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Author Topic: Can you see a difference in small prints between an MFDB and a DSLR?  (Read 36952 times)

ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #20 on: February 27, 2014, 05:24:33 PM »

Hi,

SQF is not related to MP but to MTF of the sensor and the lens. It is calculated from the MTF integrated (summed) over the angular sensivity of the eye.

So you need to measure the MTF of the lens, camera and conversion chain. I would calculate the MTF of the IQ-250 if I had a shot of a slanted edge.

MTF is much affected by sharpening, I used the same sharpening on both images. I did the test with an IQ-180 and that would give an SQF around 98, visibly better than either the Pentax 645D or the Sony.

The IQ-180 image was coming from Tim Parkin.

Sharpening is a real joker in the context. I should have mentioned it before.

Best regards
Erik


http://www.imatest.com/docs/sqf/

What is the sqf rating of the IQ250/260 shots in imatest?

What is the correlation of MP to print size? Your 24MP gives you a 90 at 17" diagonal, what about 16MP (90), 36MP (90)?

synn

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #21 on: February 27, 2014, 05:36:49 PM »

:-) maybe. maybe not. I don't know. I don't care about those comparision tools.
What I do know is that this forum is completely polluted with too much theoretical talk (scientific and pseudo scientific talk). In every thread I get explained that my DBs show aliasing, moire and pseudo details (as f I wouldn't know it...). 2 posts later someone talks about AA filters and deconvultion sharpening. In the third post a completely unexperienced user finds out that C1 doesn't produce accurate colors (based on a color checker passport shot with mixed lights). In the 5th post someone is talking about skin tones although he never shoots people. But he is finding flowers and/or animal hair compares quite good to skin. And in the 6th post we talk about the D800 or D800E or the A7R.
In EVERY thread, 3 times a day.
That's all fine... but it gets really, really old. Not a particular issue is getting old... but the way and the style things get discussed here. Erik invested 15K just to be able to talk about MFD. Now, this is an issue that should be treated seriously... I really think he needs professional help. But, please, let's not discuss this on this forum...
Bart, sorry, maybe the method implemented in the said SQF thing is great. But I simply don't care (anymore).


I remember the animal hair skin tone post. One of the most hilarious things I have ever seen on the internet.

@Erik: I sincerely hope that some day, you will ask yourself " why are other people shooting better  images than me with better AND worse gear.

Unfortunately,there is no lab test in the world that can answer that question.
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Wayne Fox

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #22 on: February 27, 2014, 05:43:30 PM »

Erik, if your experience is essentially that you see no difference between your P45+ and your Sony SLT99 in A2 size prints then use your Sony for the A2 prints and your P45+ for your larger prints.

certainly logical ... but I rarely know when shooting when those cases will be.  So I must always assume I will be wanting to make a big print...
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Joe Towner

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #23 on: February 27, 2014, 05:45:45 PM »

To make it simple, it depends on what you call a 'small print'.  Then you toss in what printer you're dealing with, and what paper/material you're printing on.  Top it off with the viewing environment and the viewing distance, and there are lots of variables.  Then you have the person viewing the image, what level of detail can they discern, and how is their eyes' color spectrum.  Too many variables, too much thinking.

Take the same question at the paper size (16.5 x 23.4 in) and do it just in DSLR's and compare crop to full frame.  Can you tell a difference?  It comes down to you, the observer.

MFD won't shine as much in smaller sizes, but the bigger the print, the bigger the improvement.
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Paul2660

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #24 on: February 27, 2014, 05:53:29 PM »

certainly logical ... but I rarely know when shooting when those cases will be.  So I must always assume I will be wanting to make a big print...


+1, that states it very well.

Paul C.
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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 #25 on: February 27, 2014, 06:02:49 PM »

certainly logical ... but I rarely know when shooting when those cases will be.  So I must always assume I will be wanting to make a big print...
herewith you are indirectly saying you don't know what you shoot.
Think while you shoot. Have a plan. Have a concept. (Also a concept of presentation.) Never (never!) take snapshots.
Sometimes I go "shooting" (2, 3, 4 days tours...) and don't even take the camera out of my case at all because the respective motifs are not worth shooting ...
Photography is not about touching or handling the gear and pressing knobs... it is about the final image. It is about vision.
« Last Edit: February 27, 2014, 06:06:44 PM 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 #26 on: February 27, 2014, 06:10:02 PM »

Hi

This was the original post, and I feel it deserves an honest answer. I interpreted the question as a resolution thing, and I have really found that most of my cameras were good enough for A2. I also did some extra checking with Bart van der Bart's tool and checked the Bruce Fraser/Jeff Schewe book and also measured SQF on two samples.

Regarding the colour question I cannot say much, as I don't own a Nikon and don't shoot portraits, but colour does not relate to print size.

Best regards
Erik





To make it simple, it depends on what you call a 'small print'.  Then you toss in what printer you're dealing with, and what paper/material you're printing on.  Top it off with the viewing environment and the viewing distance, and there are lots of variables.  Then you have the person viewing the image, what level of detail can they discern, and how is their eyes' color spectrum.  Too many variables, too much thinking.

Take the same question at the paper size (16.5 x 23.4 in) and do it just in DSLR's and compare crop to full frame.  Can you tell a difference?  It comes down to you, the observer.

MFD won't shine as much in smaller sizes, but the bigger the print, the bigger the improvement.

Fine_Art

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #27 on: February 27, 2014, 07:04:47 PM »

Hi,

SQF is not related to MP but to MTF of the sensor and the lens. It is calculated from the MTF integrated (summed) over the angular sensivity of the eye.

So you need to measure the MTF of the lens, camera and conversion chain. I would calculate the MTF of the IQ-250 if I had a shot of a slanted edge.

MTF is much affected by sharpening, I used the same sharpening on both images. I did the test with an IQ-180 and that would give an SQF around 98, visibly better than either the Pentax 645D or the Sony.

The IQ-180 image was coming from Tim Parkin.

Sharpening is a real joker in the context. I should have mentioned it before.

Best regards
Erik



That is why I used the word correlation. I do not expect a precise function.

Personally I find Super B (13x19 in) is good from a 16-24MP camera. Consumers can usually get that size printer and paper easily.
If I want a shot to frame in C or D size I expect to stitch 2x2 or 3x3 shots.



I bet people bitching about the thread would not be out shooting every day either if they lived as far north as Erik.
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BernardLanguillier

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #28 on: February 27, 2014, 07:30:56 PM »

Photography is not about touching or handling the gear and pressing knobs... it is about the final image. It is about vision.

Exactly, the camera is clearly the least important thing in photography (and I totally mean this).

But these threads are not about photography, they are about cameras.  ;)

The good news is that it is totally possible for one person to be interested in both subjects since they happen to be vaguely related.  ;D

Cheers,
Bernard
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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 #29 on: February 27, 2014, 07:31:59 PM »

I once compared the same pastry made by two different chefs by reading up the recipe. I even used prescription glasses.

They tasted the same to me.
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BernardLanguillier

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #30 on: February 27, 2014, 07:33:50 PM »

I once compared the same pastry made by two different chefs by reading up the recipe. I even used prescription glasses.

They tasted the same to me.

Wrong analogy. You should have said that you tasted the lab analysis results.

Please concentrate!  ;)

Cheers,
Bernard
« Last Edit: February 27, 2014, 07:41:12 PM by BernardLanguillier »
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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 #31 on: February 27, 2014, 10:57:09 PM »

Wrong analogy. You should have said that you tasted the lab analysis results.

Please concentrate!  ;)

Cheers,
Bernard


Indeed, that's what I tasted.
...and both of them were awful and therefore, every pastry in the world must be the same.
« Last Edit: February 28, 2014, 01:22:58 AM by synn »
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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 #32 on: February 28, 2014, 01:32:39 AM »

Hi,

Some folks would say that 12 or 25 MP is enough. The folks at Outbackphoto used to say that 12 MP is enough, I don't know if it is still their opinion. The reasoning is that larger print sizes are normally viewed at a longer distance.

My experience is that 12 MP was quite enough for A2 size prints. I found this out when I started looking at 24MP full frame compared to 12 MP MPS-C. The files from the 24 MP camera were much better, but the difference in A2 size prints was very small. Bruce and Jeff's book mention 180 PPI as a reasonable limit and my 12 MP camera would give 16.8" on the short dimension at 180PPI. The 180 PPI is based on 20/20 vision at 50 cm / 20 inches. Once you get to the 180PPI limit resolution plays a lesser role and fine detail contrast dominates, which is much effected by sharpening.

A couple of years ago I found an autumn subject I really liked. The problem I had was that it was windy, and I was quite concerned about subject motion. I initially tried with my Sony Alpha 900 but figured I could use the SLT 55 I also had at the time. The SLT would allow me to use a shorter lens, focus accurately, open up one more stop and use an EV step higher ISO.

I ended up with printing both images in A2, it was the 16 MP image that made on to the wall, but they very pretty close.

I think this discussion is meaningful, the OP was really asking if he would gain benefits with MF stating that he prints mostly A3 and up to A2 (if I recall correctly).

Best regards
Erik





That is why I used the word correlation. I do not expect a precise function.

Personally I find Super B (13x19 in) is good from a 16-24MP camera. Consumers can usually get that size printer and paper easily.
If I want a shot to frame in C or D size I expect to stitch 2x2 or 3x3 shots.



I bet people bitching about the thread would not be out shooting every day either if they lived as far north as Erik.

ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #33 on: February 28, 2014, 04:03:43 AM »

Hi,

That is what I do now, I mostly carry a dual kit, but most shooting is with the P45+, I actually enjoy it.

But this thread was started to give a good response from some one making A3 up to A2 size prints and asking if there was a a gain at that size.

Best regards
Erik



05:44 PM

Erik, that's a persuasive argument for using your P45+ wherever possible.

leeonmaui

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #34 on: February 28, 2014, 08:48:21 PM »

Aloha,

I think after about 40 inches getting solid prints from 35mm is a crap shoot, and depends a lot on how perfect the shot was and the subject matter, I also think a lot of the problems from big 35mm prints comes from lens choice. But again I think sometimes you can get really nice big prints from 35mm

I don't shoot 35mm anymore, I do tons of printing but all to developed film using lightjet, this in itself probably makes big 35mm prints seem nicer, but everything I shoot now has the potential to be done as a big print, so I don't risk shooting 35mm.

I also feel the quality of the gear in MF to be much better than 35mm and a lot of the lenses superior in every way.
I think in the print size of 36 to 72 inches MF will just shine against 35mm in a more consistent manor, in that more of your shoots will look great big.

After 72 inches I don't know how even MF will hold up when examined critically, as you are starting to up sample a lot by then, and things start to smooth out, a couple of my friends start to add noise on really big prints to counter balance this.

I guess there are so many variables depending on camera, subject, post work, etc...         
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eronald

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #35 on: February 28, 2014, 10:20:55 PM »

I remember the animal hair skin tone post. One of the most hilarious things I have ever seen on the internet.

@Erik: I sincerely hope that some day, you will ask yourself " why are other people shooting better  images than me with better AND worse gear.

Erik,

 I am sorry you are on the receiving end of these comments. Kindergarten behavior.

Edmund
« Last Edit: February 28, 2014, 10:54:42 PM by eronald »
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Fine_Art

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #36 on: February 28, 2014, 11:52:54 PM »

Hi,

Some folks would say that 12 or 25 MP is enough. The folks at Outbackphoto used to say that 12 MP is enough, I don't know if it is still their opinion. The reasoning is that larger print sizes are normally viewed at a longer distance.

My experience is that 12 MP was quite enough for A2 size prints. I found this out when I started looking at 24MP full frame compared to 12 MP MPS-C. The files from the 24 MP camera were much better, but the difference in A2 size prints was very small. Bruce and Jeff's book mention 180 PPI as a reasonable limit and my 12 MP camera would give 16.8" on the short dimension at 180PPI. The 180 PPI is based on 20/20 vision at 50 cm / 20 inches. Once you get to the 180PPI limit resolution plays a lesser role and fine detail contrast dominates, which is much effected by sharpening.


That may be A logic, it is not what I do. If I see a nice image in a gallery I position to a normal viewing distance, take in the whole thing, if I like it I will lean in or move closer. If it still has quality detail I will be impressed. If it does not I will be disappointed.

Only images that survive impressing someone may get bought.
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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 #37 on: March 01, 2014, 01:09:57 AM »

Same here,

Still I feel it is a bit amazing how well small MP often holds up.

Also, I actually think it depends on subject. If the subject doesn't have unresolved detail it may be that sharpening plays a larger role.

Personally I am in favour of high resolution (small pixels), as I find it can reproduce fine detail, but the question is how much is visible in print.

Best regards
Erik




That may be A logic, it is not what I do. If I see a nice image in a gallery I position to a normal viewing distance, take in the whole thing, if I like it I will lean in or move closer. If it still has quality detail I will be impressed. If it does not I will be disappointed.

Only images that survive impressing someone may get bought.

ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #38 on: March 01, 2014, 02:04:56 AM »

Hi,

I can live with that. If you post on a listing you can always count on having some bad comments.

Synn and some other posters have a view missing out the fact that many of the posters on these forums are not portrait shooting professionals. Many are amateurs and many are landscape shooters. So many aspects important for professionals is not very important for many readers who may be landscape shooters and shooting in their free time. Quite a few are not flush with money.

The OP (the posting was on another thread) has migrated from MF/LF film to digital. He was printing in small to moderate sizes like A3 and A2, not larger. The question he asked if MFD would give a visual advantage at those sizes. From what I have seen, I am a bit skeptical, as I have printed files with very different MP (and vastly different on screen at 1:1) and not being able to tell them apart in print at A2-size. I have tested those images on quite few persons but now one could tell them apart.

I have done quite a few test like this and it seem that if processing is equal, little difference may be visible, specially if the subject does not have very fine detail. It is more down to sharpening and that can be varied quite a lot.

Best regards
Erik




Erik,

 I am sorry you are on the receiving end of these comments. Kindergarten behavior.

Edmund

ErikKaffehr

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Re: Can you see a difference in small prints between an MFDB and a DSLR?
« Reply #39 on: March 01, 2014, 03:22:39 AM »

Hi,

You can get very different SQF depending on sharpening. I used my standard sharpening for both images, see below. It is easy to add some additional sharpening like amount 15 and radius 3 to those images, that would push SQF comfortably above 100 on both lenses. Still I am pretty sure that if you apply same sharpening to the processed images you would get pretty close result in small prints.

I would love to publish SQF with better sharpening, but my first experiments today went into what I consider oversharpening, so I need more work before I can share.


The Pentax image was this one: http://www.imaging-resource.com/PRODS/645D/645DhRES7264F.DNG.HTM

The Pentax was at slight advantage here, by the way. It has a very recent 75/2.8 lens at f/5.6, while my lens in the sample I posted was a 20 year old Minolta Macro 100/2.8 at f/8 which is not it's best aperture.  I will do some more testing and repost, but I am quite sure that:

- If you use same processing the SQF values will be pretty close (within 5%) for low end MF and high end DSLRs
- If you use use different processing you can get almost any SQF you want

Best regards
Erik






Erik,
I needed to work more with my Mac Beta version of Imatest and I have taken test images with most all of the lenses in Rollei 6000/Hy6 mount so I ran some of them through to look at SQF numbers.

First of all, as I mentioned there are quite a lot of variables that influence SQF results - so YMMV.   There's the lens of course, then the aperture, then the region of interest chosen (center or edge), then capture level sharpening if used, noise reduction,

My recollection was most of the Rollei lenses scored in the high end, but I didn't realize that they were as high as they were.   I'm looking at the AF 80mm Xenotar lens for Rollei 6000/Hy6 @ f/8 data now.  Every point in the frame is scoring over 98 at a picture height of 40cm and most of the center is over 99.   I'm attaching one chart from a test point on the very left edge just for reference which reads almost 99 at picture height of 40cm.  The center points are all ranging from 99.8 to 99.3
  
Erik - Hopefully from this actual test datum - you'll begin to understand why I have always felt you could be getting more from your MFDB.  It's true that the Rollei lenses are quite excellent, but I believe that even your older Hasseblad should be capable of more than you have shown.  

Please refrain from asking me to supply you RAW files for your own enjoyment.  At some time this year I will be publishing comprehensive lens test data on all the Rollei lenses for Hy6 and 6000 series cameras.

I have no idea where you got your SQF numbers for your Pentax 645D and other cameras but you should really check to make sure what parameters were used so that the can be compared fairly in this hypothetical test of yours.  And as pointed out - if the question is whether a person could see a difference in a print, then actually using real prints is probably the best approach.


 



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