Uncle Rod Uncle Rod's Astroblog: http://uncle-rods.blogspot.com/
Quote:Hi Craig:Another DSLR vs. CCD head to head would be great...
Quote:Since these are not meant for planetary imaging, the fact that, for very short exposures, the odd and even lines come from different exposures some time apart is not a significant handicap.
Quote:Great review. I'm not sure I understood the part about the odd/even line scans. Are you saying that it takes 2 minutes to get a 1 minute exposure because it is actually a composite of 2 images?
Quote:1. I wasn't clear as to why these are not meant for planetary imaging ; and 2. What technology would be recommended for planetary imaging?
Quote:FWIW, I finally am making some progress into the image processing Canon is doing on the images before they hit the CR2 file. I've suspected they're doing both scaling and shifting of the data but the evidence was more indirect. Now, it's pretty clear. They're doing it for a solid reason and one that makes sense for the target audience of normal photography. But, it does make things a bit tougher for the astro crowd.Craig
G11/Gemini-2/OPWB Canon 60D (unmodified) with 18/55mm kit lens and "nifty fifty" lens Assorted M42 screw mount lenses (28mm thru 300mm) Celestron 102GT refractor (Costco special) 8/10 inch astrograph someday. DeepSkyStacker 3.3.2 StarTools 1.3 http://www.astrobin.com/users/StarGale/ http://everettastro.org/
Quote:My impression is that different astro software extracts canon raw files in different ways - and some might be better than others. One time when I messed with this stuff, Maxim seemed to do an ok job - compared to other things anyway. I haven't worked with the canon sdk myself, but I believe there are many ways to extract the "raw" data from the .cr2 files - and it has to be done right. Unless the extracted values are "raw" - the whole calibration process is a song and dance that won't make mathematical sense - and would make it hard to compare ccd with dslr.
Quote:Does this mean you can stretch the DSO images much further from a QHY camera than a DSLR? Does this mean I can get the same results from a QHY camera with a fraction of the integration time? Regardless of the advantages, would you still recommend a beginner like me should stick with a DSLR for a while?
"Telescopes are forever"
Quote:Question for you.Q: will the deeper wells help prevent star bloating.Q: will the deeper wells help with color depth.
Quote:I spent several days analyzing things and it's clear that Canon is both shifting and scaling the data before it hits the CR2 file. I've got about a 12 page report ready to put up here but that conclusion seems undeniable.Running Canon's or Adobe's recon is really adding a ton. If you run:"dcraw –D –r 1 1 1 1 -4 –T IMG_1000.CR2"
Bay Area, CA Stellarvue SV4, SV70ED Orion 127 Mak, ST80 Pentax K10D (full spectrum mod with cooler) Losmandy GM11 with Gemini 2 My Astrophotos on flickr and on Astrobin and where I write about my efforts