Welcome to the forum!

As an adjunct to the Tangents blog, the intention with this forum is to answer any questions, and allow a diverse discussion of topics related photography. With that, see it as an open invitation to just climb in and start threads and to respond to any threads.

TTL and color temperature

Maybe a stupid question, but when flashing TTL , does it also change the color temperature (white balance)?

For instance:

When I take a picture with my flash on manual it seems that the picture is colder then when I make the same picture using TTL (which has a warmer color and more pleasing)

Comments

  • TrevTrev Moderator
    edited July 2016
    Idoetje,

    Nope, not a silly question at all, and yes, in fact you are right with WB being affected with TTL and Manual Flash.

    Now, to dig a bit further as to why, generally speaking the lower the flash power the more blue is injected into the image, because the nature of a speedlight's WB in manual and TTL do vary even though you may have a 'correct' exposure on both, and probably in manual you are setting a bit less power whereas the TTL may pump that bit extra out.

    I don't have a full explanation as to precise measurements but I do know that TTL vs Manual can cause WB shifts when you think exposure should be the same and I have experienced it first hand also, so you are not dreaming at all in that regard.

    Now I assume you are setting your WB to Auto WB? Because the camera's hot shoe it 'talking' to the flash and it will adjust accordingly and if less power is needed, then the more blue it will seem.

    I do know that if you set your camera's WB to Flash WB the temperature will be a constant and if using a speedlight on camera and I am in normal light and the flash will primarily be the dominant light source, I will set Flash WB and that will give me a constant, but that's rare since I use mainly off camera flash, manual and set a dedicated Kelvin WB to suit the lighting conditions I am shooting under.

    The other thing on the flipside is, I am not that concerned anyway, since I shoot in RAW and no matter how accurate you think you are in camera, WB nearly always gets a tweak from me anyway, so in reality it's a moot point, but that's the best explanation that I know of.


    Maybe have a little Google and see what you can find.

    Trev.

    Edit: Just found this article: http://www.scantips.com/lights/flashwb/

  • Thank you for your explanation Trev.

    I am always working  in Raw and most of the times using auto white balance.

    Glad to find out that I was right ;)

    I will check out the article... thnx
  • rs_eosrs_eos Member
    edited July 2016
    If you're using RAW, the white balance setting ultimately doesn't matter.  The only thing captured in the RAW is metadata about which WB setting you've used and will thus automatically select that value in LR, ACR, or presumably any RAW converter.

    Any subtle shifts in WB are easily corrected in the RAW converter.  To help aid in that, you can always shoot a "color checker" (e.g. Datacolor or X-rite brand).

    Side note on AWB... Personally, I stay away from it.  JPEGs you capture (e.g. shooting RAW + JPEG) will have the WB baked in.  I tend to either use a custom Kelvin value or any of the fixed presets.  Additionally, the image displayed on the back of the camera will be a JPEG, so having the best representation and deterministric value of white balance is something I strive for.
  • The last line is very good advice. Never thought about that.   Thanks for the tip
  • Neil vNNeil vN Administrator
    I don't think the color temperature will vary between TTL / manual flash, for the same flash power. So it isn't a TTL thing. 

    And yes, color balance may shift a bit.  I've noticed it in high-speed flash sync as well. 
  • Neil,

    According to the specs TTL does affect the WB. It says : Auto WB with color temperature signal to camera
  • Neil vNNeil vN Administrator
    TTL doesn't relate to Auto WB. 
Sign In or Register to comment.