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A Question about White Balance

Posted: Fri Nov 27, 2015 3:26 am
by astronomynut
In the initial opening of your fts data, Star Tools provides four choice for what type of data you have to present.

I use either a Canon 600D (unmodified), or a Canon 7D mkII (full spectrum modification). Both are Bayered, and both spit out "White Balanced" subs. I have my settings for WB as automatic. There are no choices to turn off WB.

So, just what button should I press to start my processing. The first two mention "Not WB". I have been using the second one. Should I be using the third button which means the program would try to reverse things before entering the processing stage?

My last thought is it possible that DSS takes care of the WB problem. If so, then the second button would be the appropriate starting point.

Sorry if this is all basic, and obvious to most of you, but before I started into AP, I had never had any kind of camera other than a film type back in the 1970's. These new DSLR's have so much in them, that it is very confusing. I've set things up as best I can, based on inputs from other photographers. Unfortunately, so functions are not very easy to understand, and it is worse because Canon does not provide an in depth users manual with the cameras. I guess they assume everyone knows how to use things. Caley

Re: A Question about White Balance

Posted: Sat Nov 28, 2015 2:50 am
by smokey688i
My understanding is for all linear, non-whitebalanced data coming out of a DSLR (full spectrum modded or not), use the second option since it was bayered (ie, came from a device with a 'Bayer' color filter array).

On the white balanced question, if you are stacking the raw files, and have the settings in DSS under "Raw/FITS DDP Settings..." in the "White Balance" section both unchecked (ie, "Use Auto White Balance" and "Use Camera White Balance" are both checked), then your stack output from DSS is not whitebalanced. This is regardless of what in-camera white balance you have selected. Only if you are stacking the .jpegs (which I would never do) are you unable to do anything about the in-camera applied white balance.

Another important option is under the Bayer Matrix Transformation section of the same settings menu...very long story short, the Bilinear Interpolation option is the best route to take. There are plenty of deep discussions on this topic scattered throughout the forums, but that's the conclusion I've come to after lots of reading and experimentation of my own...

I'm somewhat of a newbie here, so please chime in if I've misspoke!

-Chris

Re: A Question about White Balance

Posted: Wed Dec 02, 2015 4:59 am
by astronomynut
Chris, Sorry to be late replying. Had a very nice vacation, first in three years.

I guess I am doing things correctly. I am beginning to think that most of my problems in processing are not the processing, but the data. I need to concentrate on keeping things in focus. During the winter here in the high desert, we have quite a steady temperature drop off, that affects the optical tube, causing the focus to drift about every 20-30 minutes. Eventually I will upgrade my focuser and add an auto focus device.

The other problem I get is during the summer when the midnight temperatures can still be in the mid 90's. Makes for some very noisy pictures. But that might be partially solved after being told to start dithering. Since I've done that, the heat noise has lessened, though not totally gone away. Summers here are a real pain when it comes to trying to get good data.

And the last thing is I am now far enough into my imaging career that I finally realize that 20x120 seconds is not enough time on most DSO's. I am becoming more patient, and gathering hours worth of data, instead of being happy with an hour or less.

Seems that I am a bit slow to learn all of this, but at least I am learning, and in the process, becoming a happier photographer. Caley