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01-18-2008, 05:18 AM   #16
mer
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so what are you trying to tell us pentagor ?

That the focus confirmation isn't 100% accurate ?

That when you focus with your eyes and then take picture the focus point changes ?

I don't understand... and yes I have owned the F1.7 and I still have my f1.4 .

01-18-2008, 05:27 AM   #17
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QuoteOriginally posted by mer Quote
so what are you trying to tell us pentagor ?

That the focus confirmation isn't 100% accurate ?

That when you focus with your eyes and then take picture the focus point changes ?
Exactly! But only at F/1.7! And I'm not the only one with this problem. See the post by fastoys2nv and truonganh. It could be, that the human eye doesn't focus very good at low light, but it still is an issue.
01-18-2008, 05:51 AM   #18
mer
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Exactly what ?

Are you saying that when you focus with your eyes and then take picture the focus point changes ?

You know this cant be true right ?

Yes I know its kinda difficult to focus with fast lenses ( as I said I own the f1.4 ) but where I focus , this is where the picture is taken . A different focussing screen can help .

We all know that the focus indicator ... is just an indicator and not 100% accurate but it works pretty good in contrasty well-lit objects and some times is spot on.

When I first got my F1.4 I would swear I had a perfect focus when I took the picture but when I reviewed at 100% crop it was clearly not . But now my focussing skills are way better and most of the time I can focus correctly .
01-18-2008, 06:28 AM   #19
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I was trying to point out it could be an issue with the camera. It is just very noticeable at f1.7. I had the focus indicator and my focus point was the center can and it was in focus to my eye. Focus issues just seam to be amplified by manual focus and shallow DOF.

01-18-2008, 06:47 AM   #20
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QuoteOriginally posted by pentagor Quote
Sorry creampuff, but I don't agree with you. After your first post, I beleived you, but then I tried to trust my eyes and nothing changed. Still frontfocus. Don't tell me to adjust my eyes or get diopter correction fixed, 'cause I did all that too.
And since I'm not the only one, one question for you: Do you own a 50/1.7 M lense?
I have a A 50 f/1.7, FA 50 f/1.4, FA 50 f/2.8 Macro & M 40 f/2.8 among many other manual focus lenses of differing focal length and max apertures. Throw in a Lensbaby as well. Never had any problems focusing manually with any of my lenses. I'm right now using a Sigma 90mm f/2.8 Macro which is a great MF lens with no issues focusing wise.

Honestly, if you're focusing manually, do you really need the camera to confirm focus or do you rely with what your eye sees in the viewfinder.
01-18-2008, 07:24 AM   #21
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my eye and the camera were both telling that the object was in focus. Any you can see by the results it was not. I am going to repeat the test today with the new body and see if it was a camera issue as I suspected.
01-18-2008, 09:17 AM   #22
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ok test 2 with the 50 f1.7 same lens, New K100D body, Same location, Focus by eye and indicator looked accurate

photo is cropped to show focus, again center can was the focus point @ 1.7

01-18-2008, 10:17 AM   #23
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Looks like it is spot on. Be happy and go take some pictures!

01-18-2008, 03:11 PM   #24
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Hi
This thread at Manual Focus Forum will help. I ma still working on it!!!

Manual Focus Forum / Super Tak 50 1.1:4 focus
01-18-2008, 07:02 PM   #25
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Hi, I'm new in this forum and this is my first thread.
In fact, I just signed up few minutes ago , but I've been reading the threads here and it's really helpful.
Regarding Pentagor's frontfocusing problem. I just got my A 50mm f/1.7 last week. And last night when I was playing with it, I experienced the same problem.

In the past, I had the same problem with my 43 Ltd and somebody from DPR forum guide me on how to set our focusing problem by ourselves through the debug menu. That saves me a lot of trouble since I don't have worry anymore with any focusing problem.
What I did is if I found a lens doesn't focus on spot, I'll adjust the camera so it will be spot on.
The only drawback is, I need to remember the setting of every lens that has focus problem.
It's not a big deal for me, since I just have to adjust once.

I'm sure you all already know how to adjust the focus from your camera that I was talking about. But in case anybody don't, pls feel free to ask me and I'll be glad to post it here.

Have fun.
01-22-2008, 05:26 PM   #26
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FYI: this link below was performed on a *ist DS. Ricehigh, the author, is a highly technical critics of the Pentax d-slr system. he posts stuff around here all the time.

Pentax *ist DS AF Dependency on Kelvin & Exposure Value

Last edited by truonganh; 01-22-2008 at 05:33 PM.
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