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Need Some Help Processing Mars Images

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#1 Rustler46

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Posted 20 October 2020 - 06:51 PM

Las week I had a go at imaging Mars with my C-11, f/10 & ASI290MC color video camera. The sampling is around 0.21 arc-seconds per pixel. Here is my work flow:

  • Capture 2-minute videos at 255 FPS, around 31,000 frames (3.2 GB) each using FireCapture
  • Stack in AutoStakkert!-3, default settings 
  • Output fed into Registax-6

AutoStakkert!-3 produces two outputs - one blurry and one sharp. Until I knew better I worked with the AS!-3 sharpened output with the following results from RS-6.

 

Mars-004659-RS-2.jpg

10% (3150 frames) stacked

 

This image would allow very little wavelet sharpening in RS-6 since it had been pre-sharpened in AS!-3. Then I came to understand that the blurry, unsharpened output is what should be fed into Registax. Here is a result.

 

Mars-004659-RS-2.jpg

25% (7880 frames) stacked

 

The problem I need help with is that in the second image, on close inspection, there is a "window-screen" pattern on the left side only. So what is causing this? Should I have done a drizzle in AS!-3?

 

Any Help you can offer would be greatly appreciated. I can supply pertinent settings used in wavelets as the need may be.

 

Best Regards,

Russ


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#2 sunnyday

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Posted 20 October 2020 - 06:53 PM

I can't help you, but I find them pretty anyway, thanks



#3 Tom Glenn

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Posted 20 October 2020 - 07:02 PM

For some reason the images don't open for me when I click them, although I can see them in the forum, but I'm not sure if this is displaying the full size or not.  So I can't see what you are referring to as a "window screen".  Overall I think you are on the right track with processing here Russ, and the results are quite visually pleasing.  One note, is that you only captured for 2 minutes with a color camera, and you can easily capture for 5 minutes (even 6 minutes, I've personally done routinely).  You would then easily increase your total frames by 2x-3x, and this will only help your final result.  Also, what gain and exposure were you using?  Although 255fps is fast, I think that with Mars, shot at f/10 with your gear, you could easily get over 300fps, if not 400, and should be able to capture about 100k frames per video.  



#4 Rustler46

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Posted 20 October 2020 - 07:06 PM

For some reason the images don't open for me when I click them, although I can see them in the forum, but I'm not sure if this is displaying the full size or not.  So I can't see what you are referring to as a "window screen".  Overall I think you are on the right track with processing here Russ, and the results are quite visually pleasing.  One note, is that you only captured for 2 minutes with a color camera, and you can easily capture for 5 minutes (even 6 minutes, I've personally done routinely).  You would then easily increase your total frames by 2x-3x, and this will only help your final result.  Also, what gain and exposure were you using?  Although 255fps is fast, I think that with Mars, shot at f/10 with your gear, you could easily get over 300fps, if not 400, and should be able to capture about 100k frames per video.  

Thanks for your reply. I ran into the same problem. So what I'll do is do a screen-shot of the problem image. 

Screen Shot 2020-10-20 at 5.04.55 PM.png

 

Thanks for your comments, Tom. I just shot enough to keep file size down. I only had 75 GB free SSD space. So 23 videos spread over some 3 hours gave a variety of different seeing conditions and how close to transit of the planet. But the programs (FireCapture and AS!) had a limit of 4 GB. Maybe that's not a limit with later versions.

 

At first I stacked 10% (3150 frames). But someone recommended stacking also 25% and 50%. So I'm a bit rusty with lunar/planetary imaging. But my equipment is up to the task. Planets are just the hardest. Moon imaging is much easier. Here's a recent result on the Copernicus crater.

 

Copernicus-2.jpg

 

Best Regards,

Russ

 

Russ


Edited by Rustler46, 20 October 2020 - 07:20 PM.

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#5 Tom Glenn

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Posted 20 October 2020 - 07:10 PM

Hi Russ, the screen grab has kind of butchered your image quality (artifacts and much darker for some reason)....the smaller reproduced versions above look quite nice!  In general, I've found that those window screen artifacts get better when you perform some combination of the following: 1) stack more frames, 2) reduce wavelet intensity (especially slider #1), and 3) increase (slightly) the denoise value in R6.  


Edited by Tom Glenn, 20 October 2020 - 07:10 PM.

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#6 Rustler46

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Posted 20 October 2020 - 07:25 PM

Here's another screen-shot with my monitor's brightness turned up.

 

Screen Shot 2020-10-20 at 5.22.48 PM.png



#7 Tom Glenn

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Posted 20 October 2020 - 07:30 PM

Planets are just the hardest. Moon imaging is much easier. Here's a recent result on the Copernicus crater.

 

I can assure you this isn't the case, Russ!  Your Copernicus image is fantastic (and I remember you posting it before, and it received much well-deserved praise).  I can guarantee that you would not achieve that same quality result every time you attempted to image Copernicus.  It all comes down to the seeing, no matter what you are imaging.  As I said though, regardless of what is going on with your image displayed above, for whatever reasons, the smaller version at the top of this page look quite good IMO.  


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#8 Rustler46

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Posted 20 October 2020 - 07:35 PM

I can't help you, but I find them pretty anyway, thanks

Thanks for your kind comment, sunnyday. I am quite pleased with them as well. These are by far the best Mars images I've ever gotten. Cameras have greatly improved in recent years. My 12-year old C-11 remains as a good example of the Schmidt-cassegrain design.

 

All the Best,

Russ


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#9 Rustler46

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Posted 20 October 2020 - 07:41 PM

Hi Russ, the screen grab has kind of butchered your image quality (artifacts and much darker for some reason)....the smaller reproduced versions above look quite nice!  In general, I've found that those window screen artifacts get better when you perform some combination of the following: 1) stack more frames, 2) reduce wavelet intensity (especially slider #1), and 3) increase (slightly) the denoise value in R6.  

Thanks, Tom. I'll try those suggestions tonight. I did apply a little de-ring adjustment to reduce the usual edge wavelet artifacts. There are so many permutations and combinations of Registax settings, it can be overwhelming. So your suggestions are much appreciated.

 

Best Regards,

Russ



#10 Jkaiser3000

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Posted 20 October 2020 - 08:22 PM

Just out of curiosity, how was the histogram set during capture? It is my understanding that if it’s too low it’ll produce artifacts when processing due to not enough range of tonality in the data. That tends to produce onion rings but may be worth checking.

 

I would also suggest you stack more than 3000 frames. I’m guessing with such high frame rates you had the gain cranked up a bit, stacking more frames will reduce the associated noise.

 

I also can’t open the images and the screen grabs are really messing with them, the originals look very nice at the reduce scaling in the post but the grabs do show some of the mesh you mention. Not sure what could be causing it other than debayering artifacts?

 

Hope you sort it out, those pics look very promising



#11 Rustler46

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Posted 20 October 2020 - 09:31 PM

Just out of curiosity, how was the histogram set during capture? It is my understanding that if it’s too low it’ll produce artifacts when processing due to not enough range of tonality in the data. That tends to produce onion rings but may be worth checking.

 

I would also suggest you stack more than 3000 frames. I’m guessing with such high frame rates you had the gain cranked up a bit, stacking more frames will reduce the associated noise.

 

I also can’t open the images and the screen grabs are really messing with them, the originals look very nice at the reduce scaling in the post but the grabs do show some of the mesh you mention. Not sure what could be causing it other than debayering artifacts?

 

Hope you sort it out, those pics look very promising

As I recall, it was set around 70% for the brightest channel. The dimmer colors (likely blue) was around 50-55 Of course this was constantly changing with the instantaneous seeing conditions.

 

Gain was at a bit under 50%, since I was running a fairly fast f/10. With that sampling (0.21 Arc-sec per pixel) I recall there were about 105 pixels under Mars' image.

 

Edit:

I checked the settings text file which showed the gain was set at 37% (224). The camera is quite sensitive and apparently low noise, despite being uncooled.

 

As for not being able to open the two original images in the first post, the problem likely lies with Lightroom-5. There were some minor adjustments in that. What happens is LR-5 imports the original file, converting it to Adobe digital negative. When it exports the edited image it converts it back to the format selected. Likely in all of that something is happening that prevents the images from opening on Cloudy Nights.

 

So I'll try posting the second image (straight out of RS-6) as a 476 KB png-format.

 

Mars_004659_lapl6_ap61-RS3.png

25% (7880 frames) stacked, 2020 October 15, 7:47 UT

 

Hopefully this one will open without problems. And yes, these photos look very promising. I'm so excited!

 

Edit:

It seems to load now. It does show the window-screen artifacts on the left side when enlarged.

 

Russ


Edited by Rustler46, 21 October 2020 - 12:43 AM.


#12 Rustler46

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Posted 20 October 2020 - 11:31 PM

For some reason the images don't open for me when I click them, although I can see them in the forum, but I'm not sure if this is displaying the full size or not.  So I can't see what you are referring to as a "window screen".  Overall I think you are on the right track with processing here Russ, and the results are quite visually pleasing.  One note, is that you only captured for 2 minutes with a color camera, and you can easily capture for 5 minutes (even 6 minutes, I've personally done routinely).  You would then easily increase your total frames by 2x-3x, and this will only help your final result.  Also, what gain and exposure were you using?  Although 255fps is fast, I think that with Mars, shot at f/10 with your gear, you could easily get over 300fps, if not 400, and should be able to capture about 100k frames per video.  

Tom, I looked at the text file showing capture settings, I discovered something interesting. It claims that the focal length was 3400 mm. That puzzled me since my f/10 C-11 should have a 2800 mm focal length. Then I thought perhaps the increased back-focus needed to accommodate the ADC and camera body may have increased the effective focal length to 3400 mm, f/12.

 

Perhaps Firecapture "knows" Mars' angular size for any particular date. Then it measures how many pixels are across its extent to come up with an effective focal length. If that thinking is correct, then the sampling is 0.18 arc-second per pixel. Given my C-11's resolution of 0.42 arc-seconds, that sort of sampling might not be so bad given the good seeing experienced during image capture. 

 

Screen Shot 2020-10-20 at 9.29.12 PM.png

 

Just some thoughts. Overall I'm very pleased out how the Mars images are turning out.

 

Best Regards,

Russ



#13 Rustler46

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Posted 21 October 2020 - 01:05 AM

I can assure you this isn't the case, Russ!  Your Copernicus image is fantastic (and I remember you posting it before, and it received much well-deserved praise).  I can guarantee that you would not achieve that same quality result every time you attempted to image Copernicus.  It all comes down to the seeing, no matter what you are imaging.  As I said though, regardless of what is going on with your image displayed above, for whatever reasons, the smaller version at the top of this page look quite good IMO.  

Of course you are quite right about Moon imaging, Tom. I have many poor moon images that are nowhere near as zoomed in as was Copernicus. From my perspective with Moon imaging, if the seeing isn't so good, then less focal length (image scale) hides the effect. You can't do that with planets. If seeing is poor, so are the results.

 

For both my Copernicus and Mars images, the seeing was uncharacteristically good. A few nights before with very poor transparency, the seeing was still very good, giving some of the best Mars views I've ever had. This motivated me to get the imaging equipment all put together, hoping the seeing would still be good. I wasn't disappointed. I'm glad I took the time to clean the corrector lens.

 

Overall the allure of astrophotography is that usually it will reveal way more than you can see visually with the same optics. Lately I've been drawn to EAA (electronically assisted astronomy) as a hybrid of visual and photographic observing. SharpCap Pro serves well in this regard. So far it has just been with a film-era 200 mm telephoto lens and my ZWO ASI290MC planetary camera. Perhaps this fall & winter I'll use my AT115EDT triplet refractor for some of the smaller DSOs. Seeing the image build up before your eyes with live stacking is quite the thrill.

 

In any case Tom, I'm going on to processing that one video, using your suggestions. There are another 22 videos that may have good results. Thanks again for your help! Time to reboot my MacBook Pro in Windows-10 for Registax - more to come.

 

Warm Regards,

Russ



#14 Rustler46

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Posted 21 October 2020 - 02:40 AM

Here's my next attempt using Tom's suggestions.

 

Mars_004659_lapl6_ap61-RS4.png

Mars 2020 October 15, 7:47 UT, stacked 50% of 2-minute video, ~15,750 frames, C-11 f/12, ZWO ASI290MC

 

That seemed to solved the window-screen defect, or at least minimized it greatly. I suspect it is from using a one-shot color video camera with RGB Bayer matrix. This image is pretty much straight out of Registax-6. The only adjustment was converting from TIFF to PNG format. I noticed one change going from 25% to 50% stack. The south polar cap is no longer bifurcated. I guess stacking the extra frames removed that small detail.

 

I'm happy with this one, though the color isn't the best. I tried adjusting it in Lightroom-5 and didn't like the result. I suppose since Mars is still so close, another imaging session with longer videos would be in order. But in all honesty, I greatly doubt that seeing would be as good. Such is a real rarity in my locale. So with another 22 videos to explore, I'm satisfied with what has been captured. After all aren't such activities great for "cloudy nights"?

 

Regards,

Russ


Edited by Rustler46, 21 October 2020 - 02:45 AM.


#15 alphajuno

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Posted 21 October 2020 - 04:18 AM

So, you have the same situation as I do, pretty much.  I have a C11 f10 scope too. As you state, your setup is adding to your focal length.  When seeing is good, you should be able to accommodate an f15, f20 or even f25 set-up.  The compromise is oversampling when using a small pixel camera.  I have the same model camera as you but the monochrome.  After some trial and error, I settled on the Explorer Scientific 2.0 image magnifier which gives an f20 (theoretically) regardless of the image train. That gave a better result than increasing the focal length by placing distance between the telescope and the camera, methinks.  I wish there was a reasonably priced 1.5x barlow or image magnifier out there but oh well.  I had to give up on my 2.5 Televue image magnifier with this camera because it was too much magnification.    

 

I think your pictures are very good and assuming your scope is well collimated, then you should be in good shape as you play around with it more.  My ASI txt files says I have a focal length of just over 7000mm but my guess is that it's closer to 6000mm than 7000mm based on experience.  My image processing starts out about the same as you and I usually use the best 50 percent in Autostakkert3 but sometimes lower. 

 

This image is over processed but that's how I tend to like it smile.gif.  Been imaging more lately than processing...  Seeing was average, a little sloppy.

Attached Thumbnails

  • lrgb2-6-BCs-Mars_002733_l4_.jpg

Edited by alphajuno, 21 October 2020 - 05:41 AM.

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#16 happylimpet

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Posted 21 October 2020 - 04:33 AM

Here's my next attempt using Tom's suggestions.

 

attachicon.gifMars_004659_lapl6_ap61-RS4.png

Mars 2020 October 15, 7:47 UT, stacked 50% of 2-minute video, ~15,750 frames, C-11 f/12, ZWO ASI290MC

 

That seemed to solved the window-screen defect, or at least minimized it greatly. I suspect it is from using a one-shot color video camera with RGB Bayer matrix. This image is pretty much straight out of Registax-6. The only adjustment was converting from TIFF to PNG format. I noticed one change going from 25% to 50% stack. The south polar cap is no longer bifurcated. I guess stacking the extra frames removed that small detail.

 

I'm happy with this one, though the color isn't the best. I tried adjusting it in Lightroom-5 and didn't like the result. I suppose since Mars is still so close, another imaging session with longer videos would be in order. But in all honesty, I greatly doubt that seeing would be as good. Such is a real rarity in my locale. So with another 22 videos to explore, I'm satisfied with what has been captured. After all aren't such activities great for "cloudy nights"?

 

Regards,

Russ

You make a good comment about the detail being lost going from 25 to 50%. I typically use 5 or at most 10% of my stacks. There is always a loss of quality going higher. Of course you need a decent amount of signal. The image is sharper still using 2%, but the noise is too high. The trick is too pick the lowest acceptable %; if you have 22 videos, and maybe 5 are equivalently 'best' you could stack those to recover the noise levels while retaining the sharpness of just using a few % of each stack.

 

Your window screen effect is somehting i occasionally see. Not sure what causes it. carefully increase the denoise for the topmost wavelet levels. But not too much or desirable detail is lost!


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#17 lainev

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Posted 21 October 2020 - 06:09 AM

Not to hijack the thread but Topaz DeNoise AI can bring a little more sharpness. I applied TDN to your image with this result.

Sheet_001.png


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#18 Ittaku

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Posted 21 October 2020 - 06:28 AM

You haven't said whether you're drizzling on not in those first images (I can't click on them either) but I assume you are. The window screen problem is similar to what I encountered that I put down to not enough data being stacked from a colour camera which has far more information coming from the green channel than the others which are just digitally boosted (especially blue). The more images you stack the more it disappears, as well as not drizzling. The way to fix it is to either not drizzle, drizzle less to 1.5, or upsample outside of AS!3 using a different upsampler instead of drizzling. Alternatively if you do drizzle to x3, you will find that if you separate out the colour channels in gimp/photoshop etc there is more detail in the green than the red and blue channels. I used to fix this by applying a gaussian blur of 2 pixels to green and 3 pixels to red and blue. Nowadays I upsample in the gimp instead of drizzling before post-processing.


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#19 happylimpet

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Posted 21 October 2020 - 07:01 AM

Not to hijack the thread but Topaz DeNoise AI can bring a little more sharpness. I applied TDN to your image with this result.

attachicon.gifSheet_001.png

Dont use topaz noise AI for planetary imaging under any circumstances. Yes, it brings sharpness, but it does it by guessing and inventing the original content based on its experience of similar looking images. Its fakery.....its art - the clue is the 'AI'. It is very intelligent, but it isnt quantitative or scientific.


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#20 lainev

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Posted 21 October 2020 - 07:22 AM

I will let those, like you, who are much more intelligent and accomplished than I decide whether TDN is valuable. For me, and I do consider myself to be an uninformed hack, I find that TDN is able to bring an improvement in this particular image without any change or degradation of the data. I have learned something new. Thanks.



#21 happylimpet

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Posted 21 October 2020 - 07:33 AM

I will let those, like you, who are much more intelligent and accomplished than I decide whether TDN is valuable. For me, and I do consider myself to be an uninformed hack, I find that TDN is able to bring an improvement in this particular image without any change or degradation of the data. I have learned something new. Thanks.

Sorry if i came on a bit strong but its something i feel passionately about. There have been some insane uses of it circulated on facebook with people fawning over them, unaware that theyre complete invention.  One image taken with a C14 had detail down to a level of ~0.08" (on a par with hubble), and the image poster claimed it was OK to break the laws of physics to a certain extent!

 

This one is not so bad, and for all i know it may have just deconvolved or done some other legitimate process.

 

Its a shame that the software doesnt promote that it 'invents' detail. It puts it in terms of 'enhancing' and 'bringing out detail'.


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#22 Jkaiser3000

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Posted 21 October 2020 - 10:33 AM

the image poster claimed it was OK to break the laws of physics to a certain extent!

 

rofl2.gif



#23 Rustler46

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Posted 21 October 2020 - 02:54 PM

You make a good comment about the detail being lost going from 25 to 50%. I typically use 5 or at most 10% of my stacks. There is always a loss of quality going higher. Of course you need a decent amount of signal. The image is sharper still using 2%, but the noise is too high. The trick is too pick the lowest acceptable %; if you have 22 videos, and maybe 5 are equivalently 'best' you could stack those to recover the noise levels while retaining the sharpness of just using a few % of each stack.

 

Your window screen effect is somehting i occasionally see. Not sure what causes it. carefully increase the denoise for the topmost wavelet levels. But not too much or desirable detail is lost!

Thanks, happylimpet for your comment. I have had your viewpoint on what is the optimum percentage of frames to stack. No doubt it depends on the quality of the video stream as dictated by seeing. An example of this is the image of Copernicus I shared above. It was a stack of 30% of 10,000 frames. But no doubt the seeing was excellent in that case. 

 

With the Mars images I've shared in this thread, the seeing was similarly good. When I first started processing that video I used 10% (3150 frames) and the result looked good. I was surprised when one experienced planetary imager said I should stack more - 25% and 50%. So I did so and was satisfied with the result. 

 

But for comparison, here is the 10% stack straight out of Registax.

 

Mars_004659_lapl6_ap61_conv-RS1.png

 

Now for full disclosure this image was first sharpened by AutoStakkert!-3 with minimal wavelet sharpening by Registax-6. So the result may be improved if I had worked with the non-sharpened AS!-3 output, using Registax for all of the sharpening. But in any case one can compare the above with others in this thread with more frames stacked. And note the polar cap is split as we have discussed before.

 

I also have a stack of just 1000 frames (3%) that I'll share on the next posting. I'm up against the 500 KB upload limit.

 

Yes, it is a balancing act with image sharpness versus noise in deciding what percent to stack. For myself the jury (of one) is still out, as I compare results with various percentages stacked. I'm just pleased that the seeing was good when I captured the video being explored in this thread. The exciting thing is I have 22 similar videos to play with on "cloudy nights". Your suggestion to stack the best of the stacks is something I will indeed explore.

 

Kind Regards,

Russ


Edited by Rustler46, 21 October 2020 - 03:49 PM.

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#24 happylimpet

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Posted 21 October 2020 - 03:14 PM

Its really nice to have some quality data in the bag, to play with over the coming days, weeks, months and years!



#25 Rustler46

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Posted 21 October 2020 - 03:31 PM

So, you have the same situation as I do, pretty much.  I have a C11 f10 scope too. As you state, your setup is adding to your focal length.  When seeing is good, you should be able to accommodate an f15, f20 or even f25 set-up.  The compromise is oversampling when using a small pixel camera.  I have the same model camera as you but the monochrome.  After some trial and error, I settled on the Explorer Scientific 2.0 image magnifier which gives an f20 (theoretically) regardless of the image train. That gave a better result than increasing the focal length by placing distance between the telescope and the camera, methinks.  I wish there was a reasonably priced 1.5x barlow or image magnifier out there but oh well.  I had to give up on my 2.5 Televue image magnifier with this camera because it was too much magnification.    

 

I think your pictures are very good and assuming your scope is well collimated, then you should be in good shape as you play around with it more.  My ASI txt files says I have a focal length of just over 7000mm but my guess is that it's closer to 6000mm than 7000mm based on experience.  My image processing starts out about the same as you and I usually use the best 50 percent in Autostakkert3 but sometimes lower. 

 

This image is over processed but that's how I tend to like it smile.gif.  Been imaging more lately than processing...  Seeing was average, a little sloppy.

Thanks for your comments, alphajuno. They are much appreciated. I have found if I take the lens set of a 2X Barlow and screw it onto the filter threads of my camera, it gives an effective focal length of f/17 with the C-11. This effect is due to decreased spacing, Barlow lens to sensor.

 

I like your over-processed image. It has certainly has captured a lot of very tiny detail. I particularly like the two little fingers pointing up on the left side. These I believe are called Gomer. My lower image scale barely shows them.

 

The main problem I have with the longer focal length is the difficulty in getting the planets on the camera's tiny sensor. But I'm working on using my piggy-backed 115mm refractor as a finder of sorts. The two OTAs don't point in exactly the same direction, with no provision for adjustment. But with a reticle eyepiece (Celestron Micro-guide 12mm) I should be able to find the position in the refractor FOV that places the subject on camera sensor.

 

I would like to see a discussion of over-sampling. Even with my f/12, the conventional sampling calculators say it is borderline over-sampled. For excellent seeing my 0.18 arc-sec per pixel is near maximum. Your image shows the advantage of over-sampling, with nice detail and large image scale.

 

I have shot as high as f/50 and with decent results. With Mars so bright, what's the downside. Well, of course the answer is number of frames captured.

 

Best Regards,
Russ




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