I have been using this filter wheel now for several years and no issues, it seemed to act funny the other night, yet MaxIm gave no indication that there was anything wrong when the filter wheel moved. If there is any issue during movement of the filter wheel, say not getting to correct position, would this be detected by MaxIm and an error message given?
What camera are you using it with, and what does "act funny" mean? MaxIm will usually say "Waiting on filter wheel" if there is a failure.
Using the SBIG 16803. I had started an LRGB image sequence on a relatively bright galaxy. I was monitoring from in my house because it was a cold night (~33 F). When the L image came up (30 minute exposure) there was barely visible anything on the image. I thought that perhaps because of the cold that the filter wheel got stuck between filters so almost nothing was getting through. But the software didn't indicate any issues. Since that night I wondered if perhaps a cloud covering had gone over also blocking things. I thought I would just ask the question if the filter didn't get into position, would the software indicate an error, sounds like it would. Have not had a clear night since then to re-evaluate everything.
If it was stuck between filters, you'd have two regions with stars and an angled dark section between them, as there is very little space between the filters. If it is the shutter, you'd have either uneven exposure areas, or the image would be blocked parallel to the shutter edge. If you have it happen again, upload a FITS image showing the problem and we'll take a look.
Colin I continue to have issues with some of the filters where there is essentially no image using some filters, as if the shutter is closing early on in the image. How do I post a series of images on the forum to be looked at? I did a search on posting but could not find anything on it.
Here is a sequence run in MaxIm (6.30), 16803 camera. 2minute each starting at C filter through sequencially to L, R, G, B of M109. This is what I am seeing and I know that C and L filters should be nearly the same, faded image also always appears in G.
Hi Dale, The vignetting is oddly L-shaped in C,B,R images. Not visible in G, Luminance filters almost look like you are not getting any light, and are seeing Residual Image effects. This would imply the shutter did not open. Usually, Clear and Luminance ADU counts are very similar, not quite identical (L = UV/IR blocked). You're going to need to look down the nose of the camera. On the scope, you might be able to point a cellphone toward the detector through the hole in the primary (eg hold up near secondary, in front of it) and take a few shots or video. Off the scope is easier. The L shape could be the FW7-STX is not positioning the filter correctly. Possible cause is the opto-sensor in the filter wheel has come a bit loose and it has swung out of position. I realize it's a pain, however I think you're going to have to have a look. Put the camera on the workbench, connect it, and do a few 10sec shots on each filter while looking down the nose of the camera to see if the FW7 is putting the filter squarely in front of the CCD, and if the shutter is fully opening/closing and not sticking. If you determine the FW is not positioning correctly, then inspection of the carousel, drive belt, and opto-sensor will be necessary, which means disassembly.
Thanks Colin, I figured, plan to take off camera and play at bench tomorrow. Funny though, it seems fine for short exposures. I fact when I started my sequence of LRGB photos. I first did short exposures 5-10 seconds at L setting to make sure everything seemed fine. Yet you see the results with the actual seqence I sent you. I will keep you posted. At least withe everything on workbench I can monitor bothe shutter and filters at same time. I would have thought that some error message would have shown itself. Dale
Forgive me, this is a dumb one - I did it myself - Any chance the filter order is wrong? I once blew away the list of filters and went with the default (an upgrade and I was not paying attention). This had the unfortunate effect of making the filter "name" mismatch it's actual position. e.g. I thought I had "Green" but the carousel slot actually was Sulphur II, which won't pick up much data on some targets. If there was a "hard fault", we'd likely see a shutter error or filter wheel error. That's why I don't have more specific guidance. I'm not convinced there is a hardware failure at this point, as some of your earliest images had slightly odd vignetting. You could send over the MaxIm logs and I could have a look in case there is something obscure. In MaxIm, View... Log Window. Right Click. Open Log Folder. Then you can zip them up and attach with [Upload a File].
I removed the camera-FW7-autoguider from the telescope and set it up on table next to telescope. I then put the system through the same sequences I had trouble with before. Of course predictably the system performed flawlessly every routine I put it through. I was able to follow the filter changes and shutter function perfectly well and no issues came up. All cables were in place and I even used the same temperature on the chip. All filters are in the correct position as they have been for 4-5 years now. Now I recall reading a thread last week concerning an issue exactly like mine. Unfortunately I have not been able to find that thread again and I tried hard to locate it. I recall the last post was around October of 2022. I did not see if that thread was ever resolved or not but I do not think it was. I do recall that suggestions were made by you I believe to check out all the cables, how come connections can develop corrosion. I am not saying that was the case for me, but in unplugging and replugging in all the cables might have had an effect? I guess the only way I will know is to reattach equipment to the scope and try it again during a clear night. Any other ideas you might suggest will be welcome. One other note, I went back to my imaging nights from late last year and everything was working perfectly as expected into October 2022. I then basically don't get out until spring again because of the foul nature of our weather here in southwestern Michigan. My first night out in April 2023 the issue we are talking about showed up, repeated sessions later also had the issue so it's a function of the start of the year after winter hibernation.
I found that thread finally, it was called: SBIG STX RANDOM BAD IMAGE It is closed out now but it is not clear if the issue was ever resolved. The last post was by Colin, closing it out on October 2022
Dale, the thread is closed due to customer-specific private matters. There are multiple customers and issues there, and I don't think it is related.
