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Autodarks, preflash and SIPS

CCD Help Needed
KODAK 8300 sensor •2 replies•28 views
SicIturAdAstra avatar
SicIturAdAstra avatar
Hi everyone,
Just got my newly acquired (but not new!) G2-8300, I have setup everything and it seems to work well. I haven't test on the sky yet because of, well, weather of course…
First CCD for me (I was using, and still use cmos), so "autodark" and "preflash" are new to me.
The previous owner told me he was doing autodark (with MaximDL). I'm using NINA.
So, I was wondering:
-Will "standard" darks will work as well or is it preferable (i.e. are you doing it) to do autodark?
-As NINA hasn't any option it seems for preflash, will it be an issue? The ASCOM properties have a preflash option but it looks like I can't tweak it.
-Are you using SIPS? Is it mandatory? Or in other words, do I need a software with "more control" like SIPS and SGP?

Can't wait for those damn clouds to go away…

Thank you!
Engaging
Ben Koltenbah avatar
Ben Koltenbah avatar
Congratulations on your "new" camera!

For many years I've been using a QSI683, which is also a KAF-8300.  To my knowledge, RBI is not considered an issue with this sensor, nor have I ever noticed it.  As a result, preflash is not typically needed with it.  This is not the case with other KAF sensors.  For example, I also have a KAF-16200 sensor, and my imaging benefits from preflash under certain circumstances.  Your experience may differ, but my statement is based on what I understand to be general lore about the KAF-8300.

I'm not clear what you mean by "autodark".  Is this some kind of on-camera procedure that applies dark subtraction to the image prior to downloading to the computer?  Or, is there an autodark procedure in your frame capture software?  If either of those two is the case, I would recommend that you not apply this autodark as it may mess you up unless you really know what it is doing.

Instead, I recommend you capture raw, unaltered frames and create your own master dark frames and master flat frames and do your calibrations yourself.  I prefer to capture and store raw image frames that have not received any special automatic treatment so that I can experiment with my own calibration as needed.

I'm not sure what you are asking about SIPS.  I use SGP, which captures my raw frames in FITS format.  Whatever software you decide to use, I recommend that you capture in FITS format rather than to use software that may capture and process directly to JPG or some other form.  Again, I recommend you preserve the ability to calibrate and process on your own!

Take care and good luck!

Best Regards,
Ben
Helpful
SicIturAdAstra avatar
SicIturAdAstra avatar
Hi
Sorry for the late answer, lot of work!
Thank you for those details. I will see about the preflash if there is an effect.
Well, as I understand, autodarks are taken directly after the exposure and the sub is, in this way, already calibrated. I don't really like this if it's the case, as you said, I prefer to get unalterated frames and to have total control on the process and result.

By the way, are darkflats a thing with CCDs? Because it seems to work better than bias with newer cmos. I get better results with them with my ASI533.

Thank you

Thibault