Aluma 8300 gives occasional blank image

I've recently put a new Aluma 8300 into service. Several times throughout the night the Aluma delivers a blank image, by which I mean that all pixel values are zero. This creates a number of problems for autofocusing (the software assumes a longer exposure is needed) and mapping (the last retry is blank and fails). Is this a known problem and is it likely to be caused by the hardware or the software? I am controlling the camera with MaxIm DL Pro 6.20, and using the Diffraction Limited MaxIm DL's camera choice in TheSkyX.

 

Hi Greg,

I'm a hardware engineer working on the Aluma cameras. We extensively test all our cameras and I have never experienced this issue. It obviously should not happen. Could you please give me more details so I can thoroughly investigate it?

1. Can you tell me your camera's firmware revision? It should be in Camera Settings in MaxIm DL.

2. Did you have the cooler on? What was the sensor temperature and approximate cooler power?
3. Were you taking light or dark frames? What was the exposure time?
4. Could you send me the FITS header of one of those blank images? (it should contain the answers to the two questions above)​

Those details may help me pin point the problem. Since it is a highly unusual issue, it will require some investigation.

 

Will do!

 

OK, here are the details:
1) Camera firmware is 16.
2) Cooler was set for -25C and was around 61% power.
3) I was taking light frames.
4) See attached.

More comments: The camera was connected to MaxIm DL and was being accessed through TheSkyX software as "Diffraction Limited MaxIm DL Camera". I was using the focus technique in TheSkyX and every time a blank image came up the software failed to detect the star being focused and so increased the exposure time.

 

Hi Colin and Kris W,
Tonight I tested this out and found that the problem remained when binning was set to 1 x 1. To search for the problem elsewhere, I disconnected the camera from the selection of "Diffraction Limited MaxIm DL Camera" in TheSkyX Pro, and directly accessed the camera using MaxIm DL Pro version 6.20. I did not experience another blank image. I used the Focus routine in MaxIm DL Pro without the blank images re-occurring and was able to successfully focus. This suggested to me that the problem related to the interaction of MaxIm DL Pro with TheSky X Pro, and, at least for the time being, could be avoided by only using MaxIm DL Pro. However, I immediately ran into another problem. I have the Aluma Self-Guiding Filter Wheel and so setup the Camera in MaxIm DL Pro with "Dual Chip Mode" selected. When I go to the Guide tab in MaxIm DL and take an exposure I get either an image with lots of thin vertical white lines with an error message saying:

"Camera 2 Information
Error in plugin callback (519) - Could not set FITS key 'EGAIN'
Error in guide camera plugin callback 519
Camera Idle
No cooler control"

or a small white image with an error message saying:

"Camera 2 information
Could not acquire target
Could not find target star in ...
Guide star not found
Camera idle

Since descriptions might be inadequate I have uploaded two screen capture files.

One extra comment. While trying to get MaxIm DL to work with the Aluma camera, I found that MaxIm DL would hang immediately after the first button in the camera control window was pressed. This was fixed by opening Setup|Options|Advanced and checking both options for a separate thread for both camera and filter wheel. I nearly went crazy until I discovered this. It might be worth putting it in the initial instructions in the manual.

 

OK, here (attached) is the FIT file of the Guider Expose. The clouds have come over and this is taken inside the domed observatory, but it looks exactly the same. I'll have to work out how I took the one which is all white.

 

Hi Greg,

Sorry for the late response but for some reason I didn't get notifications about your recent posts.
I got involved in case it was a hardware issue with the camera but it seems it's software so I have notified our software engineer to look into it.

The guider image with vertical lines looks like a saturated image. Maybe there is a light leak? Could you try to cover it completely and take another picture with the guider? Did you take any bias frames with the guider? Do they look okay or are they all saturated as well?

 

Hello Adam, (and Kris and Colin),

Nearly there I think. After some hours of swapping things in and out, I discovered that the source of the autoguider image with vertical lines was the HDMI cable between the camera and the guiding filter wheel. After I replaced it, the vertical lines disappeared. However, the guider frame remains problematic, in so far as it is an image with all values at zero. I will upload it.

In setting up the Aluma camera and guiding filter wheel with the MaxIm DL Pro software, I noted that one is not supposed to allocate guiding to a second camera, but check "dual chip mode" and use only "Camera 1" on the setup tab. However, one had to choose between Camera 1 and Camera 2 on the Guide tab for a guiding image. The size of an image after selecting Camera 1 seemed to indicate that the software was accessing the main imaging chip, therefore, despite the advice about setup, I chose Camera 2 on the Guide tab. This resulted in the blank guide image.

Adam, if there is not a way forward given this information, I am willing to let you use Team Viewer to access my setup. However, if there is a way forward without it we might get around a large time difference. I am assuming you are in the US Eastern time zonw (I know you are in Canada). I am in the Eastern Australian time zone, at 10 hours ahead of UTC.

 

Hi Colin,

Yes, I powered off the camera before changing the HDMI cable. It was hard to miss all the multi-coloured stickers warning about not plugging in or unplugging cables into the I2C/FW/AO sockets without powering down. I thought I'd make sure by not plugging in or unplugging any cable without powering down. I only swapped the HDMI cable for the first time a few hours ago and my problems developed well before then.

Tell Adam I can work within Canada business hours. I'm retired now and can stay up till dawn if necessary.

 

Adam, I think I've got this right. See attached.

 

Adam,

I just tried a third HDMI cable and the vertical lines returned to the guider image. When the second HDMI cable showed no vertical lines, but just a blank frame, I thought it had solved the problem; but the cable number 2 must have been faulty one. So if two out of three HDMI cables show a frame with vertical lines, that frame remains as the problem.

 

Mo

OK. Here are two images taken with the guider after making the changes you suggested.

I'm about to turn in for the night (3:42 am), business tomorrow. Keep the instructions coming and I'll resume when I'm free.