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Take the highest MP count you can get....or

Annna T

Active member
Hi,


But, there is another axis, and that is sharpening. With good sharpening MTF can be regained but resolution cannot be regained.

Tim Parkin, the publisher of OnLandscape has looked into this in some detail, and he found that he could get better fine detail from a Nikon D800 he tested at f/22 than from his Sony Alpha 900 at f/8, with adequate sharpening.

I must say, I have not been able to reproduce his results with the gear I had that time.

Best regards
Erik
Then I wish I were a better sharpener ! I have read Bruce Fraser's book on sharpening, not skipping a single page, but I still feel that I don't master it.
 

dandrewk

New member
Then I wish I were a better sharpener ! I have read Bruce Fraser's book on sharpening, not skipping a single page, but I still feel that I don't master it.
It's not an easy thing to master, especially since it is very different for every shot.

I've recently put my trust into OnOne's filter set, which includes a whole parcel of sharpening options. Much more often than not, the defaults work great.

 

dandrewk

New member
The right image looks over-sharpened to me. I see zigzags and jaggies. Sorry.
Yes, you are correct. That's what I get for grabbing a random screen capture from Google. But it's the only one I could find, and used it for illustration. This is also a highly compressed .png image from the screen capture, the underlying image already magnified well over 1:1.

BTW, I never use "progressive" nor go to 100% (and doubtful I'd ever sharpen a portrait). I'd show you what I mean, but this is the wrong thread.
 

jerome_m

Member
Guy mentioned if two cameras were on a table he would take the one with the highest MP. He is not alone, for sure.

But's it's very interesting to hear what the inventor of CMOS sensors has to say on exactly this issue:

https://youtu.be/JkBh71zZKrM
That is very interesting. Thank you for the link.

Now some think when you downsize a 42mp to 24mp the diffraction effects, which are greater at f/11, will magically disappear and the two images will be the same.

I don't really know, but I would like to find out, because I do shoot a lot of landscapes and I do use f/11 often :)

Basically, your question is "which camera will give the sharpest results at f/11 when downsized to 24mp?". The simple answer is the 42mp camera, but the gain will be minimal.

The full answer is complex, because diffraction is not a hard limit and can be compensated visually a bit (with emphasis on "visually" and "a bit") and also because smaller pixels get the benefit of better color sampling (Bayer array structures are still larger than the diffraction spot).

The video is more relevant to smart phones and their tiny pixels. The engineer building those and other cameras with similar sensors like P&S or video cameras already know they cannot use small apertures. This is the reason why these cameras use a ND filter internally instead of a diaphragm and usually run their lenses full open all the time. Then, otoh, using a lens full open means one has the full effects of optical aberrations, the lens designer can only do so much.

In practice, for real life photography, that means the following:

-if one photographs flat subjects (distant landscape, astronomy, test charts): the optimal aperture for sharpness will be around f/8-f/11 for 24mp and f/5.6-f/8 for 42-50 mp (on a 24x36 sensor size). These are not hard numbers and indeed one can use f/16 with visually sharp images with the help of advanced sharpening techniques.
-if one wants to use f/11 because of depth of field, the 42mp camera will be a tiny bit sharper on extremely large prints (at least 18"x24" ~ A2 size).
 

Annna T

Active member
In the context of this thread, This comparison may be of interest :


Sony A7R II vs. A7 II - Print Test - Admiring Light

Admiring light compared the 24MP A7II to the 36MP A7rII at two different print sizes and at F8 or F11.

He comes to the conclusion that there is a difference but it is subtle with the A7rII showing a little more details. He has downloadable raws and 100% crop of the prints.
 
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daf

Member
In the context of this thread, This comparison may be of interest :


Sony A7R II vs. A7 II - Print Test - Admiring Light

Admiring light compared the 24MP A7II to the 36MP A7rII at two different print sizes and at F8 or F11.

He comes to the conclusion that there is a difference but it is subtle with the A7rII showing a little more details. He has downloadable raws and 100% crop of the orints.
That the perfect link !
To resume:
-if you print A1 or smaller 24mpx is enough
-If you print larger, with 42mpx you'll start to see a difference, if you print much larger you'll probably see a very big difference.
-if you want/need to crop a lot you'll also see a big difference.
 

ErikKaffehr

Well-known member
Hi,

That is sort of what I have seen when i compared my Sony Alpha 99 (24 MP) with my P45+ back (39 MP). No visible difference at A2-size. At A1-size I think there was a visible advantage to the P45+, though.

If I looked at the images with a loupe, the P45+ had an advantage. So it was not printing that was the limiting factor but my vision. Young people with perfect vision may be able to see differences that I may not.

Best regards
Erik



That the perfect link !
To resume:
-if you print A1 or smaller 24mpx is enough
-If you print larger, with 42mpx you'll start to see a difference, if you print much larger you'll probably see a very big difference.
-if you want/need to crop a lot you'll also see a big difference.
 
In the context of this thread, This comparison may be of interest :


Sony A7R II vs. A7 II - Print Test - Admiring Light

Admiring light compared the 24MP A7II to the 36MP A7rII at two different print sizes and at F8 or F11.

He comes to the conclusion that there is a difference but it is subtle with the A7rII showing a little more details. He has downloadable raws and 100% crop of the prints.
Can you give me the link to the raw files? I can't find them anywhere in the article. Thank you.
 

ErikKaffehr

Well-known member
Hi,

On the other hand the images from DPReviews image comparison tool tell a story of cleanness of resolution. Admittedly this is a difficult case, with fine detail having high contrast and photographed under ideal conditions with high resolution lenses.

Screen Shot 2015-11-06 at 23.52.25.jpg

Interestingly, out of the camera JPEGs don't show colour artefacts.
Screen Shot 2015-11-06 at 23.58.57.jpg

Best regards
Erik
 

algrove

Well-known member
So where are we on this thread?

If someone is in the market for a new FF 35mm camera, should they even consider a 24MP body versus something higher like 36 or 42?

Sony touts the 42 and Leica has just decided to stick with 24. I frankly believe Leica is stuck in that range due to their flagship S at 37.5MP.

Do I print? Yes. How large? Well, I am contemplating getting a 24" printer and I crop to whatever it takes to please me and that is sometimes a 50% crop. Do I stitch? Yes. Sometimes I merge 8-12 images together for landscape scenes.

TIA for any solid comment.
 

Lucille

New member
And to think some of us have to struggle with the wimpy 12mp from the Sony A7S.


 
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jerome_m

Member
So where are we on this thread?

If someone is in the market for a new FF 35mm camera, should they even consider a 24MP body versus something higher like 36 or 42?
For most uses, 24 MP is sufficient. From experience with the A900 and then the RX-1, I would even say it is a sweet spot, a good compromise between resolution, iso, lens abilities, camera shake, AF abilities and depth of field.


Do I print? Yes. How large? Well, I am contemplating getting a 24" printer and I crop to whatever it takes to please me and that is sometimes a 50% crop.
In that case, maybe a larger resolution like 36 or 42 would be advantageous for you.
 

ErikKaffehr

Well-known member
Hi,

I have made exhibition quality prints from 12MP APS-C in A2-size. Many of my best images were shot on 12 MP APS-C, and I have made many very good prints from those.

At the time I went from 12MP APS-C to 24MP on full frame I was stunned to see how little difference there was between A2-prints from those formats.

So, I feel that say 16-24 MP can be perfectly good for A2 size prints.

Two and a half year ago I bought into medium format shooting 39MP, and I could not at that time see differences from 24MP to 39MP in A2 size prints. I did not make any print comparisons between my A7rII and my other cameras yet, but I have seen some issues with raw conversion on the A7rII using Lightroom 6.2. RawTherapee with the AMaZE algorithm did a much better job on this:
Screen Shot 2015-11-07 at 08.16.11.jpg
Here is a link to a full size image.
I had a discussion on this on LuLa as I feel Adobe needs to work on their raw conversion. On that thread Mark Segal pointed out that those artefacts are not visible in a 45" print. I did a print a crop of corresponding size and made some very interesting observation.

Some facts: I am 60 years old (a couple of days not counting) and I am nearsighted. Have around 20/20 vision with corrective glasses.

So, what I have found was that I could see those jagged lines viewing close (say 12" / 30 cm) without glasses. Moving away from the print I could no longer observe those jaggies. With progressive glasses I was not able to observe those jaggies at any distance. A young person with good accommodation of vision would probably be able to see them easily.

That said, I still would prefer an image without those artefacts, but fact is that our vision is limited and can hide a lot weaknesses in rendition. Still I feel that good and correct rendition is a good thing, but once we are past the 12 MP on A2 (or so) we are entering the diminishing returns region. We still get benefits from increasing resolution but those benefits may be less obvious.

Best regards
Erik

And to think some of us have to struggle with the wimpy 12mp from the Sony A7S.
 
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