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12-04-2022, 02:01 PM   #31
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QuoteOriginally posted by pschlute Quote
I did a little test today. It certainly does vignette substantially on full frame, but less so on aps-c. It is still there though, which was not what I was expecting, so thanks for pointing that out.

I did a further experiment at close focussing sharpness. The camera was 3 feet away from the wine bottle, on a tripod, EFCS engaged in LV to avoid any shutter shock, 2 sec timer. The results show what I have always known, the A-50mm 1.2 is very soft wide open in the plane of focus. it is acceptably sharp at f2.0 and very sharp at f8. These are 100% crops.
Call me anything but what you call soft at f1.2 I call out of focus ! It’s way too blurry and my OCD can’t stand it. Is it possible you misfocused on f1.2?

12-04-2022, 02:04 PM - 1 Like   #32
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From my experience with my copy of the A1.2/50 I would say that at f1.2 the wine bottle is not exactly in focus. :-)

Generally I prefer the DA*1.4/55 in most situations as it is much easier and faster to use on a digital body unless you really have sufficient time to carefully focus manually.

Also I would like to mention that on my K3/K3II with a cheap chinese 1.51x mangifying eyepiece AND with the correct diopter setting, manually focusing on the matte screen works much better for me than the green hexagon.

Greetings, Arnold
12-04-2022, 02:07 PM   #33
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QuoteOriginally posted by Athanassios Quote
PS: I had actually read the article before ( not with much due diligence I admit cause it involves some not so exciting parts)
LOL! Sorry about that... my engineering/scientific background is rooted pretty deeply.

- Craig
12-04-2022, 02:14 PM   #34
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QuoteOriginally posted by c.a.m Quote
LOL! Sorry about that... my engineering/scientific background is rooted pretty deeply.

- Craig
Sorry!!!! I just got REALLY lost into the technical analysis while I was looking for hands down tips. My bad

12-04-2022, 03:41 PM - 1 Like   #35
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QuoteOriginally posted by Athanassios Quote
Sorry!!!! I just got REALLY lost into the technical analysis while I was looking for hands down tips. My bad
No worries!

I laugh at myself frequently... Sometimes I think that my professional background has hampered my photographic creativity. But I'm working on it.

- Craig
12-04-2022, 03:52 PM - 1 Like   #36
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QuoteOriginally posted by Athanassios Quote
Call me anything but what you call soft at f1.2 I call out of focus !
Here are the full images. You tell me where I missed focus. Dropbox - A 50mm 1.2
12-04-2022, 04:55 PM   #37
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Here are the full images. You tell me where I missed focus. Dropbox - A 50mm 1.2
My dear Pentaxian friend, I did not mean to insult you. I also did some tests on f/1.2 just now with some minor twicks on the body and the results are phenomenal ie razor sharp at f 1.2 ! I will post the details right away on a separate comment here. Have a look

12-04-2022, 05:08 PM   #38
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ok, listen up!

I did some KP menu adjustments and the results are great!

a) on the main menu I cranked up the "Clarity" to maximum +4
b) on the C4/23 FINE ADJUSTMENT I did calibrate the lens as it is back-focusing at -10 and yes, I think it works not just for AF lenses but manual focus glasses too; like the Grenade. The manual doesn't say that it's AF lenses only.

c) Last but certainly not least I set the C4/22 CATCH-IN FOCUS to ON where it "Enables Catch-in Focus shooting when a manual focus lens is attached. The shutter is released automatically when the subject comes into focus." That was a life saving trick since you hold down the shutter release button and it shoots as soon as the subject is in focus. As I said before, at F/1.2 the hexagon/focus indicator shows up in a very tiny space/with of the focus ring and it was time consuming to "lock" the focus as I was micro adjusting the ring to find that perfect spot that I had just passed.

So your shutter button is pushed down and it's on a "stand by" mode and shots the moment the subject is in focus. While doing that I was rotating the focus ring VERY SLOWLY right before the spot I knew that the "focus" was coming. My success rate for razor sharp went to almost 9/10. I only still haven't figured out if its better to turn the ring from the left or from the right towards the focus point. Meaning whether it's better to start from infinity or minimum distance.

The images I guess speak of themselves. All in F 1.2

PS: In photoshop I still use the lens profile of the old 50/1.4 M42 etc as I stated above.

---------- Post added 12-04-22 at 05:13 PM ----------

QuoteOriginally posted by pschlute Quote
Here are the full images. You tell me where I missed focus. Dropbox - A 50mm 1.2
My dear pschlute

If you compare my eg BU college cap or the numbers on the phone you can see that at f1.2 there is a chance to get razor sharp images. They are actually so sharp that I think the +4 clarity is not the reason. I think the reason is the "catch-in focus"

I hope I didn't offend you with my previous post. I am an OCD freak in photography on two things: low light shooting and sharpness.

Take Care and thanks for posting everything including the original photos of the wine which I wish you enjoy it empty.

Last edited by Athanassios; 12-19-2022 at 10:31 AM.
12-04-2022, 05:22 PM - 4 Likes   #39
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QuoteOriginally posted by AfterPentax Mark II Quote
That is what I thought too! If you have back (or front) focus with a manual lens it is you that should be calibrated, not the lens/camera combination...
The autofocus system is used with manual lenses ... for the focus confirmation feature.

That of course needs to be calibrated like any lens.
12-04-2022, 09:21 PM - 1 Like   #40
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QuoteOriginally posted by pschlute Quote
Here are the full images. You tell me where I missed focus
The ƒ1.2 is back focused placing the focus plane behind the lettering on the bottle
12-04-2022, 09:59 PM - 2 Likes   #41
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QuoteOriginally posted by Ian Stuart Forsyth Quote
The ƒ1.2 is back focused placing the focus plane behind the lettering on the bottle
I will give it another try tomorrow. Maybe I have a very soft copy of the lens, or maybe I should have left the wine in the bottle before attempting the test

Last edited by pschlute; 12-04-2022 at 11:56 PM.
12-04-2022, 10:12 PM - 2 Likes   #42
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QuoteOriginally posted by pschlute Quote
Maybe I have a very soft cop of the lens,
If you compare the sharpest area in the photo the lens is really not that bad



The crop is taken from the focus plane
12-04-2022, 11:30 PM - 2 Likes   #43
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I shot the A50/1.2 against the DA*55 for a month a few years ago.

Have a look at my Flickr album and see if that helps. In many instances it was hard to tell the two apart, and the others who were following the month in the Single In Challenge were often divided as to which shot they preferred. More often than not it boiled down to differences in lighting or point of focus.

If I were you, I would stick with the DA*55
12-05-2022, 12:09 AM - 3 Likes   #44
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I'm glad you discovered "catch in focus"- I assumed you were using it so never mentioned it.

**Thank you to Pschlute and Clackers for pointing out calibration is actually possible.
This thread has also had me messing around with my Revuenon 55mm F1.2 since yesterday and realising that with some tweaking of the DNG files in DXO, F1.2 shots can be very sharp, much better than I at first thought possible.

Last edited by Unregistered User; 12-05-2022 at 04:56 AM.
12-05-2022, 05:02 AM - 1 Like   #45
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QuoteOriginally posted by Athanassios Quote
Take Care and thanks for posting everything including the original photos of the wine which I wish you enjoy it empty
Thank you. I did enjoy the wine, which may explain the soft quality of the wide open image
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