Gina

Yes, very good for a DSLR.

Results of Flats experiments so far :- 4 layers of T-shirt over dew shield, cloudy sky - dreadful, very uneven 4 layers of T-shirt over bare lens, cloudy sky - better but showing fabric weave 4 layers of T-shirt over lens with white paper disc, cloudy sky - much better but too much light loss White paper disc over lens, blue sky - uneven illumination Conclusion :- sky is too variable and unreliable.

Thought I'd try just the paper diffuser with the rig pointing at a clear blue sky with a shield to keep direct sunshine off. The field doesn't look even - I would expect to see a circular pattern, brightest in the middle and dropping off to the edges. This screenshot shows a strange shape (as well as a typo in the filename). The sky is not a flat field. The amount of Ha reaching the sensor is small - the exposure went to over a second! The more I experiment the more a light box seems that answer.

I've ordered this 5mm Perspex Opal for LED Light Box Gloss Acrylic Sheet with the idea of making a light box. Due to arrive tomorrow. Seems to me that it would be better than relying on the sky.

Looking good

I had a "real flat panel" several years ago but stopped using it. I forget why now. I may make up a light-box using filament bulb(s) and an opal sheet (or two). KStars has provision for remote controlled use of a light-box or flat panel. FLO don't seem to have any Artesy flat panels and they're very expensive direct from Artesky.

I've used twilight Flats in the past as well as other times of day and didn't see T-shirt weave appearing but I guess the previous Windows software didn't apply as much stretch to the images. Using paper as well as the T-shirt solved the weave problem but cut the light transmittance right down and I was finding it needing 30s exposure by early evening with Gain at 0. Fortunately I don't have an ASA mount - mine is SW EQ8 (and also an NEQ6) and when I make my own mount later I shall make it compatible. This means that I can use a standard INDI driver but if I find any problem making my own mount compatible I could probably edit the INDI driver to suit. One advantage of open-source software. Talking of battles with KStars, this is nothing compared with all the trouble I had getting Windows software all working together a few years ago. And then I was younger, with a younger brain. KStars seems much better.

Sorry posted in error.

Closed up for the night. Looks more likely to rain than clear.

It's stopped saving again!

I think fewer layers of fabric may be better.

Disc of paper placed on top of lens the 4 layers of T shirt on top. Exposure increased to 2.5s. Light source is cloudy sky.

CurvesTransformation.

OK. I guess the way to see which is better is to try both processing in PI. OTOH I'm wondering if an LCD screen would be better. Though don't know if the wavelengths produced would work with the NB 3nm filters. Guess a filament lamp lamp with wide spectrum would be a better source as an alternative to daylight.

Image file in PI.

Tried without the dew shield - straight on top of the lens. It's different!

I'm not sure the Flats setup I'm using is working well for the widefield rig ie. 4 layers of white T shirt stretched over the dew shield.

Better - all 60 subs captured, downloaded and saved.

Put a 10s delay in the capture form and doing another run of 3x20 subs. Think I've solved the KStars taking over problem. Unticked "Focus on receiving an image" in the FITS settings.

I'm saving my images to the system SSD on my Linux Mint desktop. The exposures are now around 0.5s. I don't have the Pro ASI1600MM. I can try putting a delay in. Ha Flats went OK, OIII same but SII stopped saving halfway through. Tried with just 20 subs each this time. Adding a delay might stop the saving failure. I still have KStars taking control of the computer when it has downloaded a sub, interrupting what I'm doing. It didn't used to do this - I could leave KStars capturing, downloading and saving images in the background while I did other things. Any ideas?

File info "/home/gina/0-Astro/Flat/H_Alpha/28mm_2x_Flat_H_Alpha_0.461_secs_2019-07-07T17-40-58_010.fits". That is right. But will see when there are other files around.

Might haave finger trouble with knitting!

I'll save to a brand new folder on my system drive. Just to avoid any confusion (hopefully!!!).

One thing I can try that sometimes works when computers and software is playing up. Shut everything down, restart and try again...