Problem with first images from Canon 750D when using asiair plus

paul_zwo

Have recently purchased an asiair plus which I'm using with a HEQ5 Pro mount, ASI290 mini guide camera and Canon 750D. First run went well with PA and guiding but I subsequently found that my images have horizontal pairs of lines running across them at wider vertical intervals (pair of lines, a larger gap then another pair of lines repeated from top to bottom). This doesn't happen when using the camera independently of the asiair. I've tried different cables and different speed usb ports with no change. (camera is usb 2 capable).
Any ideas??

Tech@ZWO

paul_zwo Could you share some images with us?
You can share them via google drive if they are too large, thanks.

paul_zwo

Hi, I've tried to attach example lights and flats FITS files but they're to large. You'll need to send me some instructions on how to get them to you via google drive.
In the interim, I've have attached screen capture images so that you can at least see what I'm getting. The issue is most apparent in the flat files but is also present in the lights. After my first stacking outcome using all data, I tried again without the flats, which made me realise the 'interference' lines were also in the lights. I note that when a was recording frames to both the ASIAIR and the 750D, the CR2 files on the 750D also had the same problem. This does/did not happen when I use the camera independently of the ASIAIR

Tech@ZWO

paul_zwo If the raw images in the DSLR also have the same problem, the problem may be with your DSLR, because these images are taken by 750D, ASIAIR just to send the shoot command.

You can use 750D to take an image with the same exposure time, and compare it and the image taken via ASIAIR

paul_zwo

I understand your point but - if I collect images using only the 750D, I don't have this problem. If I use the 750D with the ASIAIR, then I get the results described. It seems apparent that whatever is going on is related to the interaction between the ASIAIR and the 750D. The fact that the problem is found on the image data on both the ASIAIR and the 750D must be a clue of some type. A communication problem?
I believe I've already done the test you suggest but I'll do some further flats images with and without the ASIAIR involved and report back on what happens.

paul_zwo

I've re-run some individual flats images recording to both the ASIAIR and the 750D, the ASIAIR only and the 750D standalone. I can see the interference lines in the ASIAIR (FITS) images for all cases but some some reason the contrast is not as strong as in the original case. I can't actually see the interference lines in any of the individual 750D (CR2) files. It seems that they are only apparent after stacking of the CR2 files and only for images collected when the 750D is connected to the ASIAIR.
The only change I've made between the original data and collecting these test images is I've changed the USB2 to mini cable to a much short, better shielded version.
Any other ideas?

ryba

Hi,
Has your problem been solved? I have exactly the same thing. Please help if you managed to solve this problem.