which seems to eliminate most aliasing.
You can eliminate aliasing once and forever by shooting your Sony A99. Easy fix.
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #189 on: March 08, 2014, 06:09:44 am »

Hi

Your posting:
Quote
thought they called it Planar for a reason….
could be interpreted like you are not well informed on Planars and Makro Planars. What would your point be? If you think that Makro Planars (the MF lenses) have planar field than you are obviously wrong. If you are familiar with the lens, your statement is absolutely pointless.

The papers by Hubert Nasse on Zeiss lenses are an interesting read.

Best regards
Erik
Erik,
You get high marks for answering a question I didn't ask.  But you missed my point completely.     Hope you didn't spend to much time on it.  

« Last Edit: March 08, 2014, 06:11:30 am by ErikKaffehr »
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #190 on: March 08, 2014, 06:23:48 am »

Nope , the original image. Bart says it doesn't sharpen well. Not very clear why, but my understanding is he feels the image falls apart in sharpening.

Bart, like me noted significant colour aliasing in the image when processed in LR 5.3, that colour aliasing doesn't show up in C1, but my guess is that it is still around in it's monochrome form and can create fake detail.

The Sony A99 also has aliasing but OLP filter reduces colour aliasing. There is plenty of monochrome aliasing on the A99. I guess it takes around 3 my pixels to get rid of aliasing entirely at f/8. On the P45+ it takes f/16. With f/11 theres is plenty and at f/16 it is almost entirely gone.

Best regards
Erik



Are you talking about to the "Fischleinboden" image Jerome was referring to? IMO the image clearly shows front focus and I can't see any color aliasing either ...
You can eliminate aliasing once and forever by shooting your Sony A99. Easy fix.
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tho_mas

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #191 on: March 08, 2014, 06:46:20 am »

The main issue with the Planar is field curvature. The focal plane is curved but the lens will be sharp in the areas that have focus.
Contax Planar 2.0/80 at f11 (on P45). Background = crop of the top left edge from the processed TIF which already includes distortion correction (so some degradation due to interpolation).
This is medium distance, but the lens performs the same at wide distances.
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tho_mas

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #192 on: March 08, 2014, 06:49:29 am »

Nope , the original image.
so you've replied to Jerome without replying to him. Hmh...

Bart says it doesn't sharpen well. Not very clear why, but my understanding is he feels the image falls apart in sharpening.
maybe you can post the original IIQ file and not a damn DNG.
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Bart_van_der_Wolf

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #193 on: March 08, 2014, 07:39:23 am »

Nope , the original image. Bart says it doesn't sharpen well. Not very clear why, but my understanding is he feels the image falls apart in sharpening.

Hi Erik,

That's correct. Proper (deconvolution) sharpening procedures restore resolution, but they do require a reasonably close resembling PSF to do their blur reversal while retaining a natural/organic look.

No matter what I tried (so far) on the moss images, it didn't restore a natural looking transition from blur to sharpness. Part of the explanation may be that the aliased pixel sharpness dominates the blur to a degree that it becomes objectionably visible as block artifacts (stair-stepping) before real blur is even removed. Trying to completely (as far as present in the optical image, i.e. lens + sensor) restore sharpness will exaggerate the stairstepping artifacts too much.

So we seem to have a somewhat blurry optical image, and a sharper stair-stepping artifacting that prevents optimal deblurring in a single operation. Had the lens been sharper, there would be less of a difference between the inherent blur and the sharp artifacts, and less sharpening could lift the total image resolution without too much artifact 'enhancement'.

Maybe, but that needs to be tested further, there is sort of a solution possible in the sense of adding an additional very small radius blur before doing the deconvolution of the real larger radius lens blur. That very small radius blur would take the 'edge' of the stair-stepping and take that detail level down a bit, closer to the real lens blur. Then a subsequent deconvolution of the real lens blur will not exaggerate the stair-stepping as much, and real lens resolution can be restored more.

Quote
Bart, like me noted significant colour aliasing in the image when processed in LR 5.3, that colour aliasing doesn't show up in C1, but my guess is that it is still around in it's monochrome form and can create fake detail.

It's not just the false color artifacting (which is more Bayer CFA related, and usually repairs relatively well), but also a more subtle treatment of aliasing that was introduced with the Capture One 7 engine. I also noticed it in images with my 1Ds3 which, despite the AA-filter, is still capable of aliasing and stair-stepping, but less so with Capture One 7.

Cheers,
Bart
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #194 on: March 08, 2014, 07:42:58 am »

Hi,

Something you may have missed that we are discussing the Zeiss 120 Makro Planar which is a entirely different lens. The Makro planar is intended for close range, but it works well at infinity if stopped down.

Sonnar 150/4 Makro Planar 120/4
f/5.6
f/11

The right column is the Makro Planar 120/4. At f/4 focus something like 20 meter in front of the building (visible on grass), these crops are from the right edge of the shot. As you see the lens Makro Planar sharpens up nicely at f/11.

If you look at Zeiss MTF data at infinity you see that edge MTF is very low:


But at close up range it improves significantly, because field curvature gets small:


Best regards
Erik


Contax Planar 2.0/80 at f11 (on P45). Background = crop of the top left edge from the processed TIF which already includes distortion correction (so some degradation due to interpolation).
This is medium distance, but the lens performs the same at wide distances.

« Last Edit: March 08, 2014, 08:01:43 am by ErikKaffehr »
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Bart_van_der_Wolf

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #195 on: March 08, 2014, 07:57:40 am »

maybe you can post the original IIQ file and not a damn DNG.

That would indeed remove yet another unknown influence from the equation. I'd like to try my hypothesis of very small radius pre-blur (to reduce extremely high spatial frequency stairstepping) on a straight C1 v7 conversion without sharpening and without noise reduction, but with linear response tonecurve. It would help to eliminate the potentially detrimental DNG conversion for now.

I'm not sure yet if a pre-blur of the order of 0.37 radius is optimal, and it could be interesting to also test Topaz Labs DeJPEG plugin, which allows to reduce JPEG blocking artifacts, maybe it also works on single pixel block boundaries. Also worthwhile may be to compare against Topaz Labs InFocus with its automatic PSF Estimation with edge smoothing, maybe it picks up the correct/mixed PSFs and allows to reduce the stairstepping from dominating.

I understand Sandeep's sentiments, but without a real effort, Erik will remain to have a somewhat unsatisfied feeling when he inspects his images (I know I would). Others may also learn something for their own benefit along the way ...

Once that is cleared up, we can do a true comparison between small prints, although that will still be limited by viewing distance and inherent (but now optimal) image resolution.
 
Cheers,
Bart

P.S. Getting a handle on stair-stepping suppression when sharpening may also help the images from other cameras without OLPF, such as Sigma Foveon designs, D800E, Sony A7r, Pentax K3, other MFDBs, etc...
« Last Edit: March 08, 2014, 08:12:44 am by BartvanderWolf »
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tho_mas

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #196 on: March 08, 2014, 08:00:47 am »

Something you may have missed that we are discussing the Zeiss 120 Makro Planar
Contax Apo Makro Planar 4/120 at f8 (on P45).
Background = 100% crops from the processed TIF (including perspective correction/straightening... so again some degradation due to interpolation). Image was intentionally focussed to get the grass as soft as possible while getting the building as sharp as possible at the same time.
Note the moiré of the ventilator at the edge of the image. Again no field of curvature to speak of in practice.
« Last Edit: March 08, 2014, 08:10:53 am by tho_mas »
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #197 on: March 08, 2014, 08:19:35 am »

Hi,

What you miss is the Contax Apo Makro Planar is a different lens. Among other things it has 8 lens element and the Hasselblad 120/4 Makro Planar has 6 elements. I also checked, the Apo Macro has floating element (FLE) design.

So know you are better informed. OK?

Actually, I have been told that all 120/4 lens groups were identical designs, but that is obviously wrong. Nice for you to have an excellent general purpose lens.

Best regards
Erik

http://www.zeissimages.com/mtf/645/Apo-Makro-Planar4_120mm_e.pdf
http://www.hasselbladhistorical.eu/pdf/lds/CFi120.pdf



Contax Apo Makro Planar 4/120 at f8 (on P45).
Background = 100% crops from the processed TIF (so again some degradation due to interpolation). Image was intentioanlly focussed to get the grass as soft as possible while getting the building as sharp as possible at the same time.
Note the moiré of the ventilator at the edge of the image. Again no field of curvature to speak of in practice.

« Last Edit: March 08, 2014, 08:32:54 am by ErikKaffehr »
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #198 on: March 08, 2014, 08:45:05 am »

Hi Bart,

The raw images are here: http://echophoto.dnsalias.net/ekr/Articles/PrintSize2/RawImages/

The DNG files actually contain bitwise binary copies of the raw images.

I much appreciate your efforts, and I must say I am very much interested about what you find out.

Best regards
Erik


That would indeed remove yet another unknown influence from the equation. I'd like to try my hypothesis of very small radius pre-blur (to reduce extremely high spatial frequency stairstepping) on a straight C1 v7 conversion without sharpening and without noise reduction, but with linear response tonecurve. It would help to eliminate the potentially detrimental DNG conversion for now.

I'm not sure yet if a pre-blur of the order of 0.37 radius is optimal, and it could be interesting to also test Topaz Labs DeJPEG plugin, which allows to reduce JPEG blocking artifacts, maybe it also works on single pixel block boundaries. Also worthwhile may be to compare against Topaz Labs InFocus with its automatic PSF Estimation with edge smoothing, maybe it picks up the correct/mixed PSFs and allows to reduce the stairstepping from dominating.

I understand Sandeep's sentiments, but without a real effort, Erik will remain to have a somewhat unsatisfied feeling when he inspects his images (I know I would). Others may also learn something for their own benefit along the way ...

Once that is cleared up, we can do a true comparison between small prints, although that will still be limited by viewing distance and inherent (but now optimal) image resolution.
 
Cheers,
Bart

P.S. Getting a handle on stair-stepping suppression when sharpening may also help the images from other cameras without OLPF, such as Sigma Foveon designs, D800E, Sony A7r, Pentax K3, other MFDBs, etc...
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ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #199 on: March 08, 2014, 08:54:54 am »

Hi,

Here are all images: http://echophoto.dnsalias.net/ekr/Articles/PrintSize2/RawImages/index.html

The DNG images contain a bitwise copy the raw image. But I have put the raw images on the server, too.

I was actually answering Jeremy. He suggested that the problem was noise in shadow detail, due to noisy sensor. I said I didn't think so and suggested that aliasing may be the cause.

Best regards
Erik



That would indeed remove yet another unknown influence from the equation. I'd like to try my hypothesis of very small radius pre-blur (to reduce extremely high spatial frequency stairstepping) on a straight C1 v7 conversion without sharpening and without noise reduction, but with linear response tonecurve. It would help to eliminate the potentially detrimental DNG conversion for now.

I'm not sure yet if a pre-blur of the order of 0.37 radius is optimal, and it could be interesting to also test Topaz Labs DeJPEG plugin, which allows to reduce JPEG blocking artifacts, maybe it also works on single pixel block boundaries. Also worthwhile may be to compare against Topaz Labs InFocus with its automatic PSF Estimation with edge smoothing, maybe it picks up the correct/mixed PSFs and allows to reduce the stairstepping from dominating.

I understand Sandeep's sentiments, but without a real effort, Erik will remain to have a somewhat unsatisfied feeling when he inspects his images (I know I would). Others may also learn something for their own benefit along the way ...

Once that is cleared up, we can do a true comparison between small prints, although that will still be limited by viewing distance and inherent (but now optimal) image resolution.
 
Cheers,
Bart

P.S. Getting a handle on stair-stepping suppression when sharpening may also help the images from other cameras without OLPF, such as Sigma Foveon designs, D800E, Sony A7r, Pentax K3, other MFDBs, etc...
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