The are Problems with the Atik 383L+ ?

[Miguel Rivas]

This image is a 15x900 seg.  H-alfa  process with MaximDL v5.18.
It appears like a "rain" background

[Kaidan]

It would be better to post a single frame FIT with only histogram strech.

[Miguel Rivas]

This is a single frame

[Konihlav]

you need to calibrate your raw FITs images prior stacking them (median combining). I'd recommend to calibrate for dark current with master dark frame composed of many single darks. Do use median combine (I do not know why there's unsuitable average settings in MaxIm DL as default). Also, when combining, click checkbox - ignore black pixels (happens from hotpixels in flat fields if FF are also uncalibrated).

[Miguel Rivas]

I calibrate the raw Fits with darks, bias and flats before the stacking.....

[timwebster]

Miguel,
I have experienced exactly the same effect when imaging horsehead in HAlpha with 383L+ - no idea why it happens.
Tim

[Konihlav]

Miguel, are you sure? did you test if calibration works on one single frame (Undo/Redo) ? The image you posted seems everything but calibrated. How many calibration frames do you use? (I usually stack 30-50-100 frames for a master calibration frame). Did you turn cooling on ?

[Miguel Rivas]

There are two theories:
a) Problems of calibration
b) Low voltage of  Power Tank
Yes, I turn cooling on ( -20ºC)

[amenophis]

Hi,

did you solve your problem?

I've got the same and nobody does know about it. I sent Vince a Darkframe, hope he can help me.

Regards,

Thomas

[Lenny]

I looked at your image in the original post. My question is when did you take the dark frames? If you didn't take them while the camera was at the same setting...that is right before or right after doing the luminance series you'll get this sort of effect. You cant's take reduction frames the next day after turning the camera off.