Magnum

Yes exactly, dithering is beneficial in my view for any camera to get the best image, My mount takes 15 secs to settle after a dither, so the full frame download time is irrelevant for me wether im using the fast cmos or slow ccd, they both have to wait for the guider to settle anyway. Plus I have the main computer handling the guiding and dithering and capture from the cmos, then the other PC handles the CCD, ive calculated the required delay on each so they stay in sync all night . so cmos and ccd running in perfect harmony 😛

not sure how you have come to that conclusion, seems you have ignored what's been said about 4x4 binning and region of interest, both of which can allow for sub 1 second downloads with even the slowest CCD cameras, not to mention that Sony CCD's are much quicker anyway. Although I have an observatory I still focus all of my cameras manually and frame my targets manually, no issue at all. im usually up and running quicker than my friends using auto focusers and plate solving .

I mean in Maxim which has the auto screen stretch like other programs, as soon as the ccd downloads I can instantly see the target even faint ones, but with the cmos I can only see the stars and maybe a hint of the brightest parts of nebulas, o have to do a full DDP stretch to see if im in the correct place, so thats more time consuming than ive lost on the ccd slower down load times. maybe if I used SGP the auto-stretch would work better, I dont know. dont get me wrong I do like the ASI533

Yeah I process on my Mac indoors too. since moving to win 10 which gave me Remote Desktop I actually stack my images on the capture machine in Maxim via Remote Desktop from my Mac indoors, then drag onto they usb stick and close everything down remotely, then just walk out to retrieve the USB stick. next day I can mess around stretching it in Maxim on my Macs win7 VM, then drag that to the Mac desktop to process in windows. 😛 I like to make things implicated but al works really well, and means I can get out of Windows ASAP, and back to the Mac where im most happy.

I honestly dont notice a lot of difference there either, as I get initial focus with both with 4x4 binning in which case both are pretty instant, then drop down to 1x1 binning for final tweak yes that takes several seconds but only takes 2 or 3 subs the get final focus, as for framing targets I also use 4x4 the CCD shows more in 5 secs than the cmos shows in 5 secs. I run 1 camera on each machine at same time, never find the CCD really slows me down much, but im all manual focus , maybe if I had auto focussers then it might be very time consuming waiting for it to do its stuff.

Hi Pete, I was resistant to giving up win7 on my net top too, but ended up buying a nice used i5 Lenovo mini pc for £120 on eBay with win10 pre installed on the SSD. The windows update has bitten me though, I had everything disabled even within the group Policy editor, but still after the first month it somehow broke my Sky6 tell api ascot plugging from connecting to the mount, took me 2 days to fix it and im not sure what I did actually fixed it in the end. Thankfully its been ok ever since. Thought wildly I also got an identical machine for my mate and that broke the same driver about 1 month after mine, and even though I tried all the same things ive never bee able to get it working again, so he has to use carter de ciel now. I have no need for future updates as its purely a capture machine which I control on my home network vie Remote Desktop. Good thing is this machine runs so fast, it boots in about 4 secs and I can stack about 100 ASI 533 subs in less than a minute. kept the net top as a backup, as that still runs all the cams ok on win7.

Hi Pete, I own an Atik383 same sensor as your QSI and ive owned a ZWO533MC for 11 months, with good cameras that compliment each other well. Personally I would avoid the 294MC as the effects of starburst amp glow are a complete shock to the system and contrary to popular belief just subtracting darks doesn't completely deal with the effects of amp glow, yes the the glow disappears but what remains in that area will be greater noise, Steve Chambers from Atik has a great simple explanation and demonstration in the video below using the Atik Horizon cmos. Now for me I couldn't see any point in buying a camera that has such strong amp glow when the latest generation of ZERO amp glow sensors are available, which is why I went for the 533. If I had more money its larger brother the 2600. It Just seems crazy to go from a CCD sensor that is so clean and glow free to a sensor that has massive glow. Also the 294's can suffer with strange coloured blotches in the Flats and lights, especially when using dual narrowband filters. The 533 and 2600 are as close to CCD files as ive seen from a CMOS. I can take 15 min subs with the 533 and still not see any Amp glow. ive used the hundreds of short subs method with it and also tried my standard CCD exposure times and cant see much difference in the final stack, so I normally go for longer subs to minimise storage and processing time ( as im the laziest imager ever ). in fact for me the short subs have a rarely talked about draw back of fixed pattern banding noise that isn't present in longer subs, I recommend not going shorter than 30-60 secs if you want to see clean subs. Nearly every discussion about CMOS concentrates on the low read noise allows shorter subs to give an advantage and while in theory this is true, ive found in real word use the lack of dark current and fixed pattern noise is far more important to me. The reason for this is that even comparably high read noise of the noisest CCD cameras will easily get swamped in even the slightest light pollution by shot noise. While fixed pattern noise on the other hand does not. So if I take hundreds of 10 sec shots that all have a banding in them, when I come to stack them the pattern will actually become more evident rather than decrease hence the absolute need for dark frames to compensate ( also shown in Steves video ). If I take subs of over 60 secs each they show no discernible banding at all, hence I never use darks with my cmos camera and have never seen any benefit from using them, as long as I use long enough subs. So I simply dither my long subs and get perfectly clean results. In short read noise isn't important to me at all, even in narrowband there is enough light pollution getting through to swamp even the highest read noise. Finally id like to Add that the claimed higher sensitivity of cmos cameras never really manifests itself to me in the real world except when doing high frame rate planetary imaging. Prior to the 533osc I owned an ATik428osc and I have pretty much identical subs taken with both and for the same sub lengths there was very similar signal picked up with both on faint targets, I really cant say one is better than the other, actually the only reason I switched was that the 533 is a bigger chip for the same price. My supposedly ssllooww Kodak Mono sensor is still much faster than either. I will probably get loads of hate now, but I prefer to go on my own real world tests than popular opinion. Id recommend the 533 or 2600 over the 294 any day. Lee

Thats much better Olly, the non circular stars was the thing I noticed first like Vlaiv, and was really distracting for me, but assumed it was a guiding issue. weird how the central star seemed more effected, is that just a function of brightness on the diffraction ? Though like you I still didn't get the forest Gump reference, but now I think its a really great one 😛 and I going to use it myself in the future hahahahahaha. Im really enjoying watching how you transition to cmos Osc imaging, as you know im on a similar journey with my 533, but dont think I can ever give up the mono Atik ccd's. Lee

Captured this wide field view of the Bubble nebula and friends, including Sharpless 157 the Lobster Claw Nebula, Open cluster M52, and at lower right The star forming factory of NGC7538 home to the largest yet discovered Protostar which is 300 times the size of our solar system. Also in the image is the Nova Cassiopeia 2021. Capture details: 40 x 5 min subs with my ASI533MC cmos camera + Triband filter & Sharpstar 61EDPH II f4.5 triplet refractor. Guided, captured, stacked,and DDP stretched in MaximDL, processsed with Photoshop. No Calibration frames.

That's interesting Olly, when you say background level of 21 do you mean ADU or photoshop levels? I presume the later. I always pre stretch my images in MaximDl with DDP and make sure I have a big gap on the left of the screen stretch, then save to tiff before opening in photoshop so the background is already at a high starting point then I bring it back down at the end of processing. Be interesting to see what the average ADU of your bias frames are, mine are about 350ADU with my 460, if that helps? Lee

The amusing thing is, although the people that say CCD is dead also say that they are worth hardly anything on the used market, yet in fact prices of used CCD's seem very stable and if anything have actually gone up recently. I know I cant replace my 460 and 383 for less than I paid for them 2 years ago. Despite those people trying to tell us otherwise in a vain effort to try and make it happen. Same people also say that the large pixel size of CCD is unsuitable and grossly under sampled when using short focal lengths like camera lenses which will result in awful blocky stars 😛 well here are 3 taken with 135mm lens at 9"/pixel , looks ok to me even though those people tell me im wrong 😛 Sorry ive hijacked the thread, but its still about the 383 LOL

Replying to myself here as I forgot to mention that most of what look like hot pixels in the 383 darks are not true hot pixels at all, if I measure mine 95% of them read around only 900-2000 ADU So that would be considered a warm pixel, a true hot pixel would be maxed out at 65,000 ADU. Now If you take a Dark it can look scary seeing lots of bright dots against black, but as you can see in my single 900 sec sub above on a real target, most of them aren't visible at all and the ones that are visible are clearly not white and dimmer then most of the faint stars. This explains why they soon stack out with no special intervention on my part, just a very slight dither and stack with median or SDmask in maxim. Conversely when using the Sony sensor in my Atik 460, yes it only has maybe a dozen hot pixels, but they tend to be true hot pixels ( ie maxed out 65,000ADU ) that take much longer to stack out and require more dithering to do so or more subs in the stack. I think this is why a lot of the experienced ccd imagers Like Olly and Sarah Wager really appreciate the Kodak sensors. I can can literally make a perfectly clean image from 4-5 long subs with the Kodak sensor in my 383. ignore what the darks and focus frames look like just trust the data and you will be amazed at its quality. As much as I like my cmos ASI533MC I could never make a final image with it in only 5 subs lol, it needs at least 50 -100subs to get really smooth. Problem with that is it uses a lot more storage but even worse it takes many times longer to stack, and as im probably the laziest imager ever I find that rather tedious. Having said that, the 533 is probably a better camera than any OSC ccd ive used for trying to produce a colour image in 1 night, but not a match for the Kodak mono chips in ultimate quality of the data. sorry im starting to turn this post into a cmos vs ccd debate, I will just say on that they are both good technologies, I just get sick of the FB crowd from a certain uk retailer saying CCD is dead 😛 well if they dont want them I will gladly take them all off their hands 🙂. Lee

very nice and I can see the strawberry, I really like the image, except for 1 little point if im being picky I can see some diagonal walking noise in the lower left 1/4 of the image, ive noticed I got this when I first started using my ASI533, in my data if I dont dither enough, just the nature of fixed pattern noise in cmos I think. but as soon as I increased my dither amount it completely vanished, and not had to deal with it since. Cheers Lee

Not old school at all especially as the 383 is still a current model while Atik supply of of 8300 sensors lasts, and now retails for £2 grand. I wouldn't give up my mono CCD's for any cmos even though I own an ASI533 OSC cmos which compliments them. the 383 is an amazing camera and the 8300 sensor is probably the cleanest Kodak/ on semi sensor ever made, if cooled properly to -20c and running on the recommended 15v power supply my 383 is as clean in 10 min subs as my Atik460 with sony sensor ( but not as good with short subs ), barely any more warm pixels than the Sony chips. both are far cleaner than say an ASI1600, and miles cleaner than any of the 183 / 294 Starburst gen cmos sensors. the importance of lack of fixed pattern noise and Amp glow is much more important in real world imaging than sensitivity and read noise in my opinion. The only cmos I think get close are the latest zero amp glow models like the 533 that I own, but even with that dithering is much more important to deal with the fixed pattern noise. Ive taken single 30 min subs that look like a final stacks from other cameras . Sorry I just love these cameras Lee

Im really disappointed in you Steve, that you could mistake the absolute Classic movies Raider of the Lost Arc, for a Batman movie! tut tut 😛

well done Carol, tried this last week with my Samyang @ f2.4 + my ASI533mc from my garden bottle 5/6 but could only get just the iris, even in massive stretch I could barely see a hint of the strongest dark neb on the right. I think I will have to try again with my mono 460 or 383, though I was really hoping the OSC would work on this as ive seen may people getting a good image using OSC, maybe they have darker skies than me. I do fine with narrowband or goalies just never really get anywhere with dark nebulas / IFN. Lee

Thanks, I have posted a few others in the last 2 weeks with this combo if you are interested. Lee

I used to own one back in 2012, mine came with a disk including MaximDL light, Still use MaximDL today albeit the v5 pro suite and with every camera since then, ive never found anything that I prefer or does a better job for capture and stacking. the H9C was an excellent camera, and besides the small size isn't really inferior to the latest sensors in my opinion.

NGC7000 the North American Nebula in Cygnus. 25 x 5 mins with my ZWO ASI533MC cmos camera + Altair Triband & Samyang 135mm lens @ f2.4, tracked on the EQ8. Guided, captured, stacked & stretched + DBE in MaximDL, no calibration frames. processed in Photoshop.

Between 5 and 6

Excellent

Tonights capture M31 the Andromeda Galaxy wide field. 30 x 90 secs with my ASI533MC cmos ( gain100 ) + Idas LP2 filter & Samyang 135mm lens @f2.4. Guided, captured, stacked & stretched in MaximDL, final processing in photoshop. No calibration frames. Lee

Me too with the Samyang F2 but its normally working at f2.4. Usually doing close up at the same time with one of my other 3 scopes on the rig.

Hi Olly, I presume you have already Seen this on the ZWO site on what they recommend. https://astronomy-imaging-camera.com/tutorials/which-debayer-algorithm-is-the-best-for-asi-cameras.html I download the trial of APP to try it, but found I could already achieve the same in MaximDL5 just by playing with the combination of high quality & Under sampled check boxes in the debayer window, Maxim still impresses me even though its ancient now. Lee

You are getting the hang of the new setup fast Olly, what gain an offset are you using? Lee