Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-25-2013, 11:47 AM   #16
Site Supporter
tabl10s's Avatar

Join Date: Jun 2011
Location: Sacramento(formerly from B'Ham, England).
Posts: 1,399
My preemie had that look 11 years ago. Have the models do the shoot again and shoot JPEG in DNG and see what happens.

11-25-2013, 11:48 AM   #17
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,109
QuoteOriginally posted by TheBlindHog Quote
Yes, there was other lighting in the form of fluorescent.
Smoking gun...warm spectrum fluorescent by any chance?

Sorry about the misunderstanding in regard to RAW vs. in-camera JPEG. Like miguel, I took you to mean that this was imported as RAW. As I noted above, the WB for the flash light is spot on white. The snow flakes are not as bright, but also essentially neutral. The camera WB is appropriate for your flash but not for the ambient room light. Dim your room lights and see the results improve.


Steve
11-25-2013, 11:54 AM   #18
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by Miguel Quote
Was this also taken in the Pentax Portrait jpeg mode?

M
No, the K30 was set to Bright. Or4dinarily I pay no attention to JPEG settings because I am going to process the raw file and use the JPEG only for viewing in Windows browser.
11-25-2013, 11:56 AM   #19
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by stevebrot Quote
Smoking gun...warm spectrum fluorescent by any chance?

Sorry about the misunderstanding in regard to RAW vs. in-camera JPEG. Like miguel, I took you to mean that this was imported as RAW. As I noted above, the WB for the flash light is spot on white. The snow flakes are not as bright, but also essentially neutral. The camera WB is appropriate for your flash but not for the ambient room light. Dim your room lights and see the results improve.


Steve
I hear what you are saying but this has never happened before and I did not get the same result when I switched to the K30 camera body. Same fluorescent lighting, no color cast.

11-25-2013, 12:03 PM   #20
Veteran Member




Join Date: Mar 2007
Location: U.K.
Posts: 685
In the K-30, and presumably the K-3?, there's a menu option for what WB is (automatically) used when using flash. AWB, Unchanged and Flash. I keep mine set to Flash so that the normal WB settings can't interfere. On the other hand I suppose the K-3 may not have these options what with the fancy colour aware metering.
11-25-2013, 12:09 PM   #21
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by lister6520 Quote
I don't think auto white balance should be used with a non PTTL flash. AFAIK the K-3, unlike previous Pentax DSLRs evaluates the colour balance before the exposure, looking both at the naturally lit image as well as the one illuminated by the pre-flash. If you use the Auto WB with an external non P-TTL flash I think the AWB will be adjusted according to what the exposure sensor 'sees' in the scene lit by the available light, and that will normally be wrong. It will not 'know' that the scene would later be illuminated by a flash as there is no feedback from the flash to let the camera know that it is there.

I'm not quite sure why the WB is determined by the exposure sensor rather than off the recorded raw image. With P-TTL it is perfectly reasonable and a very good idea but for any other situation, be it natural light or illumination by a non P-TTL flash I would think that it is always better to use the actual recorded raw image to determine the white balance.

That said I am not 100% sure that the exposure sensor is being used for AWB even in available light but some not very scientific tests I conducted seem to support that view. In any case if things are the way I think they are it will probably be corrected quite soon in a firmware update.

It is worth noting, that the Nikon D800 specification describes the exposure sensor (which is the same 86K chip) as being used for white balance specifically for flash exposures.

I'm not familiar with the flashes mentioned, but I am supposing they are not P-TTL - if they are then you can disregard most of what I said above.
This seems very reasonable. I have experienced the issue on other shoots and I know I was PTTL with the AF540FGZ and Metz AF 50 Mecablitz in some but I don't recall whether the white balance problem manifested itself there or not. If your supposition is correct that means the camera can only be used with P-TTL metering and that excludes any and all strobes, so I hope you are incorrect.

When it comes to the K5 and K30 I almost always shoot manual white balance and almost always use 3rd party non-PTTL flashes and I have never had this issue, so I do believe something is different with this camera body and if it is setting the white balance based on ambient light instead of the flash that might explain it, for sure. If that is the case I hope they fix it or acknowledge that only Pentax P-TTL flashes can be used, in which case I will - regretfully - be leaving Pentax.
11-25-2013, 12:11 PM   #22
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by SteveB Quote
In the K-30, and presumably the K-3?, there's a menu option for what WB is (automatically) used when using flash. AWB, Unchanged and Flash. I keep mine set to Flash so that the normal WB settings can't interfere. On the other hand I suppose the K-3 may not have these options what with the fancy colour aware metering.
The K3 does have a flash WB setting. I am aware of the setting and seldom use it because I think it is too warm - at least on the K5 and K30. I have tried using it with the K3 but it does not alleviate this horrible color cast.
11-25-2013, 12:22 PM   #23
Veteran Member




Join Date: May 2012
Posts: 698
QuoteOriginally posted by TheBlindHog Quote
............ If your supposition is correct that means the camera can only be used with P-TTL metering and that excludes any and all strobes, so I hope you are incorrect. .............
It's not nearly that drastic actually - it just means that one had better not use AWB for non P-TTL flash until that is fixed (that is if it is actually broken). I think it is any case never a good idea to use AWB for flash photography since with flash the light source is very accurately known so WB should be set manually to the colour temperature of the flash rather than leaving it to auto,

By default the camera actually does that itself (unless you override the setting) but with a non P-TTL flash it won't even know that a flash is being used so cannot switch to the flash WB preset.

What I say about avoiding AWB for flash photography is also valid for any camera, not just if it has the problem I think there is with K-3, the AWB will in any case not be as good as the flash preset, especially if there are significant areas where lights other than the flash are dominant.

To summarise - for flash photography never use AWB, in case of the K-3 there is even more reason to avoid it except in specific cases.

One of those specific cases is indeed when using a K-3 with a P-TTL flash, or for that matter any camera that has RGB flash metering of which there are very few apart from the K-3.

11-25-2013, 01:09 PM   #24
dms
Site Supporter




Join Date: Aug 2011
Location: New York, NY
Photos: Gallery
Posts: 1,614
As regards the "camera getting it right," as stated above, set the WB for the flash temperature (or setting)--assuming (hoping) the other light intensity is a lot less. But if the other intensity is not a lot less--then there is no way for the camera to properly handle it--you need to alter one of the light sources so it has the same energy vs wavelength (same effective black body temperature) as the other.

Fluorescent does not have a black body spectrum but it may be close enough to use a temperature as I suggested. (A famous photographer [?] said something like "God made light, but not Fluorescent, which are the work of the devil!)

My caution (for future?) is no camera can properly adjust for mixed lighting--when they are similar intensity
11-25-2013, 01:42 PM   #25
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by lister6520 Quote
It's not nearly that drastic actually - it just means that one had better not use AWB for non P-TTL flash until that is fixed (that is if it is actually broken). I think it is any case never a good idea to use AWB for flash photography since with flash the light source is very accurately known so WB should be set manually to the colour temperature of the flash rather than leaving it to auto,

By default the camera actually does that itself (unless you override the setting) but with a non P-TTL flash it won't even know that a flash is being used so cannot switch to the flash WB preset.

What I say about avoiding AWB for flash photography is also valid for any camera, not just if it has the problem I think there is with K-3, the AWB will in any case not be as good as the flash preset, especially if there are significant areas where lights other than the flash are dominant.

To summarise - for flash photography never use AWB, in case of the K-3 there is even more reason to avoid it except in specific cases.

One of those specific cases is indeed when using a K-3 with a P-TTL flash, or for that matter any camera that has RGB flash metering of which there are very few apart from the K-3.
I switched to a K30 immediately after taking this shot and the white balance was set to auto and the shot was "normal". This problem is definitely unique to this camera body and/or the K3 and if it is not correctable I will indeed feel obliged to switch to a new camera maker. I have been shooting Pentax since 2007 and have never encountered this issue on any previous body - K100, K20D, K7, K5, K30.
11-25-2013, 01:44 PM   #26
Site Supporter




Join Date: Oct 2011
Photos: Gallery
Posts: 65
Original Poster
QuoteOriginally posted by dms Quote
As regards the "camera getting it right," as stated above, set the WB for the flash temperature (or setting)--assuming (hoping) the other light intensity is a lot less. But if the other intensity is not a lot less--then there is no way for the camera to properly handle it--you need to alter one of the light sources so it has the same energy vs wavelength (same effective black body temperature) as the other.

Fluorescent does not have a black body spectrum but it may be close enough to use a temperature as I suggested. (A famous photographer [?] said something like "God made light, but not Fluorescent, which are the work of the devil!)

My caution (for future?) is no camera can properly adjust for mixed lighting--when they are similar intensity
I switched to a K30 camera body immediately after making this image and the K30 handled the shot perfectly. I am not new to portable studio set-ups, I do it fairly regularly and in all sorts of lighting and have never experienced anything remotely like this.
11-25-2013, 01:53 PM   #27
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,109
QuoteOriginally posted by TheBlindHog Quote
if it is not correctable I will indeed feel obliged to switch to a new camera maker.
At the risk of being blunt, the answer is to control the light. That is why we use flash or other studio lighting. Once you have control of the light, managing the camera and PP is easy.

Back in the days of film, your results would not have been any better. That you had acceptable results with your earlier Pentax cameras appears to be accidental. I shoot with a K10D and frequently encounter problems with "mixed-light" situations with the results being similar to your example photo. This is hardly the camera's fault. After all...how would you expect the camera to properly anticipate and correct for your setup? How is the camera supposed to "know" that your key light (the flash) is too weak and overpowered by the already strange spectral profile of a modern fluorescent tube.


Steve

BTW...Did you try turning off the room lights? Alternative, turn off the flash?

Last edited by stevebrot; 11-25-2013 at 02:04 PM.
11-25-2013, 02:02 PM   #28
Pentaxian
dosdan's Avatar

Join Date: Dec 2007
Location: Brisbane, Australia
Photos: Gallery | Albums
Posts: 1,697
An experiment. Have you tried Multi AWB, Menu C2, Item 11 (WB when using flash), p.55 of the manual? You would probably need to develop the resulting PEF in the Pentax DCU program as other programs may not interpret the MAWB portion of the raw metadata correctly yet.

Dan.
11-25-2013, 02:16 PM   #29
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,756
QuoteOriginally posted by TheBlindHog Quote
I have not tried it on another setting
Shoot a JPEG with the K-3 'Image Tone' set to 'Natural' (after resetting all your Custom settings to the defaults).

And how does the internal flash shoot the scene?

Also shoot a DNG and feed that into your normal workflow.
11-25-2013, 02:21 PM   #30
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,109
QuoteOriginally posted by TheBlindHog Quote
the K30 handled the shot perfectly
Well, there is your answer. Send the K-3 back and keep the K-30.


Steve
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
auto, balance, balance issue, cast, color, dslr, flash, issue, issue with flash, k-3, k3, pentax, pentax k-3, photography, problem, results, white balance
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Weird white balance issue on my K-5 with flash Codazzle Pentax K-5 3 01-02-2013 04:04 PM
K-r white balance with flash msatlas Pentax K-r 5 08-15-2012 12:37 AM
flash white balance problem adwb Flashes, Lighting, and Studio 3 03-13-2012 08:47 AM
K5 flash white balance adwb Flashes, Lighting, and Studio 5 02-17-2012 04:07 PM
White Balance with Ring Flash john mood Pentax DSLR Discussion 13 08-16-2010 07:16 AM



All times are GMT -7. The time now is 05:11 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top