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09-30-2018, 01:41 AM   #46
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Lenstip/Optyczne.pl went to Photokina and made a few samples with both the Pentax and Tokina Opera 50mm.

Some of them below (all at 1.4):
http://pliki.optyczne.pl/Photokina_2018/pentax_50_1.4/IMGP0348.JPG
http://pliki.optyczne.pl/Photokina_2018/pentax_50_1.4/IMGP0356.JPG
http://pliki.optyczne.pl/tokina50opera/498A9733_50mm_f140.JPG
http://pliki.optyczne.pl/tokina50opera/498A9671_50mm_f140.JPG

Not too bad, but I don't like that Olympus logo (it doesn't seem much of a stress test).

09-30-2018, 04:33 AM   #47
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QuoteOriginally posted by BarneyL Quote
Lenstip/Optyczne.pl went to Photokina and made a few samples with both the Pentax and Tokina Opera 50mm.
The fact that the Opera lens also produces purple fringing wide open is not exactly a shock
09-30-2018, 05:31 AM   #48
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f it doesn't purple fine, its probably not a lens. DO pin holes purple fringe? Maybe that's the "no friging" solution.
09-30-2018, 08:45 AM   #49
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QuoteOriginally posted by normhead Quote
f it doesn't purple fine, its probably not a lens. DO pin holes purple fringe? Maybe that's the "no friging" solution.
Going so far is not needed
All "true" Apo lenses don't fringe in visible light. IR or UV lenses don't fringe even outside visible light.
Of course you can't have the cake and eat it. AFAIK there are no super fast Apochromatic optics.
Actually there not so many lenses that actually focus three colours/wavelengths in the exact same point, and those designed to do that are not cheap.
I think it doesn't make much sense to nitpick about the D FA 50mm.
Probably some lenses sold as Apo (for example some Sigma's) weren't any better. Maybe even worse.
In the upcoming days I will test the Apo Telezenitar 135mm, which is the only non-specialistic objective called "Apo" by the russian. I've been told that even this optic is not fully apochromatic...
Few prosumer lenses truly deliver what they promise.

Considering the fast aperture, the D FA does very well at the center, and good enough at the borders (going by the chart tracing LaCA width).
I don't think LoCA has ever been measured, cause it does not happen on the plane of focus (thus depending on variable/s).
I think it makes sense to report about CA problems, so that perspective buyers know what to expect (and what are unrealistic expectations).
Though it seems there is nothing worth complaining, comparing the D FA to the possible alternatives.

09-30-2018, 09:05 AM   #50
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QuoteOriginally posted by cyberjunkie Quote
All "true" Apo lenses don't fringe in visible light. IR or UV lenses don't fringe even outside visible light.
So if there aren't any "true Apo" lenses, then, back to the pinhole.
09-30-2018, 09:57 AM   #51
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Pinhole also purple fringes, diffraction depends on the wavelength...
Fringing can be corrected more then it made in the DFA*50, but fringing is an easy to correct error, so I think this is why the lens designers decided to put in another correction element.
09-30-2018, 10:05 AM   #52
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QuoteOriginally posted by normhead Quote
So if there aren't any "true Apo" lenses, then, back to the pinhole.
Hahaha, believe it or not, when I switched to full digital from large format for lack of darkroom, the first thing i wanted to buy was a lens cap with a laser cut pinhole!
It never materialised...
I would like to believe that there are no Apo lenses available for PK, but there are a few that can be leitax'ed (Leica Apo's are not impostors; plus the likes of the Apo Planar, Apo Sonnar, etc.). A pity my wallet is already crying loud
AFAIK the 50mm and 100mm macro made by Pentax are "almost" Apo. Pentax correctly does not market them as such, though the fringing is minimal.
For the patient fellows who stack ultra macro shots with special (or microscope) objectives there is an ample choice of true apochromats.
All in all, I'd say that there are ways to shoot with a true apo, making use of some ingenuity and investing some good money.
Though in theory you are perfectly right: pinholes are not affected by most optical aberrations, and on top of that the DOF is incredible... if only we could magically get rid of diffraction!

JUST A THOUGHT:
I am quite surprised that most of those who actually care about border to border sharpness, flat field, and zero CA have never tried to experiment with repro lenses. Most of them were called Apo (Apo Geronar, Apo Tessar, Apo Skopar, Apo Ronar), and those that were not sold as Apo had more or less the performance of the others (like the G-Claron, Repro-Claron and Repromaster).
Unfortunately the speed was very low, and most of them had long focals. The only ones I know under 150mm are the Repromaster 80mm and 135mm, and the Repro-Claron 135mm and 55mm.
The low speed was a big problem with an optical viewfinder.
I have seen a few incredible contraptions used as poor man's long tele. Not much more.
No surprise it was not a very popular solution for other applications.
Now with Live View it should me more doable. A simple adapter ring and a set of ring/bellows is all is needed.
Instead of a very long focal, one of the shortest ones could be used for table top and macro photography.
Sharpness on a high density sensor should not be top notch anymore, but all the other pros should still hold true.
I would be curious to see the result, if anybody ever decides to give it a try.
Maybe it's not as silly an idea...


Last edited by cyberjunkie; 09-30-2018 at 10:22 AM.
09-30-2018, 10:42 AM   #53
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The question as always would be how much correction can you do and what are the trade offs. I have lenses that I know are prone to purple fringing, but they don't have purple fringing on most images. So IMHO it's not a huge issue.

I suspect for most, we'd rather keep our dollars and suffer a little purple fringing and CA every now and then. I know I would.
09-30-2018, 11:11 AM   #54
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Oh well. I guess I’ll just sacrifice all the f/1.4 shots of green chain link fences and backlit domes I had planned to capture with my new normal lens and go about my business shooting everyday life.
09-30-2018, 04:48 PM   #55
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This was a pretty interesting review... I made the mistake of buying the new fat fifty with all crop bodies... Said wow this thing is stupid good and decided a couple months later to get a K1 II for the fat fifty.

Honestly this lens renders so incredibly awesome... The images appear almost 3D, I have been shooting between 1.4 and 2.8 with an occasional stop down to 4. This thing can do landscapes wide open or stopped down a tad to like 2 or 2.8 it is incredible.

Planning on doing some couples photos for my sister and her boyfriend soon. Actually looking forward to the results will be the K1 II with this lens only.
10-01-2018, 06:53 AM - 1 Like   #56
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QuoteOriginally posted by monochrome Quote
Oh well. I guess I’ll just sacrifice all the f/1.4 shots of green chain link fences and backlit domes I had planned to capture with my new normal lens and go about my business shooting everyday life.
The green chain link fence in the DPReview test was hilarious. Exactly what colour were they expecting a green chain link fence to be?
10-01-2018, 08:07 AM   #57
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Uhh... gray 18%? I thought that was obvious!
10-01-2018, 08:32 AM   #58
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QuoteOriginally posted by Wheatfield Quote
The green chain link fence in the DPReview test was hilarious. Exactly what colour were they expecting a green chain link fence to be?
Obviously they expected it to be red. Because obviously when you photograph a green fence, the opposite color is supposed to result.
10-01-2018, 09:31 AM   #59
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You're talking about the same dptabloid whose interns find shooting moving targets symbolizing "sports" with a camera firmly attached to a tripod is relevant practise for someone.

No surprise about the fence fail.
10-02-2018, 10:40 AM   #60
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I did my lens calibration for the *50 before re-calibrating FA77. The 50 looks fine even on high contrast targets, the 77 shows purple fringing. In real live the 77 has very nice bokeh and the 50 produces very clean imagery. I don't typically photograph fences.
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