[Athanassios]

Hi Y'all

Yesterday I received a mint with super clean glass copy of Pentax-A 50mm/F1.2 for 570 €/$.
The moment I put it in my hands reminded the grenades I used in the army so hence its baptism "GRENADE". Not to mention that you're like holding a grenade ready to explode heavenly or crappy photos.



Before I even received the glass I pre-ordered a "cinematic" metal hood for a vintage/sexy touch for 45€/$; the most expensive but better quality/looking.

I also ordered a "vintage" case for 25€/$ to keep the Grenade safe and happy

Total cost 640 €/$ for the exception to all my 7 Limited+Biscuit (the XS...) primes (my zoom collection is an irrelevant story).




NOW.... my problems for which I ask your help. Please note that both my cameras are KPs and I got it in order to use it almost exclusively wide open at f/1.2 for street-shooting, night shooting and why not .... ASTRO. And of course always in DNG never jpg ( any difference in PEF?; don't know)


I don't plan on using if for bokeh-close ups in flowers or portraits as I already have the HDs 35/2.8 & 100/2.8 for macros as well as the SMC 70/2.4 Limited for portraits.

1. It back-focuses a couple inches ie the focus is some 2 inches toward the camera. In the Menu C4 it ONLY allows me to adjust the callibration for ALL lenses. The "just this lens" in disabled !!!

My only option is to callibrate every time I use this glass and then recallibrate after I finish shooting with the chance I forget. Have I messed any other settting that makes the "only one lens" callibration off?

2. Even at -10 callibration and with the green pentagon "Focus OK sign" on the viefinder the copy seems to be again backfocusing a bit Some times I even feel that its focus on the image is leaning towards the right So, is there any other way to reduce the back-focusing with some ViewFinder menu adjustments?

3. Focus is only in SPOT. Any chance to change that?

NOTE: In LIVE VIEW MODE the focus works fine; even without callibration!!! What does that mean?

4. I shoot in P mode since the U4 mode that is for Manual lenses messes with the Aperture and it's not that customizable. I still may be using it as "auto" mode in night-outs where I won't be bothering too much with "adjustments". Yet, I'll be always using the green-dot button for metering before adjustments or any shooting mode.

5. In Photoshop there is no "lens profile" for this glass so I am using the "closest one" I can find ie the "Asahi PENTAX Super-Takumar 50mm/f1.4 M42". Has any one else used a lens profile before other than that? The differences are huge!

6. In the RAW profile I realized that I need " Adobe Standard" Profile for the colors, an increase to 62 the Texture in the Basic menu, an 120 in sharpness with 3.0 radius and a 25 Noise Reduction (all these three twicks in the Detail mode). Plus an AUTO in edit adjustmens which I will be later changing if needed per DNG.

ALL these because they truly bring the image/glass close to modern DA resolution/sharpness and I am familiar with "DNGs basic" post processing for 20 years. I don't photoshop the photo beyond it's natural essence.

Does anyone else have/using a different setting? This I've saved this as a present for this glass.

Below first sample photos using the KP with the "Grenade" and all the callibrations and adjusments I mentnioned.

I am 16 years in Pentax mostly Limited Primes and this is my first "manual F" glass.

ALL HELP, COMMENTS, ADVISE will be most greatly appreciated!!!

Thanks,
Athanassios

PS: I am so puzzled and I really wonder whether I should trade it with a brand new SMC Pentax-DA* 55mm F1.4 SDM or a mint used of HD Pentax-D FA* 50mm F1.4 SDM AW. It's not that "I need practise". I love f/1.2 but I wonder whether I am just a DA guy. All these focus callibrations and photoshop adjustments seem unnatural to me since I can today simply shoot, put the proper "lens profile" and have top images.


All photos wide open at f/1.2

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Last edited by Athanassios; 12-03-2022 at 02:23 PM. Reason: syntax

[boriscleto]

If you don't have a specific need for f1.2 trade it for the new D FA...

Youtu.be

Youtu.be

[pschlute]

My only option is to callibrate every time I use this glass and then recallibrate after I finish shooting with the chance I forget. Have I messed any other settting that makes the "only one lens" callibration off?

What you can do is to calibrate with the green hexagon in the APPLY ALL setting. Then afterwards put a calibrated autofocus lens on the camera and in the AF/FA menu select APPLY ONE, and exit the menu. now in future any of your calibrated AF lenses will be individually adjusted , but any non-calibrated lens (including the A 50mm 1.2) will default to the APPLY ALL setting.

[pschlute]

2. Even at -10 callibration and with the green pentagon "Focus OK sign" on the viefinder the copy seems to be again backfocusing a bit

Do your autofocus lenses need adjustment this extreme ?

To be honest, the green hexagon (or beep) will have too much leeway to be very useful when taking close range pictures with a f1.2 lens. You can test this yourself by focussing on the same object, but first from the close focus distance, and secondly from the infinity side. Note where the lens stops each time, they wont be in the same position !

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Last edited by pschlute; 12-03-2022 at 06:54 AM.

[pschlute]

Focus is only in SPOT. Any chance to change that?

No. You are limited to spot focus only

NOTE: In LIVE VIEW MODE the focus works fine; even without callibration!!! What does that mean?

They are two different systems.

4. I shoot in P mode since the U4 mode that is for Manual lenses messes with the Aperture and it's not that customizable. I still may be using it as "auto" mode in night-outs where I won't be bothering too much with "adjustments". Yet, I'll be always using the green-dot button for metering before adjustments or any shooting mode.

Set the aperture ring to the "A" setting and then you can use any of the cameras metering modes including AV and Tv

[pschlute]

5. In Photoshop there is no "lens profile" for this glass so I am using the "closest one" I can find ie the "Asahi PENTAX Super-Takumar 50mm/f1.4 M42". Has any one else used a lens profile before other than that? The differences are huge!

I suggest you dont use any profile for it. 50mm lenses usually have the least distortion of all.

All these focus callibrations and photoshop adjustments seem unnatural to me since I can today simply shoot, put the proper "lens profile" and have top images.

If your camera requires -10 or more with a manual lens then you will surely have to do a focus adjustment with any new lens you buy. It sounds like the AF module is right at the extreme level of manufacturing tolerance.

If you are not comfortable processing the raw file, then just shoot jpeg straight from the camera.

[Athanassios]

Do your autofocus lenses need adjustment this extreme ?

unfortunately yes the "Grenade" needs an extreme one. All the others are just fine. And your above suggestion I'll try even if I am afraid that it may not apply for all AF lenses but just that one. I guess it's "play safe" to decallibrate ie turn to zero the setting after every use of the Grenade.

I added some more photos. What I realized is that the lens "suffers" from highlights that Photoshop reduces to -80! and the photo then turns to a really great one. -80! highlights with ISO 100 inside a shadow room. This lens devours light like noone else for sure.

---------- Post added 12-03-22 at 06:57 AM ----------

If you don't have a specific need for f1.2 trade it for the new D FA...

https://youtu.be/KOO5S4vxi0o

A Kilo/ 2 pounds heavy and twice the cost and the height. I don't think the D FA 50/1.4 is for street walking in the night.

---------- Post added 12-03-22 at 07:00 AM ----------

Set the aperture ring to the "A" setting and then you can use any of the cameras metering modes including AV and Tv

Already did straight from the start. What I ment is that the U4 is not like P where you can dial whatever you want or the M ( and in both cases the camera adjusts the other settings when you change one among the rest three).

What I also see is that the lens works much better at much higher speeds as if the Shake Reduction is not that helpful for some reason. May be because the glass is to large ie lowest aperture possible in Pentax.

---------- Post added 12-03-22 at 07:03 AM ----------

I suggest you dont use any profile for it. 50mm lenses usually have the least distortion of all.



If your camera requires -10 or more with a manual lens then you will surely have to do a focus adjustment with any new lens you buy. It sounds like the AF module is right at the extreme level of manufacturing tolerance.

If you are not comfortable processing the raw file, then just shoot jpeg straight from the camera.

I have to because the RAW has alot of distortions and vingetting at f1.2. All my other lenses are razor sharp focus.

Below a photo with the HD 35/2.8 Macro Limited at f 22. Everything in focus is perfect. (same at f/2.4-2/8 in all my other DA AF glasses)

And I always shoot DNG for their advantages.

[steephill]

Adobe had a now defunct system for collecting user generated lens profiles and making them available for download. Someone (Beholder3?) had created a profile for the A50 f1.2 using a K5 which I have used in Lightroom.

Originally posted by pschlute Quote
Do your autofocus lenses need adjustment this extreme ?

unfortunately yes the "Grenade" needs an extreme one. All the others are just fine. And your above suggestion I'll try even if I am afraid that it may not apply for all AF lenses but just that one. I guess it's "play safe" to decallibrate ie turn to zero the setting after every use of the Grenade.

But this lens is manual focus not auto focus.

[boriscleto]

A Kilo/ 2 pounds heavy and twice the cost and the height. I don't think the D FA 50/1.4 is for street walking in the night.

Then use live view. I bought a used Fujifilm X-T20 for manual focus lenses, because contrast detect and focus peeking is just better for manual focus. Plus I can use just about any lens mount with a simple adapter.

I have a KP and a Revuenon 55mm F1.2 and can focus it through the OVF wide open but I am a bit confused by the performance of AF lenses at f2.8 - f22 being some kind of reference - have you tried this 50mm at f2.8 or f8 etc?

[pschlute]

I have to because the RAW has alot of distortions and vingetting at f1.2

You are using a f1.2 full-frame lens on a KP aps-c sensor. How can it vignette ?

[Just1MoreDave]

PS: I am so puzzled and I really wonder whether I should trade it with a brand new SMC Pentax-DA* 55mm F1.4 SDM or a mint used of HD Pentax-D FA* 50mm F1.4 SDM AW. It's not that "I need practise". I love f/1.2 but I wonder whether I am just a DA guy. All these focus callibrations and photoshop adjustments seem unnatural to me since I can today simply shoot, put the proper "lens profile" and have top images.

I got a used DA*55/1.4 instead of an A50/1.2. I've never tried the A50/1.2 so I just convinced myself that the DA* was a great choice. If you want shallow depth of field, they are the same. You can't brag about having an f1.2 lens. The DA* has all the cool modern features. It is an all weather lens. It used to be a big lens but the new 50mm lens makes it look small. I am very happy with the images. You should look at some samples first; it does have some fringing under certain conditions. The autofocus is normally slower than other new lenses, so it's maybe not awesome for street shooting.

[pepperberry farm]

I got a used DA*55/1.4 instead of an A50/1.2. I've never tried the A50/1.2 so I just convinced myself that the DA* was a great choice. If you want shallow depth of field, they are the same. You can't brag about having an f1.2 lens. The DA* has all the cool modern features. It is an all weather lens. It used to be a big lens but the new 50mm lens makes it look small. I am very happy with the images. You should look at some samples first; it does have some fringing under certain conditions. The autofocus is normally slower than other new lenses, so it's maybe not awesome for street shooting.

they are both great lenses, but different....

I've had all three at one point or another - and kept the DA* 55/1.4 and the K 50/1.2 for the images both produce....

[AfterPentax Mark II]

But this lens is manual focus not auto focus.

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...