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12-19-2013, 06:09 PM   #16
npc
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If autofocus was the problem you would have the same rate of out of focus pictures with flash or without flash. Autofocus process is exactly the same in both cases.
Maybe the camera was picking too slow speeds and also shooting the lens wide open without the flash. At least this is what it looks like from the 2 posted images:
soft image: 1/3s iso 800 f 4.5 48mm
sharp image: 1/100s iso 100 f 6.3 40mm

12-19-2013, 06:54 PM   #17
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QuoteOriginally posted by npc Quote
and also shooting the lens wide open without the flash
= less DOF, requiring more accurate AF
12-19-2013, 07:33 PM   #18
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QuoteOriginally posted by npc Quote
If autofocus was the problem you would have the same rate of out of focus pictures with flash or without flash. Autofocus process is exactly the same in both cases.
Maybe the camera was picking too slow speeds and also shooting the lens wide open without the flash. At least this is what it looks like from the 2 posted images:
soft image: 1/3s iso 800 f 4.5 48mm
sharp image: 1/100s iso 100 f 6.3 40mm
Sorry. I posted the soft image just as an example representing the most sharpness I was able to obtain before adjustment out of 410 images. I didn't realize all the exif info could be interpreted to a different conclusion. I could post more, may be after I transfer the image to a cdn (distributed network) for faster loading. I will definitely post at least one more image where I realized the issue of spot af point focusing something in the back.

Now that you have pointed out the photo's exif, that particular soft image was probably taken on a tripod.
12-19-2013, 07:36 PM   #19
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QuoteOriginally posted by penmar Quote
solved. But, the cost is too high for what I get. Half a pound & 1cm in body size saving for $700 more? With a less sharp sensor (according to DXO comparison) and smaller zoom range (12-40 pro zoom vs 18-135)? No thanks.
Just an FYI, the 12-40 is an f/2.8 lens...which is a fast zoom. Shorter/smaller zoom range generally = sharper.
The 18-135 is good, but I doubt it's as good as that 12-40 lens...

Glad you're exchanging and Adorama is taking care of you. This does happen...usually w/ Sigma/Tamron lenses though :-)

12-19-2013, 07:54 PM - 2 Likes   #20
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Make sure you have the high ISO noise reduction turned off...watch this video by Ed from photouniverse
in it he explains the problems that he was having with out of focus images when the high ISO noise reduction was set to automatic.
12-19-2013, 09:05 PM   #21
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Just a thought - if you had the AA simulator off AND used a tripod AND used MLU to eliminate any shake and flash still rendered sharper images, it makes one wonder if your camera is holding the sensor dead still. Try turning the shake reduction off and try again? If flash *still* makes it sharper, there has to be a movement problem.
12-19-2013, 09:55 PM   #22
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QuoteOriginally posted by c.a.m Quote
...
Hope you got something out of the hours of on-line video! By the way, welcome to Pentax Forums.

Craig
Thank you Craig. I definitely did learn a lot more from the videos. Being new to a field is sometimes a good thing because I don't know what is customary and what is not. Now, at least I learned lens calibration quick . All the video seminars from B&H on YouTube are great!

QuoteOriginally posted by kenyee Quote
Just an FYI, the 12-40 is an f/2.8 lens...which is a fast zoom. Shorter/smaller zoom range generally = sharper.
Makes me wonder in a case like this, which image would be sharper. Well, I'm sure there are so many factors & variables, such as color vibrancy for instance, that are unique to individual. Probably too hard to tell. That's why I avoid making my living with art. Too subjective. I love the sure thing. Is it fixed? Yes? Now, pay me .

QuoteOriginally posted by fwbigd Quote
Make sure you have the high ISO noise reduction turned off...watch this video by Ed from photouniverse Pentax K-3: REDEMPTION - YouTube in it he explains the problems that he was having with out of focus images when the high ISO noise reduction was set to automatic.
Yes. I have watched this video and because of that, for the last few days of testing, it was off for the majority of the time. Thanks.

QuoteOriginally posted by phreon Quote
Just a thought - if you had the AA simulator off AND used a tripod AND used MLU to eliminate any shake and flash still rendered sharper images, it makes one wonder if your camera is holding the sensor dead still. Try turning the shake reduction off and try again? If flash *still* makes it sharper, there has to be a movement problem.
AA was never switched on since I've gotten it. I don't think I have any test picture taken with "tripod & flash" used together. Too late to try. It went back. Hopefully, my new one is perfect. If not, I will definitely try every idea on this thread . Thanks.

Last edited by penmar; 12-19-2013 at 10:19 PM.
12-19-2013, 10:31 PM   #23
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Whew!

I just tested this using my 35mm f/2.4.

On the tripod both OVF and Live View shots were tack sharp.

Handheld the OVF shots were tack sharp (at 0.3 second) but the Live View shots were blurred - as you would expect since the OVF shots had the camera shoved up against my face and the Live View shots were held out at a distance.

I guess this is a good test for people to perform out of the box - just glad after a month with the K-3 mine was okay. I am very impressed with this camera. I thought it would be tough to improve on the K-5 but they've done it.

12-20-2013, 07:02 AM   #24
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this link might be helpful if you are looking to test calibrate the AF....
Jeffrey Friedl's Blog
12-20-2013, 10:40 AM   #25
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Can you elaborate where your terms and figures come from and what you mean by them?
As a professional statistician I’m asking myself: Standard deviation of what?

QuoteQuote:
Six Sigma is 0.000004

Last edited by Alfie; 12-20-2013 at 12:27 PM. Reason: typo
12-20-2013, 10:53 AM   #26
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QuoteOriginally posted by Alfie Quote
Standard deviation of what?
Good question. The conventional answer is "the mean". But in this case, the 4% is the mean!


Steve
12-20-2013, 04:39 PM   #27
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QuoteOriginally posted by npc Quote
If autofocus was the problem you would have the same rate of out of focus pictures with flash or without flash. Autofocus process is exactly the same in both cases.
Maybe the camera was picking too slow speeds and also shooting the lens wide open without the flash. At least this is what it looks like from the 2 posted images:
soft image: 1/3s iso 800 f 4.5 48mm
sharp image: 1/100s iso 100 f 6.3 40mm
those numbers came from the raw files? that would make sense, 1/3s(?) would require good technique to hold the camera steady, even with sr on... using manual settings is something for the o.p. to consider, even with the autofocus fixed.

penmar, you did a good job of describing and troubleshooting the issue, you could have a career in i.t. support... er, wait, you already do that?

I ended up getting one of those a7r's you mentioned, it's an incredible camera, but for where you are at, and best bang for the buck, k-3 is the better choice... this a7r feels like a farking throwaway toy, i'm skeptical about the long term durability... some people have returned it, because they claim that it has shutter shock under certain circumstances; the flagship sony flash has overheating issues, etc.

the k-3 probably has a magnify function, when it's in live view mode on the lcd display? learn how to use that to confirm focus, it's more accurate than autofocus.
12-20-2013, 10:19 PM   #28
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QuoteOriginally posted by osv Quote
penmar, you did a good job of describing and troubleshooting the issue, you could have a career in i.t. support ... er, wait, you already do that?
Thanks. Yup. 14 years in computer consulting. Most people who came to me are in super "sticky" situations, like security breaches or publicized government/corporation mergers/takeovers that needed face-saving on national media. That's why I'm a handyman; I only get called when things aren't working. So, jumping in (praying ), assessing situation, learning quick, and troubleshooting is a must in my field.

QuoteQuote:
.. this a7r feels like a farking throwaway toy, i'm skeptical about the long term durability
May be you got elevated expectations on durability after using Pentax cameras . The K-3 I got felt so solid. I imagine all Pentax cameras are like that. For me, even though I bought the K-3 untouched and unseen, the soldier Pentax video sold me in terms of durability.

QuoteQuote:
the k-3 probably has a magnify function, when it's in live view mode on the lcd display? learn how to use that to confirm focus, it's more accurate than autofocus.
I think so. I haven't really used the live view that much. Probably less than 10 pictures taken with it. The truth is I haven't really read the manual at all. Must be the acclaimed Pentax ergonomics. Things just make sense and I just started shooting . When my replacement gets here, I will definitely try it out. Thanks.

Last edited by penmar; 12-21-2013 at 01:03 PM.
12-21-2013, 03:36 PM   #29
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QuoteOriginally posted by penmar Quote
May be you got elevated expectations on durability after using Pentax cameras . The K-3 I got felt so solid. I imagine all Pentax cameras are like that. For me, even though I bought the K-3 untouched and unseen, the soldier Pentax video sold me in terms of durability.
that k-3 should last you a good long time!

when I opened the a7r box and looked in, before I even picked the camera up, my first thought was, "what the heck did I just spend $2,300 on!!", followed by a wave of regret

this thing looks like something you'd give your kids to play with; people(including me) are afraid to hang big lenses off of it... I immediately ordered a second pka adapter, because the first one I got didn't have a tripod mount on it.

the full frame situation is proving to be discouraging when it comes to using my old wide prime lenses, because there are so many faults in the area outside of the crop sensor field of view... what would have been acceptable on the k-3 is marginal on the a7r.

anyway, post up some pics when you get that thing dialed in!
12-23-2013, 08:23 AM   #30
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In regards to the original post- I can't emphasize enough the importance of verifying and performing an AF Fine Focus Adjustment on the Pentax DSLR's based on my personal experience with a K-5 which was quite similar to the original poster. The results can be significant in regards to accurate (front vs rear) focusing, focus accuracy and consistency (in the case of the K-5), and overall image resolution. The OEM end of production tolerance for AF adjustment is far too broad to ensure accurate results and should be verified and optimized for each camera body to lens combination.

[Disclaimer: This process can be done in various ways. However- I feel obligated to acknowledge it can be a major pain (e.g. can be difficult to judge or find consistency within itself)].
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