Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Jan 2, 2012, 3:51 PM   #1
Senior Member
 
Catbells's Avatar
 
Join Date: Nov 2004
Posts: 874
Default K5 Auto White Balance Issues in Panoramas

I like to compose a panoramic view by taking a sequence of images which I stitch together in Photoshop. With previous cameras Pentax *istDS & K10, I've simply composed the 1st shot, pressed the AE-L button to lock the exposure, switch to Manual Focus and then take the required number of shots for the Panoramic view. It worked fine, 99.99% of the time with hardly any issues.

I bought the K5 and immediately hit problems with locking the exposure using the AE-L button - basically, it didn't always work and gave differing exposures during the sequence of shots. It was suggested here that I use Manual Mode, press the green button to set the exposure, fine tune aperture/shutter speed and take the required sequence of shots - seemed to work fine on the dull day that composed about 6 panoramas with aperture and shutter speed locked.

Today, on a bright day, another problem has emerged i.e. White Balance. Having set the camera up on Manual Mode a sequence of shots were taken all with same aperture and shutter speed which on the face of it, should have enough BUT, White Balance is difference across all shots.

I have Lightroom, so I can manually change the White Balance of each shot to be the same but I seem to fighting the K5's limitations in this respect; I don't feel in control - it's another thing that I have to find a way around.

I can only assume that with the *istDs/K10, when you locked the exposure, it also locked the White Balance - certainly when I look back and check exposures of K10 panoramas, not only is the aperture and Shutter speed the same, the white balance is as well.

Any suggestions on how to achieve my goal by locking aperture, shutter speed (exposure) and locking the White Balance to ensure that when the sequence of shots are stitched together that they all blend together.

It's hard to see the problem with the attached images, but the central part of the 1st one has a brigher blue area of sky.
Attached Images
  
__________________
Pentax K10/K5, DA18-55mm, DA50-200mm & Tamrom 18-250mm
Catbells is offline   Reply With Quote
Sponsored Links
Old Jan 2, 2012, 10:26 PM   #2
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,056
Default

Two possible solutions (which really are related) come to mind. I assume you are using auto WB - I find the WB on the K5 pretty good but it once in a while makes mistakes, and it can make slight changes as conditions change (noticed that today). One way to deal with that is to set the WB to daylight under bright conditions, or else set a custom white balance for the particular conditions. If WB is critical, like here, I'd set a custom white balance.
mtngal is offline   Reply With Quote
Old Jan 2, 2012, 11:29 PM   #3
Senior Member
 
Frogfish's Avatar
 
Join Date: Feb 2006
Location: Shanghai, China
Posts: 2,774
Default

Shoot in RAW !
__________________
http://frogfish.smugmug.com
Pentax : 15 Ltd, 77 Ltd, 43/1.9 Ltd, Cosina 55/1.2, DA*300/4, Contax Zeiss Distagon 28/2.8, Raynox 150/250, AFA x1.7, Metz 50 af1.

Nikon : D800, D600, Sigma 500/4.5, Sigma 120-300/2.8, Zeiss Distagon ZF2 - 21/2.8, Zeiss Distagon ZF2 - 35/2.0, Nikkor 85/1.8G, Sigma 50/1.4. Nikon x1.4 TC, Sigma x2.0 TC
Frogfish is offline   Reply With Quote
Old Jan 3, 2012, 4:15 AM   #4
Senior Member
 
Catbells's Avatar
 
Join Date: Nov 2004
Posts: 874
Default

Quote:
Originally Posted by mtngal View Post
Two possible solutions (which really are related) come to mind. I assume you are using auto WB - I find the WB on the K5 pretty good but it once in a while makes mistakes, and it can make slight changes as conditions change (noticed that today). One way to deal with that is to set the WB to daylight under bright conditions, or else set a custom white balance for the particular conditions. If WB is critical, like here, I'd set a custom white balance.
Thanks, I was considering setting the WB as a work around BUT given that the K5 doesn't always AE-L when the button is pressed and WB varies even when AE-L is functioning is backward step for the K5.

NONE of these happen with my K10 (or *istDS); having to use Manual Mode as a workaround for the K5's failure to AE-L and now having to set the WB for something that the K10 did automatically is a bit of a pain.

WB changes thus across the 4 frames: 6100/10, 5050/7, 5200/7 & 5500/8 which, given the narrow arc (20deg) for the composition & realatively constant lighting conditions, seems a tad excessive.

I'm considering returning the K5 as 'not fit for purpose'.
Attached Images
 
__________________
Pentax K10/K5, DA18-55mm, DA50-200mm & Tamrom 18-250mm

Last edited by Catbells; Jan 3, 2012 at 4:40 AM.
Catbells is offline   Reply With Quote
Old Jan 3, 2012, 4:18 AM   #5
Senior Member
 
Catbells's Avatar
 
Join Date: Nov 2004
Posts: 874
Default

Quote:
Originally Posted by Frogfish View Post
Shoot in RAW !
Using Lightroom kinda suggests that all shots were taken in RAW - hence the fact that I could compensate for the changes in WB.
Catbells is offline   Reply With Quote
Old Jan 3, 2012, 12:47 PM   #6
Senior Member
 
Frogfish's Avatar
 
Join Date: Feb 2006
Location: Shanghai, China
Posts: 2,774
Default

Quote:
Originally Posted by Catbells View Post
Using Lightroom kinda suggests that all shots were taken in RAW - hence the fact that I could compensate for the changes in WB.
No, it doesn't at all. Lots of people use LR without shooting in RAW and you didn't state whether you are shooting in Jpg or RAW or whether it was PEF or DNG. Even if shooting jpgs you can still change the temperature for different shots.

Obviously the light is going to vary from shot to shot so it doesn't, to me at least, suggest that the camera is necessarily at fault here.
Maybe the light changed slightly, maybe there is more/less/different light being emitted from somewhere in the shot which may affect the WB, there may be a dozen different reasons, none of which have anything to do with your settings.

You already know how to overcome it ... shoot in RAW and correct in LR3, you can easily set up a pre-set to handle it.
__________________
http://frogfish.smugmug.com
Pentax : 15 Ltd, 77 Ltd, 43/1.9 Ltd, Cosina 55/1.2, DA*300/4, Contax Zeiss Distagon 28/2.8, Raynox 150/250, AFA x1.7, Metz 50 af1.

Nikon : D800, D600, Sigma 500/4.5, Sigma 120-300/2.8, Zeiss Distagon ZF2 - 21/2.8, Zeiss Distagon ZF2 - 35/2.0, Nikkor 85/1.8G, Sigma 50/1.4. Nikon x1.4 TC, Sigma x2.0 TC
Frogfish is offline   Reply With Quote
Old Jan 3, 2012, 3:32 PM   #7
Senior Member
 
Join Date: Jan 2011
Location: Australia, New South Wales central coast
Posts: 2,907
Default

G'day CB

I do lots of panos too - great imagery

I would follow mtngal's suggestion and "at least try" doing a jpg comparison with WB=sunny

I have a Kx and it is a real bugga with AEL activities - it constantly fails to lock the settings.
I pre-sweep across the subject range, decide upon the primary metering point, manual focus it then meter it & press the AEL button, go the the LHS and start shooting images ... only to find that the exposure settings are altering with each move of the camera
It's got to the stage that I have abandoned AEL and manually set everything - like film camera days of 30years ago > except I have a modern camera & I expect it to behave like a modern camera

WB-wise, I never have autoWB - I always choose the WB to suit the lighting conditions

Regards, Phil
__________________
Has Fuji & Lumix superzoom cameras and loves their amazing capabilities
Spends 8-9 months each year travelling Australia
Recent images at http://www.flickr.com/photos/ozzie_traveller/sets/
Ozzie_Traveller is offline   Reply With Quote
Old Jan 4, 2012, 7:45 AM   #8
Senior Member
 
Catbells's Avatar
 
Join Date: Nov 2004
Posts: 874
Default Menu10 - WB Adjuastable Range

I think that I may have resolved some of the issues that I have with the K5 AE-L & White Balance Issues.

Changing from AWB to Daylight (or whatever) will not resolve the changing colour temperature during a sequence of consequative shots UNLESS the default settings in CUSTOM Menu 10 (White Balance Adjustment Range) is changed from:
1. Auto Adjustment - automatically adjusts white balance EVEN when light source is specified.
to
2. Fixed - does not automatically adjusts white balance EVEN when light source is specified.

I've created a User Mode which sets the mode to Manual with WB set to Daylight (as most panoramas are shot under these conditions), metering time to 30S and White Balance Adjustment Range set to FIXED.

I've created another User Mode which sets the mode to Av with WB set to Daylight (as most panoramas are shot under these conditions), metering time to 30S and White Balance Adjustment Range set to FIXED.

Interestingly, during tests I found that AE-L only became a problem when the WB was set to AWB - in Av (with WB set to Daylight), User Av & User Manual Mode, all consequative shots were AE locked & of the same colour temperature.

I still maintain that Pentax have not got AE-L correctly set - if it says that it should remain locked for as long as the AE-L is set and for twice the metering time, then it should do exactly that - nothing more, nothing less.

Quote:
Originally Posted by Ozzie_Traveller View Post
G'day CB

I do lots of panos too - great imagery. It's got to the stage that I have abandoned AEL and manually set everything

Regards, Phil
Thanks Phil - kinda nice to know that I'm not alone!
__________________
Pentax K10/K5, DA18-55mm, DA50-200mm & Tamrom 18-250mm

Last edited by Catbells; Jan 4, 2012 at 7:50 AM.
Catbells is offline   Reply With Quote
Old Jan 4, 2012, 3:14 PM   #9
Senior Member
 
Join Date: Jan 2011
Location: Australia, New South Wales central coast
Posts: 2,907
Default

G'day again CB

Yes - it's a pity to have to abandon a camera "feature" that's there supposedly to enhance our photo pleasure...
I have abandoned the Pentax completely because of this & other things that just do not work as I expect them to work and gone over to the Panasonic camera
The Pentax & its lenses is now in a box awaiting disposal

Regards, Phil
__________________
Has Fuji & Lumix superzoom cameras and loves their amazing capabilities
Spends 8-9 months each year travelling Australia
Recent images at http://www.flickr.com/photos/ozzie_traveller/sets/
Ozzie_Traveller is offline   Reply With Quote
Old Jan 4, 2012, 4:31 PM   #10
Senior Member
 
Join Date: Jan 2007
Location: Decatur, GA
Posts: 2,053
Default

Ozzie PM if you want to give me your Pentax lenses, I will put them to good use

dave
Photo 5 is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 7:59 PM.