Over the last several months I've been getting a blown out image. It doesn't matter if I'm taking flats, darks or lights. Its occurs now and then, and I'm approximating maybe 1 in 50 frames. Is this a shutter issue and it needs servicing? If so, Is this camera a good candidate for the transplant upgrade service? Here's an example of a blown out image. (I shared this link through my dropbox and pasted the URL into the image link but, but I don't see the image, so I tried uploading the image.) https://www.dropbox.com/s/5it4cg2z5pknwb5/IC 434 blowout.PNG?dl=0 thanks Jim
Hi Jim, we can't tell much from a PNG. Use [Upload a File] to attach a file or image. That works better than the image button on the toolbar. Can you send us a set of uncalibrated FITS images, binning 1x1? Dark, Bias, light, and flat if possible. What's your optical train setup? e.g. scope (4000mm f6.5), any focal reducers/barlows, extension tubes, AO, off axis guider, filter wheel, filter, etc. Without the FITS, am curious - do you have a nearby light source / light leak - it could be an internal reflection off something in the optical path. Other test you can do is put the camera on the workbench (kitchen table) and shoot a series of second exposures, eg like 10 secs to see if the shutter operates correctly. If it needs servicing, it's usually more economical to send it for a quick trip to @Bill for a little TLC. Sometimes the shutter motors get a bit gummed up over time. Let us know the camera serial number. A tranplant to an Aluma 8300 might make sense, but I think it's something simpler.
I use a 14" Planewave Corrected Dall Kirkham f7.2. The light goes straight through to the focus wheel (FW-8) and into the STF-8300, so FL=2563mm I only shoot using 2x2 binning. I uploaded two 180 sec Red images. One with the blowout and one without. Also a single dark. I didn't finish taking flats for this image so now it may be too late. Typically I just delete these blown out images. For my Jan 6 session I too over 50 images and just two were blown out. Model: STF 8300M Serial: 83F010733 Thanks Colin.
Hi Jim, I think it should go in to @Bill for service. I think the shutter *is* acting up a bit - may need a new motor - I shouldnt speculate. I'll suggest he reach out to you. Also your darks are just a touch warm, but then again, I see the CCD was cooled just to -10, and if it's around 10C at night, you should be able to get that down further (maybe -20C or so?). Pro Tip: Your SITELONG has the wrong sign if you are in California. West of Greenwich is negative. Check MaxIm... File... Settings... Site and Optics.
I use The Sky X and checked my longitude and it shows 117° 09' 39.00" W. I will ask about this in TSX forum. I left the Temperature at what was recommended in the TSX camera addon and the outside temp was around 65F ~ 18C. Its been a few years since I dried out the desiccant
Hmmmm.... I don't use TSX for imaging, ask over on the Bisque forum. Because OBSGEO-L is correct. OBSGEO-L = -117.160833333333 / Longitude of the observation in degrees. Depending on the vintage and model of STF can achieve -30 delta T pretty easily. The STF-8300EN could hit about -40 delta T. You might want to try for colder.
Meant to say it's also worth redoing the desiccant. If you send it in to @Bill I expect he may do that for you as well.
Thanks. I definitely will push the temp down some more. As soon as I hear from Bill, I will get my STF in for servicing. I posted the longitude question to the Bisque forum and so far I got one response acknowledging that it is an "issue"
