p.2 #2 · Diffraction the great equalizer? (Guess what the lenses are)
That's part of the reason I love the Pentax, I think it pairs well with the other Zeiss lenses I have.
-Tim
DaveFP wrote:
I would have picked #2 as having the most "Zeissyness".
Apr 27, 2019 at 09:01 AM
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p.2 #3 · Diffraction the great equalizer? (Guess what the lenses are)
The images are indeed very close, but to me the angle of view gave it away. You can see that the Loxia images are just a bit wider. Have you every considered focus stacking as an alternative to f/16. I think two shots ought to do it here? Not sure it would work, but I wonder how it would compare.
p.2 #4 · Diffraction the great equalizer? (Guess what the lenses are)
NIce and thanks. I picked #2 as the Zeiss at first as well, mostly because the deeper, more contrasty shadows. I think there's a slight exposure difference though. The f/11 shots that difference looks to be less, and the shadows also look closer.
I'd have bet another box of donuts that the old lens was the 28/3.5 based on who posted the test but didn't guess the Loxia. Just makes me want a Lox 25 more...
p.2 #5 · Diffraction the great equalizer? (Guess what the lenses are)
tsdevine wrote:
I didn't use the diffraction setting as C1 in it's wisdom doesn't allow you to set the aperture with manual lenses (for this feature), so I turned it off in order for parity in processing for comparison purposes.
You can compensate for diffraction in C1 by going to the "movement" panel of the lens correction section and manually entering the aperture. I haven't figured out how to make that stick (as with a style setting) so it may be that you have to enter it for each shot--but it seems to work.
p.2 #6 · Diffraction the great equalizer? (Guess what the lenses are)
For some reason it is grayed out for the Pentax shots. I can't edit it and it's stuck at 0 as the aperture.
-Tim
zugzwang2 wrote:
You can compensate for diffraction in C1 by going to the "movement" panel of the lens correction section and manually entering the aperture. I haven't figured out how to make that stick (as with a style setting) so it may be that you have to enter it for each shot--but it seems to work.
p.2 #7 · Diffraction the great equalizer? (Guess what the lenses are)
tsdevine wrote:
That's part of the reason I love the Pentax, I think it pairs well with the other Zeiss lenses I have.
-Tim
Tim,
Did you do an aperture series? Say from f/4 until f/16?
It would be interesting to see at what point, the Pentax starts to look better towards the corners.
I remember testing the 28/3.5K (that one I sold to you was 100% centered) and it was great but not remarkable at f/5,6 and f/8 with a distinctive mid-field dip at wider apertures.
I still find this puzzling. A lens that does better at f/4 towards the corners when compared to a weaker lens, should still do better at f/11 and f/16.
p.2 #8 · Diffraction the great equalizer? (Guess what the lenses are)
tsdevine wrote:
I'm not sure any ruining of the shot is solely the aperture here. I'm reacquainting myself with C1 (and playing around with some others) as I'm hedging my bets on my normal go to RAW processor. I've been using Photo Ninja for quite a few years, but there hasn't been many updates in a long time. They are supposedly rewriting it.....but that's been the guidance for years as well. So I'm not extremely comfortable with the controls yet.
I also didn't tailor sharpening for the f/11 shots as I wanted to use the same settings as f/16, so that people could compare apples to apples.
I didn't use the diffraction setting as C1 in it's wisdom doesn't allow you to set the aperture with manual lenses (for this feature), so I turned it off in order for parity in processing for comparison purposes.
Well maybe my comment was a bit harsh, The shots are certainly not ruined if viewed at normal enlargement. Certainly a bit soft compared with the f11 sample. I think I was expressing my frustration in having to deal with the same issues under some conditions, although your samples look worse than I've seen before. Excellent job illustrating that problem.
p.2 #9 · Diffraction the great equalizer? (Guess what the lenses are)
tsdevine wrote:
For some reason it is grayed out for the Pentax shots. I can't edit it and it's stuck at 0 as the aperture.
-Tim
That's interesting. The diffraction correction works for me (in 12.0.3 Pro for Sony) with two adapted (ZM) lenses, regardless of whether I assign a generic or sorta-similar lens profile in C1 to the unrecognized adapted lens.
p.2 #10 · Diffraction the great equalizer? (Guess what the lenses are)
Fred,
I have f/8 through f/16. As you go from f/11 to f/9.5 to f/8, you start losing extreme corner sharpness and enough DoF that I'd rather trade a little sharpness for more DoF foreground sharpness. The Loxia becomes stronger and it becomes an unfair fight. Modern WA lenses seem to have improved so much at faster apertures.
I don't believe that a lens that is better at f/5.6 than another lens will be guaranteed to better than that lens at f/16. I believe there are design choices that impact performance at various apertures, outside the normal dulling of sharpness due to diffraction. Look at these Les Numeriques charts for the Batis 40mm f/2 and Samyang 35mm 1.4. Notice the nose dive at f/16 for the Batis. If it were purely diffraction, why no nose dive for the Samyang? Maybe the Samyang actually resolves more than the Batis, but not at the tested distance (until stopped down.) Maybe some lenses aren't optimal at distances as you stop down past a certain point. Could it be modern designs that take advantage of the shorter flange distance struggle with ray angle when stopped down? Could it be some other design choice? Maybe I just did something wrong in the test....
p.2 #11 · Diffraction the great equalizer? (Guess what the lenses are)
I have the Pro, non-Sony version. Maybe that's it...
-Tim
zugzwang2 wrote:
That's interesting. The diffraction correction works for me (in 12.0.3 Pro for Sony) with two adapted (ZM) lenses, regardless of whether I assign a generic or sorta-similar lens profile in C1 to the unrecognized adapted lens.
p.2 #12 · Diffraction the great equalizer? (Guess what the lenses are)
No doubt the f/16 version isn't spectacular, but it's passable at least for my tastes. Sharpness (too a lesser extent detail) preferences vary a little bit between people. The times where I may feel the need to stop down to f/16 is portrait orientation shots where I want even sharpness (even if compromised somewhat) from foreground to distance. Talking landscape shooting here.
And it sound like you are sympathetic to the challenges there. It's a shame diffraction exists.... There always seems to be something to muck things up.
-Tim
stevesanacore wrote:
Well maybe my comment was a bit harsh, The shots are certainly not ruined if viewed at normal enlargement. Certainly a bit soft compared with the f11 sample. I think I was expressing my frustration in having to deal with the same issues under some conditions, although your samples look worse than I've seen before. Excellent job illustrating that problem.
p.2 #13 · Diffraction the great equalizer? (Guess what the lenses are)
Per Fred's request, here are f/8 shots. You'll see why I shoot the Pentax at f/11 normally. And you'll also see the Loxia shine.
I don't mind shooting the Pentax at f/11 for landscape shooting, but I know others may be uncomfortable having to stop down that far in normal use.
Now I left the sharpening as it was in the other shots, and the Loxia is oversharpened for my tastes as a result. But it allows you to see how the sharpness slides from f/8 to f/11 to f/16.
p.2 #15 · Diffraction the great equalizer? (Guess what the lenses are)
That's funny - I just today received my copy of the Pentax K (via Ebay, 100 Euros).
Took some test shots - awesome! Not only very good sharpness, but especially the colors which really pop! With no other lens I have or had I have to tweak so little in Lightroom to get a punchy (but in no way "overblown") photo!
That the Pentax is superior in this regard to the Loxia can be seen clearly in the above comparison shots.
p.2 #16 · Diffraction the great equalizer? (Guess what the lenses are)
Tim, When Sony introduced the A7R, they elaborated on how the system lenses would miminise the diffraction effect digitally.
With the Loxia having a chip (albeit lacking the distance information) would help the camera to do that. Any non system lens would lag behind when it comes to this.
tsdevine wrote:
Per Fred's request, here are f/8 shots. You'll see why I shoot the Pentax at f/11 normally. And you'll also see the Loxia shine.
I don't mind shooting the Pentax at f/11 for landscape shooting, but I know others may be uncomfortable having to stop down that far in normal use.
Now I left the sharpening as it was in the other shots, and the Loxia is oversharpened for my tastes as a result. But it allows you to see how the sharpness slides from f/8 to f/11 to f/16.
p.2 #19 · Diffraction the great equalizer? (Guess what the lenses are)
realVivek wrote:
AFAIK, it is baked into the RAW files.
My recollection is that the decovolution used for diffraction compensation with Sony is only in the JPEG.
And they aren’t even part of the mandatory profiles for C1 or LR. So you need to deconvolve yourself in RAW if you want.
Do you have a reference or link? I’d be interested if this were not so...
but didn't guess the Loxia. Just makes me want a Lox 25 more...