Magnum

10 minutes ago, TakMan said:

I always gave the mount 20 seconds to dither and settle before starting the next exposure. Now the 18 seconds for my Atik to download is used efficiently to perform that task, so I only ‘waste’ an extra 2 seconds for the mount to settle. I fact the exposure could start immediately, I have chosen to add that extra time just so the there is no USB conflict between the download and the guide exposures….

I’m sure the new CMOS cameras are ‘better’ than the sensor in my camera, but the argument of download speed is somewhat mitigated for me. Even if I changed sensor to one that downloaded in a second or so, I’d still want another 10 just to allow the guiding to settle…. so that means I’m currently only loosing out by 8-9 seconds, nothing in the grand scheme of things when each exposure is 10-20 minutes.

And thinking about it, if you’re running 2-5 minute CMOS exposures and dithering after each, then waiting for the mount to settle, the difference between CMOS and CCD, purely in the ‘download speed’ argument is a none issue…..

Damian

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 😛  

19 minutes ago, ONIKKINEN said:

This talk of 10-30 sec download times is completely alien to me, as i never had a CCD as a new astrophotographer. What i can take away from this is that this is another reason why astrophotography is becoming more forgiving and beginner friendly without the need for maybe such extreme cashflow to keep the hobby going (still expensive though). This thread makes CCDs sound very observatorey while CMOS is pretty plug and play, and not that different from DSLRs with actual live views. Focusing with 0.05 fps sounds like a nightmare for manual focusers, especially if the scope is not in rough focus already. I took the live-ish view for granted!

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 .

1 minute ago, tooth_dr said:

I dunno if that’s my experience of the CMOS showing less than the CCD.  In my 2-3 years with several KAF8300s then an overlap to CMOS using both for a while then now full CMOS, I honestly can’t think of a single advantage.  Some things are equal, but I’ll never go out any buy another CCD. 

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

6 minutes ago, gorann said:

I do run my Mesu 200 and PHD2 on a Win 7 laptop (that is never on the net) but for the cameras I use Win 10 laptops and have them in airplane mode (since I have had them shutting down to upgrade). Then of course, to complicate it all I do all my processing on a Mac.......

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.

12 hours ago, tooth_dr said:

100% agree with this. It doesn’t sound long but waiting 10s for a frame to download is frustrating when focusing or framing.  

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.

2 minutes ago, petevasey said:

Thanks Gorann.

I actually went down that route a few years ago when I bought a refurbished Dell D620 from Val-U-computers in the UK.  And very good it has been, including a true Serial port - very useful!  But I would actually have to buy TWO computers - I have one permanently in my Observatory and use the laptop for star parties etc.  My Obsy computer is a little Net top, for which I have a spare.  I also have a Netbook.  All Windows XP because my astro kit all works seamlessly with it.  If it ain't broke, don't fix it!  Even if I went for more powerful machines, I'd probably still try to have Windows 7 - I don't like the way 10 forces upgrades which seem to always screw up drivers etc.  But of course I don't know if W7 will run USB3.  Heigh Ho!

Cheers,

Peter

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.

On 30/10/2021 at 17:48, petevasey said:

Hi, all,

For almost 12 years now I've been imaging with my QSI683 wsg camera.  8-way filter wheel, built in off axis guider, good sized CCD chip.  And of course getting good results.  But friends of mine are using the ASI533 one-shot colour CMOS camera, and rave about it!  Very sensitive and with the appropriate multi band filter appears to take good narrow band type images.  So I've been browsing similar cameras, and believe the ASI 294MC Pro will nicely fit the bill - almost identical chip size so no problems with flat fields, very sensitive and not a huge pixel count.  I believe there may be some amp glow, but that's easily taken care of with darks.  I'll be using Windows XP, but tests with one of the 533 cameras were successful, so hopefully the 294 will also run ok.  I'd probably try and persuade a supplier to do me a sale or return so I could confirm that all is well.

BUT...  Although a one-shot colour is very tempting - it would seem that with the high sensitivity these cameras can considerably reduce total imaging time even though binning is not possible, nevertheless will a change really be worth it?  Any comments?

Cheers,

Peter

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

On 03/10/2021 at 07:52, ollypenrice said:

@vlaiv

😁lly

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.

3 minutes ago, ollypenrice said:

Out of interest, I do have an issue with my 460. I struggle to get the background sky up to the 23 I like to see, as measured in Photoshop. What I find is that my background sky is made up of pixel values ranging from a lot less than about 21, up to and including 21. If you like, it's more a cool pixel problem than a hot. My workaround is to get the brighter background pixels up to 21 and then pin the curve at 21, put fixing points above that and stretch below it, not hard enough to remove all grain.

I image at a dark site, which might be relevant, and still like my Kodak chipped camera since saying I did early on this thread. I'm not using it because I've lent it to one of my robotic clients but it's still beavering away.

Olly

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

1 hour ago, gorann said:

The CCD cameras are of course not dead, it is just the market for them that died, so Lee, you should go shopping and give yourself a Christmas present, maybe get more real estate than the 383🧑‍🎄

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

On 21/04/2021 at 00:39, Magnum said:

Thought I might as well sow the quality of data the 383 produces when used at 13.8volts @ -20C, ive attached screenshots of uncalibrated single 900 sec subs of the Pelican and Heart nebula's both at 100% to show how clean the subs are, and also the final images which are both only 15 x 900 secs each using just bias frames and dithering.

Please don't give up on the camera unless you want to give it to me really cheap LO 😛

Lee

 

 

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

On 17/09/2021 at 15:06, assouptro said:

Hi Stargazers

I am an Atik fan. 

It seems quite old school, most of the images I see these days on this forum are from CMOS chips but there are some older CCD cameras now available second hand at really good prices! 

 

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 

5 hours ago, FLO said:

That looks like something out of a Batman movie! 🦇

Think smaller, lighter and brighter with white walls, blue & orange racking and a mezzanine floor 🙂

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.

5 hours ago, SteveNickolls said:

Thanks for posting. Could you say what Bortle class you were imaging in?

Cheers,
Steve

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