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07-04-2011, 10:12 AM   #16
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QuoteOriginally posted by mr.sinha Quote
Hey deadwolf, I see you have the Panasonic GF1 too. I have it and love it, but ever since the K5 arrived, I haven't used it much :-(
Question for you, do you happen to know of a good 4/3 adapter to mount Pentax FA and DA lenses on the GF1?

Thanks.
Sure: I got one very much like this:

Pentax DA Lens 2 M4/3 Adapter Olympus E-P1 E-P2 E-PL2 | eBay

Works well, though I rarely use it.

07-04-2011, 11:50 AM   #17
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Due to the way the FA31 is constructed, some suffer from optical misalignment which impacts wide open sharpness greatly. However, the lack of sharpness can also be due to focus error. Below are 2 samples taken at f1.8 & f2.8. Will probably update with better shots later.

Tests Photo Gallery by Alan Chan at pbase.com
07-04-2011, 12:06 PM   #18
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After reading this thread, I decided to do the AF fine adjustment with my 31mm. I used the one here.

I ended up setting it to -10 to get optimal results. The shots definitely seem to look better. I also ended up checking out my other AF lenses, and they all needed some sort of adjustment.
07-04-2011, 04:56 PM   #19
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Thank you Sir. Will check it out.

07-04-2011, 07:56 PM   #20
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QuoteOriginally posted by mr.sinha Quote
Hello All,

I am a new member even though I have been a regular visitor of this forum for a while now. I am a K5 user and love it, and I bought a FA 31mm limited (yeah !!!... or so I thought) about a week ago.
I have been taking a lot of experimental pics at home to test out the lens, like putting at fixed position on a tripod, focussing on the fine print of a scotch bottle (black text on a white background) kept about 5 feet away, with single point focus, spot metering, M mode, manual focus etc. and I found that the lens is not as sharp at f/1.8 or f/2 , compared to the sharp-as-tack images that I got between f/4-f/5.6 range.
Question is, is this normal? Having read numerous reviews claiming that the fa31 has legendary sharpness even at 1.8, I must admit I am a tad disappointed with the results.
Or am I expecting too much? Or did I get a bad copy? Mine is an AIV one. I was thinking of returning it and getting another copy just to make sure, in case there are QC issue with the one I have.

Comments please.

Thanks.

I think it's in bad shape. I wouldn't mind buying it from you for $500.
07-05-2011, 05:54 AM   #21
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QuoteOriginally posted by Pentaxor Quote
I think it's in bad shape. I wouldn't mind buying it from you for $500.
How could I possibly sell you a bad lens?
07-05-2011, 06:57 AM   #22
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QuoteOriginally posted by mr.sinha Quote
How could I possibly sell you a bad lens?
because I'm cool !
07-05-2011, 08:23 AM   #23
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QuoteOriginally posted by mr.sinha Quote
Folks,
Is there any place in NYC where someone can professionally check and if necessary, do the AF tuning? I bought mine at B&H. In my whisky bottle tests indoors, at f/1.8, I went thru the whole range of AF adjustments (-10 to +10) but didn't notice much diff, so AF adjustment *may* not a problem here, but just want to rule it out.

Anyway, uploaded some photos on flickr from my shooting today. Light conditions were not optimal, sky was heavily overcast with light rain, but damn if I would sit at home shooting more fine prints on whisky bottles, so off I went, trying to protect the lens from rain as much as possible.

A walk in Central Park on a rainy day - a set on Flickr
Hi,
I think you should run a more controlled test.
First off, be aware that whiskey bottle doesn't affect a lens or camera but it does affect the tester.
Second, I'd recommend using one of the many focus charts.
Third, I'd be really concerned of my lens and/or camera if there was not much difference between -10 and +10 during AF adjustment, especially at F1.8.
Also, as others suggested, you need to post pictures to give people here an idea what you consider more sharp and less sharp.

In any case, happy shooting.

07-05-2011, 08:27 AM   #24
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Wide Open: Pentax 31 Limited & Leica 35 Summilux ASPH | STEVE HUFF PHOTOS
07-05-2011, 08:36 AM   #25
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Flawed test. The 31 is definitely not on the same focus plane as the Leica. The shots are OOF. This is where the brick wall test is worth doing.
07-05-2011, 10:05 AM   #26
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Indeed. From the 2nd, 3rd & 4th samples, the FA31 BF slightly. If they were MF, then the viewfinder needed calibration. I feel sorry the tester refused to acknowledge it and removed my comment.

Last edited by wlachan; 07-05-2011 at 12:29 PM.
07-05-2011, 08:22 PM   #27
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QuoteOriginally posted by wlachan Quote
Indeed. From the 2nd, 3rd & 4th samples, the FA31 BF slightly. If they were MF, then the viewfinder needed calibration. I feel sorry the tester refused to acknowledge it and removed my comment.
I agree. Read through the article and it definately looked out of focus. I don't own an FA31 but from what I have seen posted here at f/1.8 by a few different users the sharpness should be much better at f/1.8. It just looked OOF too.
It's a pity that the tester would not accept any criticism.
07-05-2011, 08:24 PM   #28
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QuoteOriginally posted by sinus007 Quote
Hi,
I think you should run a more controlled test.
First off, be aware that whiskey bottle doesn't affect a lens or camera but it does affect the tester.
Second, I'd recommend using one of the many focus charts.
Third, I'd be really concerned of my lens and/or camera if there was not much difference between -10 and +10 during AF adjustment, especially at F1.8.
Also, as others suggested, you need to post pictures to give people here an idea what you consider more sharp and less sharp.

In any case, happy shooting.

sinus007,

I swear I wasn't drinking the whisky while shooting it.

But you are right about the -10 to +10 range for AF adjustment, now that I look at the images. There is quite a bit of difference, and I think I need to set the AF adjustment somewhere around -5 for this lens (need more testing).

Attached are 6 pics of my whisky bottle test. All shot in A-mode, iso 200, with AF, subject about 4 feet away, camera on tripod. Shot in RAW, converted to JPEG in LR3 after cropping but no post processing.

#1(IMGP3326): f/1.8. AF adj +- 0.0
#2(IMGP3327): f/4. AF adj +- 0.0
#3(IMGP3328): f/1.8. AF adj -10.0
#4(IMGP3329): f/1.8. AF adj +10.0
#5(IMGP3330): f/1.8. AF adj -5.0
#6(IMGP3331): f/1.8. Af adj +5.0

Thanks.
Attached Images
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
07-06-2011, 06:06 AM   #29
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Perhaps it is just my eyes, but it seems to me that this bottle test may show the need for some - focus adjustment but may also tend to back up what Ben (Deadwolfbones) observed about AF inaccuracy in general. Since this is a curved bottle, it would seem to me that the edges (farther away) should be sharper or less sharp depending upon whether - or + adjustment is applied. There really doesn't appear to be a consistent difference to my old eyes.
07-06-2011, 07:01 AM   #30
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I suspect that's a substantial crop, right? 100%?

From the f/4 sample to the f/1.8 samples (all of them) the -5.0 is the best.

Try an f/8 as well.

Try with manual focus.
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