What is this %$&#?* (No. 1)?

bxf · 02-18-2011, 05:12 AM

Originally posted by Adam

It would be helpful if EXIF info wasn't stripped from the photos!

Hmmm, PhotoMe shows all EXIF info for the pics I've uploaded, so I suppose it was lost during the upload process? How do I upload and retain EXIF data?

30v iPentax · 02-18-2011, 06:06 AM

Ehkä yli valottuneita.

bxf · 02-18-2011, 10:27 PM

Originally posted by 30v iPentax

Ehkä yli valottuneita.

That issue I will tackle in a future What is this %$&#?* (No. 2)?, unless I manage to find some answers in existing threads).
Edit: I've seen several threads with references to flash overexposure, and also the statement blurred images when using PTTL flash at 1/125 to 1/160second, which sounds like something I have too, though I haven't actually narrowed it down to a specific shutter speed range. I have suspected that some of the horrible results I've obtained are due to poor flash performance, compounding the FF issue.

30v iPentax · 02-19-2011, 02:12 AM

Se on ehkä Google huono kielen ymmärrys.

SteveM · 02-19-2011, 02:33 AM

After reading the issues, the responses, and your reply, I would recommend a good photography book. Something that covers exposure, composition, lighting, focal length, etc. Pentax / Canon / Nikon, it won't help you with those type of issues.

mgm2 · 02-19-2011, 07:46 AM

Just curious have you tried additional shots with similar lighting and are they in or out of focus?

Smeggypants · 02-19-2011, 12:20 PM

Originally posted by bxf

...it sounds like it could be the artificial light FF problem after all. I was under the impression that the FF error was in the range of a few centimeters, but evidently that is not the case. I must agree with those who take a strong stance on this issue, as it presents severe limitations.

.

Nope it's not the case from ....

https://www.pentaxforums.com/forums/1382765-post59.html

Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4

1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet

Auto Focussing using Live view

Auto Focussing using regular focus

btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it.

And of course the K-5 can take low light photos. I've taken hundreds of them already.

Christine Tham · 02-20-2011, 03:20 PM

It seems the guys on this forum are probably too polite to comment, but I'll say it ...

the girl in those photos look totally hawt!!! great body and legs!

My thoughts on the photos - the glitter in her skirt and her hair strands seem focused to me ... (hard to tell though due to the reduced resolution)

are you sure you are not taking those photos with your lenses wide open? generally lenses look a bit soft when they are not stopped down a bit.

I probably would have used f4 or even f5.6 for those photos.

bxf · 02-21-2011, 01:18 PM

Originally posted by smc

After reading the issues, the responses, and your reply, I would recommend a good photography book. Something that covers exposure, composition, lighting, focal length, etc. Pentax / Canon / Nikon, it won't help you with those type of issues.

Sounds good. Now, if you could only direct me to a publication that discusses K5 low-light focusing problems in detail, that would be most helpful.

bxf · 02-21-2011, 01:40 PM

Originally posted by mgm2

Just curious have you tried additional shots with similar lighting and are they in or out of focus?

Yes, and yes. I'm taking my time replying to these posts because I'm away on holiday, with limited internet time and limited time to perform meaningful experiments with the K5. But, although most of what I've been doing is taking snapshots, many are in relatively low light, with out of focus results. Daylight shots are definitely better, confirming the suspicion that this is "simply" the K5 low light problem.

bxf · 02-21-2011, 02:10 PM

Originally posted by Smeggypants

Nope it's not the case from ....

https://www.pentaxforums.com/forums/1382765-post59.html

Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4

1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet

Auto Focussing using Live view

Auto Focussing using regular focus

btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it.

And of course the K-5 can take low light photos. I've taken hundreds of them already.

I'm encountering problems similar to what you've shown. As you point out, it appears that the focusing problems are not restricted to very low light.

Unfortunately, I'm having problems with live view, where sometimes it simply will not focus (neither phase nor contrast). I must chase that one down separately.

By the way, do you happen to know the effective range of the AF Assist beam? It seems that my K5 will not focus when pointed to some dim areas, even though the beam comes on, and is visible on the target area (though faintly).

bxf · 02-21-2011, 02:16 PM

Originally posted by Christine Tham

It seems the guys on this forum are probably too polite to comment, but I'll say it ...

the girl in those photos look totally hawt!!! great body and legs!

My thoughts on the photos - the glitter in her skirt and her hair strands seem focused to me ... (hard to tell though due to the reduced resolution)

are you sure you are not taking those photos with your lenses wide open? generally lenses look a bit soft when they are not stopped down a bit.

I probably would have used f4 or even f5.6 for those photos.

Ha, you should see her when she's in focus

Thanks for the comment.

I don't think I agree about the glitter and hair being in focus. I have other shots where they are, and the difference is clear.

Some of the shots were taken wide open (why is there no EXIF for these things? It is present on the pics I uploaded), but I have several taken a stop down, and they are still OOF, though in some cases less severely, probably due to greater DOF.

Wheatfield · 02-21-2011, 02:19 PM

Originally posted by Smeggypants

Nope it's not the case from ....

https://www.pentaxforums.com/forums/1382765-post59.html

Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4

1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet

Auto Focussing using Live view

Auto Focussing using regular focus

btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it.

And of course the K-5 can take low light photos. I've taken hundreds of them already.

You do realize that your example is ~EV2, which would be considered low light by pretty much anyone.

Christine Tham · 02-21-2011, 05:12 PM

Originally posted by bxf

I don't think I agree about the glitter and hair being in focus. I have other shots where they are, and the difference is clear.

Some of the shots were taken wide open (why is there no EXIF for these things? It is present on the pics I uploaded), but I have several taken a stop down, and they are still OOF, though in some cases less severely, probably due to greater DOF.

I understand that you would have taken several shots, and some came out better than others.

It's just that I'm not necessarily seeing FF in those photos, just blurriness which could be due to a number of factors.

My experience is that taking flash photos with the lens wide open may cause results like your examples, regardless of whether the camera has good focus or not.

Not saying that your camera doesn't have the issue, just saying it's hard to tell because there may be other factors.

In a situation like that, I would be tempted to not use the flash, and take a photo at f5.6 and use high ISO. I would be tempted to process it as B&W - she would look absolutely ravishing rendered in B&W I think. Just a suggestion.

bxf · 02-23-2011, 10:44 AM

Originally posted by Christine Tham

I understand that you would have taken several shots, and some came out better than others.

It's just that I'm not necessarily seeing FF in those photos, just blurriness which could be due to a number of factors.

Hence the title of my post - I really did/do not know what is going on. Some of my shots look so strange that I've been reluctant to assume it was just a focusing error issue. For example, I have two shots, taken 9 seconds apart, of virtually the same subject, using the builtin flash, and with a difference of probably several stops in the flash output. I'm also having difficulty pinning down the behaviour of the AF Assist beam, which seems to behave inconsistently.

Having said that, I can't do any meaningful tests or adjustments until I get back home from holiday early next month, at which time I expect I'll be raising some issues with more specific and accurate info.

Thanks for your input.

02-18-2011, 10:27 PM	#18
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by 30v iPentax Ehkä yli valottuneita. That issue I will tackle in a future What is this %$&#? (No. 2)?, unless I manage to find some answers in existing threads). Edit: I've seen several threads with references to flash overexposure, and also the statement blurred images when using PTTL flash at 1/125 to 1/160second, which sounds like something I have too, though I haven't actually narrowed it down to a specific shutter speed range. I have suspected that some of the horrible results I've obtained are due to poor flash performance, compounding the FF issue. Last edited by bxf; 02-21-2011 at 02:02 PM. Reason: New info found*

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02-18-2011, 05:12 AM	#16
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Adam It would be helpful if EXIF info wasn't stripped from the photos! Hmmm, PhotoMe shows all EXIF info for the pics I've uploaded, so I suppose it was lost during the upload process? How do I upload and retain EXIF data?

02-18-2011, 06:06 AM	#17
30v iPentax Inactive Account Join Date: Apr 2010 Location: Suomi , Finland Posts: 368	Ehkä yli valottuneita.

02-19-2011, 02:12 AM	#19
30v iPentax Inactive Account Join Date: Apr 2010 Location: Suomi , Finland Posts: 368	Se on ehkä Google huono kielen ymmärrys.

02-19-2011, 02:33 AM	#20
SteveM Veteran Member Join Date: Jan 2009 Location: Vancouver Island, BC, Canada Photos: Gallery Posts: 3,294	After reading the issues, the responses, and your reply, I would recommend a good photography book. Something that covers exposure, composition, lighting, focal length, etc. Pentax / Canon / Nikon, it won't help you with those type of issues.

02-19-2011, 07:46 AM	#21
mgm2 New Member Join Date: Sep 2009 Location: Pennsylvania Posts: 22	Just curious have you tried additional shots with similar lighting and are they in or out of focus?

02-19-2011, 12:20 PM	#22
Smeggypants Veteran Member Join Date: Sep 2010 Posts: 1,536	Originally posted by bxf ...it sounds like it could be the artificial light FF problem after all. I was under the impression that the FF error was in the range of a few centimeters, but evidently that is not the case. I must agree with those who take a strong stance on this issue, as it presents severe limitations. . Nope it's not the case from .... https://www.pentaxforums.com/forums/1382765-post59.html Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4 1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet Auto Focussing using Live view Auto Focussing using regular focus btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it. And of course the K-5 can take low light photos. I've taken hundreds of them already.

02-20-2011, 03:20 PM	#23
Christine Tham Veteran Member Join Date: Nov 2008 Location: Sydney, Australia Photos: Gallery Posts: 2,269	It seems the guys on this forum are probably too polite to comment, but I'll say it ... the girl in those photos look totally hawt!!! great body and legs! My thoughts on the photos - the glitter in her skirt and her hair strands seem focused to me ... (hard to tell though due to the reduced resolution) are you sure you are not taking those photos with your lenses wide open? generally lenses look a bit soft when they are not stopped down a bit. I probably would have used f4 or even f5.6 for those photos.

02-21-2011, 01:18 PM	#24
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by smc After reading the issues, the responses, and your reply, I would recommend a good photography book. Something that covers exposure, composition, lighting, focal length, etc. Pentax / Canon / Nikon, it won't help you with those type of issues. Sounds good. Now, if you could only direct me to a publication that discusses K5 low-light focusing problems in detail, that would be most helpful.

02-21-2011, 01:40 PM	#25
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by mgm2 Just curious have you tried additional shots with similar lighting and are they in or out of focus? Yes, and yes. I'm taking my time replying to these posts because I'm away on holiday, with limited internet time and limited time to perform meaningful experiments with the K5. But, although most of what I've been doing is taking snapshots, many are in relatively low light, with out of focus results. Daylight shots are definitely better, confirming the suspicion that this is "simply" the K5 low light problem.

02-21-2011, 02:10 PM	#26
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Smeggypants Nope it's not the case from .... https://www.pentaxforums.com/forums/1382765-post59.html Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4 1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet Auto Focussing using Live view Auto Focussing using regular focus btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it. And of course the K-5 can take low light photos. I've taken hundreds of them already. I'm encountering problems similar to what you've shown. As you point out, it appears that the focusing problems are not restricted to very low light. Unfortunately, I'm having problems with live view, where sometimes it simply will not focus (neither phase nor contrast). I must chase that one down separately. By the way, do you happen to know the effective range of the AF Assist beam? It seems that my K5 will not focus when pointed to some dim areas, even though the beam comes on, and is visible on the target area (though faintly).

02-21-2011, 02:16 PM	#27
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Christine Tham It seems the guys on this forum are probably too polite to comment, but I'll say it ... the girl in those photos look totally hawt!!! great body and legs! My thoughts on the photos - the glitter in her skirt and her hair strands seem focused to me ... (hard to tell though due to the reduced resolution) are you sure you are not taking those photos with your lenses wide open? generally lenses look a bit soft when they are not stopped down a bit. I probably would have used f4 or even f5.6 for those photos. Ha, you should see her when she's in focus Thanks for the comment. I don't think I agree about the glitter and hair being in focus. I have other shots where they are, and the difference is clear. Some of the shots were taken wide open (why is there no EXIF for these things? It is present on the pics I uploaded), but I have several taken a stop down, and they are still OOF, though in some cases less severely, probably due to greater DOF.

02-21-2011, 02:19 PM	#28
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	Originally posted by Smeggypants Nope it's not the case from .... https://www.pentaxforums.com/forums/1382765-post59.html Here's two images taken by myself ( not something I've randomly lifted of the Net ) of the same number plate with my K-5 with attached Sigma 30mm/1.4 1/160 f/1.6 ISO6400 - both 100% crops. no PP - subject distance about 20 to 25 feet Auto Focussing using Live view Auto Focussing using regular focus btw - that number plate wasn't even dim light, it was lit by the headlights of my car. K-5's regular AF failed. Live view focus nailed it. And of course the K-5 can take low light photos. I've taken hundreds of them already. You do realize that your example is ~EV2, which would be considered low light by pretty much anyone.

02-21-2011, 05:12 PM	#29
Christine Tham Veteran Member Join Date: Nov 2008 Location: Sydney, Australia Photos: Gallery Posts: 2,269	Originally posted by bxf I don't think I agree about the glitter and hair being in focus. I have other shots where they are, and the difference is clear. Some of the shots were taken wide open (why is there no EXIF for these things? It is present on the pics I uploaded), but I have several taken a stop down, and they are still OOF, though in some cases less severely, probably due to greater DOF. I understand that you would have taken several shots, and some came out better than others. It's just that I'm not necessarily seeing FF in those photos, just blurriness which could be due to a number of factors. My experience is that taking flash photos with the lens wide open may cause results like your examples, regardless of whether the camera has good focus or not. Not saying that your camera doesn't have the issue, just saying it's hard to tell because there may be other factors. In a situation like that, I would be tempted to not use the flash, and take a photo at f5.6 and use high ISO. I would be tempted to process it as B&W - she would look absolutely ravishing rendered in B&W I think. Just a suggestion.

02-23-2011, 10:44 AM	#30
bxf Veteran Member Join Date: Jul 2010 Location: Lisbon area Posts: 1,660 Original Poster	Originally posted by Christine Tham I understand that you would have taken several shots, and some came out better than others. It's just that I'm not necessarily seeing FF in those photos, just blurriness which could be due to a number of factors. Hence the title of my post - I really did/do not know what is going on. Some of my shots look so strange that I've been reluctant to assume it was just a focusing error issue. For example, I have two shots, taken 9 seconds apart, of virtually the same subject, using the builtin flash, and with a difference of probably several stops in the flash output. I'm also having difficulty pinning down the behaviour of the AF Assist beam, which seems to behave inconsistently. Having said that, I can't do any meaningful tests or adjustments until I get back home from holiday early next month, at which time I expect I'll be raising some issues with more specific and accurate info. Thanks for your input.