AF and focus accuracy using older firmware vs. new (1.03) on K5 plus DA*300

garyk · 05-09-2011, 06:00 AM

Thought i would keep you guys informed on my progress.
Taking you guys advice... I took the Sigma 300mm in to Sigma service. Good bunch of guys. The 300 alone is fine. What got me was the 300mm with the Sigma 1.4 T.C. is out.. But I rarely use the 1.4 T.C.
Had the lens rechipped last year. Didn't think about asking him if the K-5 is a different program than the K-x. The K-x was dead on... !
These are with the Pentax K-5 and Sigma 300mm F2.8.. at 2.8.. Will call him again tomorrow.

First pic 300mm f2.8.
Second pic 300mm + 1.4 T.C. f4.0

Attached Images

Last edited by garyk; 05-09-2011 at 06:10 AM.

**jpzk** · 05-10-2011, 06:53 PM

Originally posted by simico

?? What does sound waves have to do with light wavelength? Nothing.

It might have shaken the sensor?

JP

**jpzk** · 05-13-2011, 09:16 AM

Originally posted by garyk

Thought i would keep you guys informed on my progress.
Taking you guys advice... I took the Sigma 300mm in to Sigma service. Good bunch of guys. The 300 alone is fine. What got me was the 300mm with the Sigma 1.4 T.C. is out.. But I rarely use the 1.4 T.C.
Had the lens rechipped last year. Didn't think about asking him if the K-5 is a different program than the K-x. The K-x was dead on... !
These are with the Pentax K-5 and Sigma 300mm F2.8.. at 2.8.. Will call him again tomorrow.

First pic 300mm f2.8.
Second pic 300mm + 1.4 T.C. f4.0

Gary:

What is your camera set up when testing for FF/BF ... distance to target, ISO, aperture, type of lighting, etc?
Would you mind listing all of your settings for reference?

I did some tests on my other lenses but I find it rather akward when doing this with a 300mm tele. Nonetheless, I "think" there might be a bit of FF with my DA*300/4 when used with the K5.
Whether this has to do with the actual subject of this thread (AF with low contrast background and distant subjects) is what I am now wondering.

I was supposed to have the K5 sent to Pentax but when I was told that I should also ("must" they say) send the DA*300 along with it, I chikened out because I really need this lens at this time of the year and I have nowhere to go for a temporary replacement.
In the meantime, I am just trying to rule out anything else which can cause this problem.

Cheers.

JP

P.S.: I am going to add a few comments, questions and request for advice regarding a couple of more points later on this thread. I didn't want to start a new one just yet.

**jpzk** · 05-13-2011, 09:35 AM

Low contrast/distant subject and K5 AF ... cont'd:

Just as I was finishing a previous post here, regarding testing the lens/K5 for FF/BF, a few things came up in my ol' fried brains:

1. Does using TAv, which makes the camera choose its own ISO settings, affect in any way whatsoever the accuracy of the AF? Probably not, but I thought that if under some lighting conditions when the camera would pick ISO 1600 for instance, there could be some effect on the AF? Dumb but necessary question.

2. Would using Av instead, and dealing with the ISO myself to limit the upper settings, be more accurate? Again, likely not .... but I am not sure anymore.

3. What happens, or what is happening, when I try capturing a shot in this manner:

- blue, clear skies
- hawk hovering at a fair distance ... 30--400 feet away
- aim, using TAv, AF.S (most of the time)
- the focus indicator in ON, the beep is heard and the SR "hand" shows.
- press the shutter ... single shot or burst mode.

results: (not consistently) the bird is totally out of focus.

The situation is much worse when I try taking a shot, even at a reasonable distance, when the background is "blending" somewhat with the subject, i.e.: a brown hawk against a beige-brownish background.

I know this will sound like I am trying the impossible, but then why is this much better when I use(d) my K20D, with that same lens?

So, back to testing the FF/BF possibilities this weekend indoors and, wheather permitting, outside.

Cheers.

JP

**jbinpg** · 05-13-2011, 12:07 PM

Something is wrong, JP. I take hawks in flight shots using TAv and AF.S on centrepoint focus with my DA*300 all the time and they are in focus, even at great distance..

Jack

**jpzk** · 05-13-2011, 12:35 PM

Originally posted by jbinpg

Something is wrong, JP. I take hawks in flight shots using TAv and AF.S on centrepoint focus with my DA*300 all the time and they are in focus, even at great distance..

Jack

That's what I think too

Of course, I want to try everything possible before departing from my gear for at least 3 to 4 weeks!
Bad time of the year for that.

JP

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05-09-2011, 06:00 AM	#61
garyk Inactive Account Join Date: Feb 2010 Photos: Gallery Posts: 488	Thought i would keep you guys informed on my progress. Taking you guys advice... I took the Sigma 300mm in to Sigma service. Good bunch of guys. The 300 alone is fine. What got me was the 300mm with the Sigma 1.4 T.C. is out.. But I rarely use the 1.4 T.C. Had the lens rechipped last year. Didn't think about asking him if the K-5 is a different program than the K-x. The K-x was dead on... ! These are with the Pentax K-5 and Sigma 300mm F2.8.. at 2.8.. Will call him again tomorrow. First pic 300mm f2.8. Second pic 300mm + 1.4 T.C. f4.0 Attached Images Last edited by garyk; 05-09-2011 at 06:10 AM.

05-10-2011, 06:53 PM	#62
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251 Original Poster	Originally posted by simico ?? What does sound waves have to do with light wavelength? Nothing. It might have shaken the sensor? JP

05-13-2011, 09:16 AM	#63
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251 Original Poster	Originally posted by garyk Thought i would keep you guys informed on my progress. Taking you guys advice... I took the Sigma 300mm in to Sigma service. Good bunch of guys. The 300 alone is fine. What got me was the 300mm with the Sigma 1.4 T.C. is out.. But I rarely use the 1.4 T.C. Had the lens rechipped last year. Didn't think about asking him if the K-5 is a different program than the K-x. The K-x was dead on... ! These are with the Pentax K-5 and Sigma 300mm F2.8.. at 2.8.. Will call him again tomorrow. First pic 300mm f2.8. Second pic 300mm + 1.4 T.C. f4.0 Gary: What is your camera set up when testing for FF/BF ... distance to target, ISO, aperture, type of lighting, etc? Would you mind listing all of your settings for reference? I did some tests on my other lenses but I find it rather akward when doing this with a 300mm tele. Nonetheless, I "think" there might be a bit of FF with my DA300/4 when used with the K5. Whether this has to do with the actual subject of this thread (AF with low contrast background and distant subjects) is what I am now wondering. I was supposed to have the K5 sent to Pentax but when I was told that I should also ("must" they say) send the DA300 along with it, I chikened out because I really need this lens at this time of the year and I have nowhere to go for a temporary replacement. In the meantime, I am just trying to rule out anything else which can cause this problem. Cheers. JP P.S.: I am going to add a few comments, questions and request for advice regarding a couple of more points later on this thread. I didn't want to start a new one just yet.

05-13-2011, 09:35 AM	#64
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251 Original Poster	Low contrast/distant subject and K5 AF ... cont'd: Just as I was finishing a previous post here, regarding testing the lens/K5 for FF/BF, a few things came up in my ol' fried brains: 1. Does using TAv, which makes the camera choose its own ISO settings, affect in any way whatsoever the accuracy of the AF? Probably not, but I thought that if under some lighting conditions when the camera would pick ISO 1600 for instance, there could be some effect on the AF? Dumb but necessary question. 2. Would using Av instead, and dealing with the ISO myself to limit the upper settings, be more accurate? Again, likely not .... but I am not sure anymore. 3. What happens, or what is happening, when I try capturing a shot in this manner: - blue, clear skies - hawk hovering at a fair distance ... 30--400 feet away - aim, using TAv, AF.S (most of the time) - the focus indicator in ON, the beep is heard and the SR "hand" shows. - press the shutter ... single shot or burst mode. results: (not consistently) the bird is totally out of focus. The situation is much worse when I try taking a shot, even at a reasonable distance, when the background is "blending" somewhat with the subject, i.e.: a brown hawk against a beige-brownish background. I know this will sound like I am trying the impossible, but then why is this much better when I use(d) my K20D, with that same lens? So, back to testing the FF/BF possibilities this weekend indoors and, wheather permitting, outside. Cheers. JP

05-13-2011, 12:07 PM	#65
jbinpg Site Supporter Join Date: Mar 2008 Location: Prince George, BC Photos: Gallery \| Albums Posts: 3,546	Something is wrong, JP. I take hawks in flight shots using TAv and AF.S on centrepoint focus with my DA*300 all the time and they are in focus, even at great distance.. Jack

05-13-2011, 12:35 PM	#66
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251 Original Poster	Originally posted by jbinpg Something is wrong, JP. I take hawks in flight shots using TAv and AF.S on centrepoint focus with my DA*300 all the time and they are in focus, even at great distance.. Jack That's what I think too Of course, I want to try everything possible before departing from my gear for at least 3 to 4 weeks! Bad time of the year for that. JP