Rusted

I'm back. Started at 8.00 capturing lots of short [mostly] 500 frame videos and a few 1k.. Stacking only 100 in AS!3. Then ImPPG. Between 8am and 9am the seeing wasn't great. It improved after 9.00 as the sun gained altitude. Using 800x600 frame size in SharpCap with 2x WO Barlow on the ASI174. Had to change to the PST BF for increased prom contrast over the Lunt B2000S2. The PST BF allows much lower gain and shorter exposures. The seeing went bad again after 10.00 Not proud, but the best I can do this morning.

Thank you both for all your helpful advice. I'm sure it will also be useful to a much wider audience. You have given me plenty of different things to try now and to think harder about what I am doing. My previous imaging routines had become rather inflexible. Usually 40% of 3k and lots of wishful thinking. Suitable only for perfect seeing conditions with my 150mm/ 6" aperture. Your expertise clearly shows that I was making far too many false assumptions. I was convinced that 1-2ms was the only way to freeze thermal, image movement. That huge video files were a good thing. Now you talk of 10ms and much smaller numbers of frames. Tomorrow offers yet more sunshine for me to practice what you preach. Though it may be slightly premature to suggest that you will be astonished. Thanks again.

Thanks Freddie. I preferred the 100 frame image on the full image size but it was a difficult choice. I am really struggling to get exposure and Gain low with my 2x Barlow and 640x480 frame size. I'll get rid of the Barlow and try a larger frame size. The image is boiling madly at this scale.

Continuing on the topic of number of stacked frames: First I captured a 2000 frame video of today's SE prom in rather poor seeing conditions: I then ran it repeatedly through AS!3 [Autostakkert] using increasing numbers of stacked frames. The results were then passed [identically] through ImPPG and finally cropped in PhotoFiltre and assembled into one image To my eyes the 100 from 2000 frames offers the best prom detail: More frames becomes progressively softer. Fewer frames exaggerates noise. I gave each image a file name showing the number of stacked frames. 10fr, 100fr, 1000fr, etc.

Thank Freddie. I haven't really used the adaptive settings in ImPPG. I will certainly have to give them a try. Until now I was never sure at which point the exposure time limits the thermal agitation I see on the monitor. My concentration on ultra-short exposures has been at the expense of increased gain. You and Merlin have both given me a number of things to try. We shall see which approach works for me. Once a video is captured it can be manipulated in a number of different ways. But now it is time for my dinner. Thank you both for your input.

Thanks to you both. Well, now I have just had to delete my initial response to Merlin. I really liked the darker backgrounds but saw the 10 frame example as rather "overdone." It lacked the "smokey" subtlety of the other two. Now I look again it may have slightly more detail. I ran the same video through a new download of AS!3. Previously I had AS!2 on my imaging laptop. Nothing was changed between runs except the number of stacked frames. ImPPG was left open to ensure no change between separate runs. Out of respect to both of you, as experienced and successful imagers, I really ought to have another trial. This time with a completely different video with a wider variety of stacked frame numbers. I can even leave ImPPG completely out of the equation and post the resulting stills separately and unchanged in size or cropping. Which might easily have resulted in unintended changes in these posted examples.

Okay. Three stills from the same video with identical, but minimal processing and with different numbers of stacked frames. The most obvious difference, to me, is the darkness of the background with 1000 of 2k frames. I manually cropped the individual frames around the prom but couldn't make them identical.

Thanks. As I have the videos saved I can run them through AS!2/3 using various % stacks. They will, of course, be dependent on the original video settings: Re: Gain and exposure. I'll be back.

And another: 2.6ms, G262, 100 of 2k. More subtlety to the "smoke."

Thank you gentlemen. I shall apply your advice depending on my target. Proms v surface features. EDIT: Image attached: See label for details.

Thanks again. Don't apologise! I just can't seem to cope with Firecapture. I learn more every day. Usually, the lesson is how little I know. Thank goodness for helpful experts like you! You are our patient Sherpa on the steepest inclines of the learning curve.

Really excellent! You just raised the bar for awesome! BTW: NASA say they want their kit back when you've finished with it.

Thank you Peter. Sheer genius as always. Cough: Be I ever so humble... and I'm not being flippant... but have you see this mod? Easy Alt/Az Mount Modification It brings the telescope's mass down to the altitude axis rather than tottering over the top. So variations of altitude no longer upset the mounting's balance. No tools? You could probably whip this up in 5 minutes with a butter knife and a bit of kindling. PS: I had never seen an AZ3 until I did a search. PS2: Don't kill the messenger. Regards, Sorcerer's Apprentice. 3rd Class.

Really? Thanks. The obvious questions are: Where does the 189 figure come from? As I use SharpCap, do I set that to 189 in the Gain box? Or some other figure? EDIT: SharpCap has no Gamma setting.

Thanks Freddie. All taken on board and I will be following your advice. I think the three SGL medals speak for themselves.

Thanks Freddie. I still see myself as a beginner at imaging. Always open to advice from an experienced imager. My routine solar capture is now 3k frames. Of which I choose 40% if the seeing is reasonable. [Early morning.] If the seeing is very "mobile" I may capture 2k or even 1k. Then I stack 30%. I was advised to stack far more frames when I mentioned how few I was normally using at first. 5-10%. The theory being that I was losing lots of potential data. I am always wide open to experimentation. So will try stepped variations of gain and exposure times. The same with stacking. Thanks again for your patience in responding to my posts.

Thanks for the constructive advice Freddie. I read somewhere that the ideal Gain for my ASI174MM is 300. Previously, I would use zero Gain and adjust the exposure length accordingly. Often that would be around 1ms with the PST blocking filter. Then I changed to a Lunt B1200S2 blocking filter which is much dimmer. So I began to use far more Gain in an effort to keep my exposures short to freeze the thermal agitation. Today I was struggling for clarity in indifferent seeing conditions. There was hidden detail at the threshold of visibility but of relatively low brightness. So I pushed the processing a little harder to bring out that detail. I'd much have preferred greater clarity to bring the "smoke" out without forcing it. I captured lots of videos, over the coarse of this afternoon, but they all looked very similar by the time they were processed in ImPPG. I have appended a "Snapshot" of the prom as seen by SharpCap. No processing at all. This is exactly what I was seeing on my monitor. There is a lot of noise.

2x WO Barlow, 800x600 in SharpCap. 3.37Ms, Gain 300, 250fps. Seeing slowly improving but wind picking up. AS!2, ImPPG, PhotoFiltre7.

Superb image!

I'll give it five minutes before your "time portal" flattens somebody or something! 😱 The nearer a screen is to the light the smaller it has to be. Perspective is your friend. The smallest object would be a bullet but is rather frowned upon in some neighbourhoods. A little experimentation, at night, would go a long way toward establishing non-lethal, minimum screen sizes. That fence is crying out for a single, detachable post [say 2x2?] with a minimum sized screen attached. One which can be easily lowered when not required. Sailors are apt to enjoy a pulley system and mast. With a rise and fall screen but you are definitely on your own there. I'd be thinking of a light frame with black, open weave, cloth screen. Wire coat hanger fodder? A knitted screen perhaps? Or shade netting in a suitable number of layers to achieve nocturnal bliss? Two or three, long, galvanised bolts through the fence crossbars should hold a suitable post. With galvanized nuts and washers for speedy elevation and later dismantling. The screen could be stored flat on the fence in a tasteful horizontal mode. Modern lamp heads are very unlikely to be suitable for super-magnet-ic screen attachment. Otherwise a much smaller and lighter screen might have been attached directly at short notice. A suitably tall, telescopic attachment pole can be obtained for ladder free, window cleaner's use. I do not recommend you try to envelope the entire light head with a spare, bin bag. It might lead to unwarranted accusations of frippery from concerned citizens. When I were a lad... the council would shield street lights from the bedroom windows of sensitive souls. Alas, they were distinctly "uncooperative" when asked if they would shield my lawn. Grr?

An Update: I managed to send SharpCap captures to "E:\" the external T5. Though it wouldn't let me choose a filename. "SharpCap Captures doesn't exist." I measured the capture speed to the external SSD using SharpCap. 400MB/s is plenty. Thanks again for your help.

Thanks to all those who responded. RayD provided the precise information I needed to solve my storage problem. Extra thanks must go to RayD. You may have saved me having to buy a bigger internal SSD. I'm not sure if there is a huge difference in storage speed between internal and external SSDs. For my transfers between the Samsung NVMe MZVP256 internal and the external T5 SSDs I average about 320MB/s. This may be an entirely different mechanism from direct capture to file storage from the camera via SharpCap. I regularly see ~400fps during 640x480 captures from my '174. Presumably the external T5 will be fast enough to cope via USB3? Samsung claim 540MB/s but I never see that during transfers.

Under "Storage" in Windows10 on my laptop I have all new Videos sent to my external Samsung T5 SSD. Everything else goes to "C". The problem is that none of my captured videos ends up in T5. It all ends up in "C". Does Windows recognise SharpCap videos as such? Or does it think of them as "something else." I'm having to send SC captures to the T5 manually because my laptop only has a 250GB SSD. So it keeps filling up during an average imaging session. What am I doing wrong? Thanks.

Thank you very much! You have clarified a great deal which had escaped me. I should probably watch a YT video or two of the whole process before proceeding. I keep having to back up my SSDs to a 4TB external disk hard drive to make room on those. It takes forever and the 4TB HDD is nearly full! I'd better do something and soon!

Thanks Dave. I had to look up Bootcamp partition. None the wiser, but you do have my respect. As stated elsewhere, my ignorance of modern computers is only exceeded by my ignorance of the niceties of image processing. Oddly, my first and second real jobs were with computers the size of sports halls. I was also an early adopter of the Sinclair ZX81. I wrote all my own ray tracing, optical design software on the BBC-B in the absence of anything free being available. It all went rapidly downhill from there.