Flat -problem with Canon Ra + ASIair Plus

Gernot

Hello from Austria!

I have connected my Canon EOS Ra to an ASIair Plus and would like to create flat frames. Since the "auto" setting doesn't work with the flat frames on the DSLMs, I tried a manual exposure time. I use a homogeneously lit flatfield box as a light source and the result is that I always get flats of different brightness, even though the exposure time is constant.

Can you even create calibration files with the combination of ASIair and DSLM? Does anyone know this problem and have any suggestions for a solution?

CS Gernot

Tech@ZWO

Gernot 'Auto' setting should works.
Could you check the parameter of the images? such as ISO, exposure time and so on
And how many is the ADU value difference between these flat frames?

b5193W4C

Gernot Hi .....Ermes from Italy. I currently have the same problem with both reflex and mirrorless cameras. Did you solve the problem? If so, how did you do it? Hi and thanks anyway.

Gernot

Tech@ZWO

Thanks for the quick reply!

Today I did a test with the "auto - flat" function. The Canon Ra was connected to the ASIair using a USB3 cable and I used the flatbox again as the light source.

It takes about 20 seconds to determine the optimal exposure time (the camera triggers very often). During the autorun (30 images) the avg values fluctuate between 22000 and 34000...

I think that can't be right!?

CS Gernot

Tech@ZWO

Gernot What is the value of ISO?
Is it possible the light source of your flatfield box changed during imaging?

Gernot

Tech@ZWO

The flats were shot at ISO 800 (like the lights) and the flatfield box was powered via the ASIair.