Help required - Planetary Imaging, Processing

[Pankaj]

Hello Everyone. Wanted to learn how to image and post process planets. Is there a complete tutorial somewhere from which I can learn. I have the following equipment which I wanted to use in the initial phase. Will try my hand on unguided imaging first. It will be nice if someone can suggest how to image, stack and process the pictures. Which software to use etc?

Mount - NEQ6 Pro

Scope - 10" Newt F5 with a 2x Barlow

Camera - Canon 1200D Unmodded

[Cosmic Geoff]

There is plenty of information online.  Or look at the images in the Planetary Imaging section of this forum and see what kit & software were used. Or buy the book "Guide to High Resolution Lunar & Planet Imaging" by Dave Eagle. (www.star-gazing.co.uk).

You will not need to guide unless your mount fails to cope with a highly cropped region-of-interest.  You will probably need to buy a dedicated planetary imaging astro camera - DSLRs are not ideal.   

[PeterCPC]

Sharpcap will be fine for capture. Try AS3 to stack the images with tweeking using Registax. As Geoff says you will need a high frame rate planetary camera like a ZWO ASI224. Guiding is not required but a flip mirror does help.

 

[WolfieGlos]

I’ve just bought a Astro camera with the intention of trying some planetary. Got the Moon (briefly) but clouds otherwise have prevented me trying.

But I’ve been referring to this amazing guide on CN a lot, hopefully it helps

 https://www.cloudynights.com/topic/812022-planetary-imaging-faq-updated-january-2023/

 

[Pankaj]

1 hour ago, WolfieGlos said:

I’ve just bought a Astro camera with the intention of trying some planetary. Got the Moon (briefly) but clouds otherwise have prevented me trying.

But I’ve been referring to this amazing guide on CN a lot, hopefully it helps

 https://www.cloudynights.com/topic/812022-planetary-imaging-faq-updated-january-2023/

 

This was an indeed a very interesting read Chris. Since I am well versed with DSO imaging, hence understanding it wasnt a problem. After reading the article, most of the queries have been answered. I am writing below the flow that i understood with some queries. It'll be nice if someone can clarify-

1. Unlike DSO shooting in stills, I have to shoot a video for planetary imaging. No stills. Right ?

2. Canon 1200D is not a suitable camera for Planetary imaging, but still I will give it a try to start with.  Hope that is fine ? I understand that this camera will shoot only 50 FPS as apposed to 100 FPS offered by dedicated Planetary imaging cameras. So will it be ok if I were to take more number of videos to increase the number of frames?? Does that sound ok ?

3. Once I have recorded all the videos, all these vids can then be uploaded on 'AutoSurface' or 'Autostakkert' for stacking purpose. Right ? 

4. Once the stacking is complete, then I will have to process the image in Registax (like I do for DSOs in PS) . Right ?

Anything I have missed ?

[Elp]

Record videos mainly, with a DSLR you have no choice as it's stills capture will be no where near fast enough, video is also often compressed unless your camera records video raw (very unlikely). When I use my planetary camera I usually capture as images as I can see the images being captured as they're written to disk, video can sometimes error which can corrupt the file (you shouldn't get this issue with a DSLR, very unlikely).

You are limited in time to how long you can record for, due to the target planet rotation, look it up. Jupiter is something like 2-3 minutes, other planets are slightly longer. This can be somewhat mitigated with post processing in Winjupos.

Once the image is stacked with a minimal amount of the best frames you can post process however you like, whether using wavelets in registax, or a deconvolution method in PS or equivalent.

Just attempt it first, the first stumbling block you'll have is focusing, then exposure level, then centering and keeping it in the field of view even with a tracking mount, especially with a Barlow. No amount of reading will account for attempting these things in person.

Edited September 2, 2023 by Elp

[Pankaj]

Thanks for all the help. You rightly said that I’ll have to attempt things first. 
just one re confirmation - you are also suggesting that with a Dslr I should shoot 2 min vids (if Jupiter) and then stack these videos. Hope I understood correctly ?

[Elp]

You don't stack the video, though you can stack/layer the results of each after if they align with their surface detail. The software breaks the video down into its individual frames (25/30/50/60 FPS) and then sorts them into the best seeing quality order, then you specify the percent or how many of those frames to stack. You may be able to input multiple video files, I've never done it this way, if the planet is in all sorts of positions in the FOV (due to bad tracking or adjustment slewing) you may also get stacking artifacts.

Edited September 2, 2023 by Elp

[WolfieGlos]

3 hours ago, Elp said:

Just attempt it first, the first stumbling block you'll have is focusing, then exposure level, then centering and keeping it in the field of view even with a tracking mount, especially with a Barlow. No amount of reading will account for attempting these things in person.

This. I was surprised how hard it was just for the full Moon. I did try it with 72ED, and found the focuser didn’t have enough travel for a 2x barlow so had to remove it. Even then, with the 585mc it was only just in focus with all nosepieces at their extremities in the clamps.

The video lengths to avoid blur from the planet rotating is actually given in that FAQ I linked to CN, and yep, Jupiter is 2-3 mins. 

[inFINNity Deck]

Hi Pankaj,

Important is to know when you achieve the maximum resolution, which you can find in my white papers on the topic:

https://www.dehilster.info/astronomy/optimal_focal_ratio_part_1.php
https://www.dehilster.info/astronomy/optimal_focal_ratio_part_2.php

In short it comes down to that the focal ratio can be about 3 x the pixel-size of the camera. If I understand well the Canon 1200D has a pixel-size of 4.3 micron, so optimal sampling is done at a focal ratio of about 3 x 4.3 = f/12.9. Theoretically you could go as far as 3.7 x 4.3 = f/15.9, but seeing will limit this rule to about a factor 3 (at least at my location, not sure about yours in India). For your scope this means you could use a 2.5x or 3x Barlow. There is no need to guide, I have seen plenty examples of great planetary images using 'manual driven' dobsons. Please note that exposure times go up with larger Barlows.

When using a dedicated camera like the ZWO ASI174MM and filters, you may achieve frame-rates up to about 200fps in FireCapture. These 'videos' can be stored in uncompressed SER-files, which then can be read and processed using AutoStakkert!3. On my website I usually explain the settings I use for this in the planetary section (you will also find the lengths of the separate recordings there):

https://www.dehilster.info/astronomy/mars.php
https://www.dehilster.info/astronomy/jupiter.php
https://www.dehilster.info/astronomy/saturn.php

Post-processing I usually do in PaintShop Pro, but I believe that the majority does that in PhotoShop.

If you want to use the Canon, I suggest you capture in highest resolution and maximum frame-rate. If that means you have to image separate files instead of AVI or other movie-format, you can use PIPP to create a SER-file from those separate images, which then can be processed in AutoStakkert!3.

Please note that collimation and focus are key in planetary imaging. I always check my collimation on a nearby star and focus using a Bahtinov-mask on either the moons (in case of Jupiter) of a nearby star. There is no need for a focus-motor.

HTH!

Nicolàs

Edited September 2, 2023 by inFINNity Deck
Corrected link to part 2 of white papers

[Mandy D]

@Pankaj From what I can find, your camera will shoot video at a maximum of 30 fps, not 50. As Nicholas has said, the pixel size is 4.3 micron, which is quite large, so to get Jupiter across a decent number of pixels, you will need a long focal length. However, you also need to consider how the 1200D creates video files! Does it use 1:1 sensor pixel to 1080P video pixel translation, or is it using a larger area of the sensor, then down-converting it to 1080P resolution? I could not quickly find the answer on the internet, so what you should do is shoot some still frames and a few seconds of video, then compare how many pixels across the diameter Jupiter appears in video and still images. I know for fact that the Nikon D800 crops a large area from the full sensor to image the video, but resizes it to 1080P before saving. With the D800, it is possible to record the captured video directly to professional video equipment for broadcast quality video. For Jupiter, with the D800, I shoot only still frames at highest quality and stack them. I can grab, perhaps 100 frames per minute sustained.

IIRC, the D800 downscales by a factor of about 2.5:1 on resolution for video. I can get Jupiter across about 80 pixels on my sensor at native focal length shooting stills, or about 30 pixels from video. That is a huge difference.

[johnturley]

15 hours ago, inFINNity Deck said:

Hi Pankaj,

 

In short it comes down to that the focal ratio can be about 3 x the pixel-size of the camera. If I understand well the Canon 1200D has a pixel-size of 4.3 micron, so optimal sampling is done at a focal ratio of about 3 x 4.3 = f/12.9. Theoretically you could go as far as 3.7 x 4.3 = f/15.9, but seeing will limit this rule to about a factor 3 (at least at my location, not sure about yours in India). For your scope this means you could use a 2.5x or 3x Barlow. There is no need to guide, I have seen plenty examples of great planetary images using 'manual driven' dobsons. Please note that exposure times go up with larger Barlows.

 

If you want to use the Canon, I suggest you capture in highest resolution and maximum frame-rate. If that means you have to image separate files instead of AVI or other movie-format, you can use PIPP to create a SER-file from those separate images, which then can be processed in AutoStakkert!3.

 

If you are doing planetary imaging with a Canon 1200D (APS-C) sized sensor, I think that you will need to use eyepiece projection to get a decent sized image, a 2- 3x Barlow just won't give sufficient amplification. If the initial image size is too small, then you can't get sufficient decent alignment points in processing software such as AutoStakkert and Registax, a tiny image also makes initial focusing more difficult. 

When I used my Canon 6D (full frame sensor) with my 14in Newtonian, I needed to use eyepiece projection with a 12.5mm Plossl to get a decent sized image with Jupiter, and a 9.7mm for Saturn and Mars.

I now have a ZWO 462 Planetary Camera, which has 2.9 micron pixels, but unless viewing condition are particularly good, I prefer to image through my Esprit 150 (fl 1050mm). According to the formula, the optimal focal ratio should be 3 x 2.9 = f8.7, but to give a reasonable image size even with Jupiter, I need to use a least a 2.5x Powermate giving f17.5. 

One observer on this site produces excellent nice sized planetary images through his C11 (fl 2,800mm ) and ZWO 462 at f20 (2x Barlow) , or even f25 (2.5x Barlow).

John 

Edited September 3, 2023 by johnturley

[inFINNity Deck]

1 hour ago, johnturley said:

If you are doing planetary imaging with a Canon 1200D (APS-C) sized sensor, I think that you will need to use eyepiece projection to get a decent sized image, a 2- 3x Barlow just won't give sufficient amplification. If the initial image size is too small, then you can't get sufficient decent alignment points in processing software such as AutoStakkert and Registax.

When I used my Canon 6D (full frame sensor) with my 14in Newtonian, I needed to use eyepiece projection with a 12.5mm Plossl to get a decent sized image with Jupiter, and a 9.7mm for Saturn and Mars.

I now have a ZWO 462 Planetary Camera, which has 2.9 micron pixels, but unless viewing condition are particularly good, I prefer to image through my Esprit 150 (fl 1050mm). According to the formula, the optimal focal ratio the optimal focal ratio should be 3 x 2.9 = f8.7, but to give a reasonable image size even with Jupiter, I need to use a least a 2.5x Powermate giving f17.5. 

One observer on this site produces excellent nice sized planetary images through his C11 (fl 2,800mm ) and ZWO 462 at f20 (2x Barlow) , or even f25 (2.5x Barlow).

John 

Hi John,

Please note that there is a difference between "a decent sized image" and an image with maximum detail. The formula 3 x [pixel-size] (or 3.7 x [pixel-size]) gives the focal length at which the maximum detail is recorded. Going above this means that no additional detail is recorded while exposure times go up drastically (quadratic with the amount of oversampling, so going from a factor of 3 to a factor 6 increases exposure times by a factor of 4!). It is for that reason that I stick to the formula and create a decent size after processing by using a bicubic resize of 200%. I have been testing this with a ASI290MM and found no advantage detail-wise when compared to the ASI174MM that I normally use. The pixel-size of the ASI174MM is twice that of the ASI290MM (5.9 vs 2.9 micron), so I resized the ASI174MM images by 200% after stacking to make them the same size in below image (all imaged at f/20 with a C11 EdgeHD). The image at the far right is the same as the one at the centre, but with additional sharpening (bit too much to my liking, but it was to see what happens in the image analysis):

The bottom row images show the frequency spectra of the recordings made with ImageJ. I ran the three images through ImageJ to see if there were any differences in resolution. The three FFTJ transformations show that all images have approximately a 3-fold oversampling (if the rectangles are completely filled with data then there is no oversampling, if they are half filled then the oversampling is 2x, with a third it is 3x). For the two ASI174MM images this means that the originals have 1.5x oversampling, as they were scaled 200% in post-processing to make them the same size as the ASI290MM image (and a 200% scaling produces 2x oversampling).

So far I have had no issues with my alignment points at this lower scale, I usually use a combination of 24 and 48 pixel APs in AutoStakkert!3..

Nicolàs

[johnturley]

3 hours ago, inFINNity Deck said:

Hi John,

Please note that there is a difference between "a decent sized image" and an image with maximum detail. The formula 3 x [pixel-size] (or 3.7 x [pixel-size]) gives the focal length at which the maximum detail is recorded. Going above this means that no additional detail is recorded while exposure times go up drastically (quadratic with the amount of oversampling, so going from a factor of 3 to a factor 6 increases exposure times by a factor of 4!). It is for that reason that I stick to the formula and create a decent size after processing by using a bicubic resize of 200%. I have been testing this with a ASI290MM and found no advantage detail-wise when compared to the ASI174MM that I normally use. The pixel-size of the ASI174MM is twice that of the ASI290MM (5.9 vs 2.9 micron), so I resized the ASI174MM images by 200% after stacking to make them the same size in below image (all imaged at f/20 with a C11 EdgeHD). The image at the far right is the same as the one at the centre, but with additional sharpening (bit too much to my liking, but it was to see what happens in the image analysis):

 

 

Nicolàs

Nicolas

But you are using a C11 Edge HD (focal length 2,800mm), I think the situation would be somewhat different for someone using a much shorter focal length instrument, say 500 - 1,000mm, or a much larger sixed sensor than your ASI 174, or ASI290, as with a digital SLR.

John 

Edited September 3, 2023 by johnturley

[inFINNity Deck]

2 hours ago, johnturley said:

But you are using a C11 Edge HD (focal length 2,800mm), I think the situation would be somewhat different for someone using a much shorter focal length instrument, say 500 - 1,000mm, or a much larger sixed sensor than your ASI 174, or ASI290, as with a digital SLR.

John 

Hi John,

good point, sure there is a difference, so let's have a look at the maths.

Pankaj plans to use a 10" f/5 Newton with 2x Barlow and his Canon with 4.3 micron pixel-size. That combination yields a resolution of 4.3/(25.4 x 10 x 5 x 2) x 206.3 = 0.349"/pixel. Currently Jupiter is about 44.36" in apparent diameter, so that is 44.36 / 0.349 = 127 pixels on his camera. Now he should be imaging between f/12.9 and f/15.9, so should be using at least a 2.5x Barlow (f/12.5). Using that Barlow he would get a planetary diameter of 127 x (2.5/2) = 159 pixels (3 x Barlow would make this even 190px). In my set-up this would become about 204 pixels, so indeed significantly larger (about 28% more than with with the 2.5x Barlow), but not a whole lot, and even insignificant if he would use a 3x Barlow. The diameter of Saturn with rings is approximately equal to Jupiter at the moment (44.14" vs 44.36"), so that planet would give the same results. The planet itself (i.e. the globe of Saturn) is of course quite a bit smaller, that would become 67 pixels would Pankaj use a 2.5 Barlow (81px when using a 3x Barlow).

Above images of Mars were taken on 26 December 2022 while it was only 15.35" in apparent diameter, so a third of current Jupiter and Saturn and thus only about 75 pixels in my 3 x [pixel-size] set-up, so approximately the same size as the Jupiter that Pankaj can image with his set-up.

Nicolàs

[johnturley]

7 hours ago, inFINNity Deck said:

Hi John,

good point, sure there is a difference, so let's have a look at the maths.

Pankaj plans to use a 10" f/5 Newton with 2x Barlow and his Canon with 4.3 micron pixel-size. That combination yields a resolution of 4.3/(25.4 x 10 x 5 x 2) x 206.3 = 0.349"/pixel. Currently Jupiter is about 44.36" in apparent diameter, so that is 44.36 / 0.349 = 127 pixels on his camera. Now he should be imaging between f/12.9 and f/15.9, so should be using at least a 2.5x Barlow (f/12.5). Using that Barlow he would get a planetary diameter of 127 x (2.5/2) = 159 pixels (3 x Barlow would make this even 190px). In my set-up this would become about 204 pixels, so indeed significantly larger (about 28% more than with with the 2.5x Barlow), but not a whole lot, and even insignificant if he would use a 3x Barlow. The diameter of Saturn with rings is approximately equal to Jupiter at the moment (44.14" vs 44.36"), so that planet would give the same results. The planet itself (i.e. the globe of Saturn) is of course quite a bit smaller, that would become 67 pixels would Pankaj use a 2.5 Barlow (81px when using a 3x Barlow).

Above images of Mars were taken on 26 December 2022 while it was only 15.35" in apparent diameter, so a third of current Jupiter and Saturn and thus only about 75 pixels in my 3 x [pixel-size] set-up, so approximately the same size as the Jupiter that Pankaj can image with his set-up.

Nicolàs

Nicolàs

You make no mention of sensor size or capture area, I don’t know by how much, if at all, you can crop the capture area with the Canon 1200D, but it will be almost certainly less than with a dedicated planetary camera. So if Pankaj uses his 10" f/5 Newton with 2x Barlow and his Canon 1200D (Aps-C sized sensor 24x18mm), using no more than a 2-3x Barlow for amplification, then I think that he will be disappointed with the resultant small image size.

My first attempts at imaging with my ZWO ASI 462 Planetary Camera (which has a sensor size of just 5.6 x 3.1mm) through my Esprit 150 weren’t that great, as I didn’t appreciate that you need to crop the capture area to get an image that appears to be of decent size.

My first attached image taken in August 2021, shows the result of an uncropped image at the native f7, which isn’t actually far from what is supposed to be the optimum of 3x the pixel size of 2,9 um. Although the size of this image can be increased using post processing software, I found that if I tried to do this by more than 2x, the results weren’t great.

The second attached image was taken with the same setup, taken in October 2022, but using a 2.5x Powermate, giving f17.5 (nearly double what is supposed to be the optimum), and cropping the capture area, giving a much larger apparent image of reasonable size. I think that you will agree that the second image, which shows the GRS, is much better showing far more detail.

The third attached image taken in August 2020 shows what I achieved using eyepiece projection (I think that I used a 12.5mm Plossl) with a Canon 6D full frame digital SLR,  if I had just used a 2-3x Barlow, the image size would have been much smaller. At the time Jupiter was quite low down, and it was more difficult to focus through the camera viewfinder. 

John 

Edited September 3, 2023 by johnturley

[inFINNity Deck]

Hi John,

thanks for those example images. I do not mention chip-size simply because it is irrelevant. If you do not want that black space around the object, simply crop it in the post-processing. None of the planetary images I show on my website are shown at the actual image size they were imaged at, most of them have a larger background than original, while almost all have been resize by that 200% I mentioned before in order to make them a decent size for viewing.

Going back to your images: number three was taken without an ADC (or with a poor aligned camera to eye-piece set-up), so no point discussing that one. The first image was not properly exposed. The histogram looks fine, but the central part of the planet seems overexposed (or flattened in post-processing), so again no use discussing that one.

The second image is fine. You wrote that it was taken at f/17.5, where the optimum would be between f/12.9 and f/15.9, so we may expect it to be oversampled if we analyse it. So I ran it through ImageJ to get the frequency spectrum of it:

If it were properly sampled the result would have filled most of the image, now it shows that the original image was oversampled by at least a factor 3. That this is more than based on pixel-size and focal length alone is due to seeing (I explain that in my second article). This means that if we resize the original image to 33% and then resize it back to original we should see no significant loss in detail. So, I took your image, resized it to 33%, then resized it by 300%. I then took another copy, resized it by 50%, followed by a 200% resize:

The one at the left is the 33% resize. The process has made the smallest details a bit square, but there is hardly any significant loss of detail. But as I did not like the square details, I did the second resize with 50%. I leave it up to you to decide which of the two remaining images is your original and which is the resized one.

The point I try to make is that, when using an optimal focal ratio, the exposure times go down significantly. Had the image been made at about f/9, the exposure time would have been 4 times as low, resulting in a higher frame-rate and thus more data in the same time-span (and thus a better signal-to-noise ratio had the same percentage of frames been stacked).

Nicolàs

PS: the file-name reveals the answer

Edited September 4, 2023 by inFINNity Deck

[johnturley]

8 hours ago, inFINNity Deck said:

Hi John,

 I do not mention chip-size simply because it is irrelevant. If you do not want that black space around the object, simply crop it in the post-processing. None of the planetary images I show on my website are shown at the actual image size they were imaged at, most of them have a larger background than original, while almost all have been resize by that 200% I mentioned before in order to make them a decent size for viewing.

The point I try to make is that, when using an optimal focal ratio, the exposure times go down significantly. Had the image been made at about f/9, the exposure time would have been 4 times as low, resulting in a higher frame-rate and thus more data in the same time-span (and thus a better signal-to-noise ratio had the same percentage of frames been stacked).

Nicolàs

 

You state that the chip size is irrelevant, but the general consensus on this site appears to be that for planetary imaging you need a camera with a small sized sensor, and that digital SLR’s are not ideal for planetary imaging due to their relatively large sensor size. If this were not the case, then why would some observers have 2 or more cameras one with a small sensor for planets, and one with a larger sensor for deep sky objects, if the camera with the larger sensor would suffice just as well for both.

Having said that, I accept that for a given optical arrangement, the size of the image on the sensor will be exactly the same regardless of the size of the sensor, or the degree of cropping used. It appears to be that the software used for image viewing just displays the images taken with a small sensor and/or cropped as being larger, which makes them more aesthetically pleasing, and easier to process. I would love to see a large detailed planetary image taken with a digital SLR, using no more than a 2-3x Barlow for amplification, which you and some others say is possible.

Some observers are also of the opinion that around 2x oversampling gives better results than the theoretical optimum of around 3x the pixel size. I suppose it’s a bit similar to saying that with for example a 6-12in aperture telescope a magnification of about 50-100x is capable of revealing all the planetary detail that is there, but most observers find under good conditions, using a magnification of 200-300x more aesthetically pleasing.

I will however try doing some imaging closer to what should be the optimal focal ratio, using additional cropping or the drizzle function in Autostakkert to increase the image size to see whether it does give better results

John  

Edited September 4, 2023 by johnturley

[powerlord]

On 03/09/2023 at 09:48, johnturley said:

If you are doing planetary imaging with a Canon 1200D (APS-C) sized sensor, I think that you will need to use eyepiece projection to get a decent sized image, a 2- 3x Barlow just won't give sufficient amplification. If the initial image size is too small, then you can't get sufficient decent alignment points in processing software such as AutoStakkert and Registax, a tiny image also makes initial focusing more difficult. 

When I used my Canon 6D (full frame sensor) with my 14in Newtonian, I needed to use eyepiece projection with a 12.5mm Plossl to get a decent sized image with Jupiter, and a 9.7mm for Saturn and Mars.

I now have a ZWO 462 Planetary Camera, which has 2.9 micron pixels, but unless viewing condition are particularly good, I prefer to image through my Esprit 150 (fl 1050mm). According to the formula, the optimal focal ratio should be 3 x 2.9 = f8.7, but to give a reasonable image size even with Jupiter, I need to use a least a 2.5x Powermate giving f17.5. 

One observer on this site produces excellent nice sized planetary images through his C11 (fl 2,800mm ) and ZWO 462 at f20 (2x Barlow) , or even f25 (2.5x Barlow).

John 

I'd consider using a mobile phone on the eyepiece instead of the 1200d frankly - with the phone shooting the highest frame rate it can - some with do 240fps 1080p.

[inFINNity Deck]

16 minutes ago, johnturley said:

You state that the chip size is irrelevant, but the general consensus on this site appears to be that for planetary imaging you need a camera with a small sized sensor, and that digital SLR’s are not ideal for planetary imaging due to their relatively large sensor size. If this were not the case, then why would some observers have 2 or more cameras one with a small sensor for planets, and one with a larger sensor for deep sky objects, if the camera with the larger sensor would suffice just as well for both.

Having said that, I accept that for a given optical arrangement, the size of the image on the sensor will be exactly the same regardless of the size of the sensor, or the degree of cropping used. It appears to be that the software used for image viewing just displays the images taken with a small sensor and/or cropped as being larger, which makes them more aesthetically pleasing, and easier to process. I would love to see a large detailed planetary image taken with a digital SLR, using no more than a 2-3x Barlow for amplification, which you and some others say is possible.

Some observers are also of the opinion that around 2x oversampling gives better results than the theoretical optimum of around 3x the pixel size. I suppose it’s a bit similar to saying that with for example a 6-12in aperture telescope a magnification of about 50-100x is capable of revealing all the planetary detail that is there, but most observers find under good conditions, using a magnification of 200-300x more aesthetically pleasing.

I will however try doing some imaging closer to what should be the optimal focal ratio, using additional cropping or the drizzle function in Autostakkert to increase the image size to see whether it does give better results

John  

Hi John,

you are right that smaller size is better, simply because the frame-rate will be (much) higher, but otherwise it is not much of an issue to use a larger size sensor (well, that is if we do not mind consuming a lot of disk-space 😉).

Indeed quite a few imager do use 2x oversampling for the same reasons you mentioned.

Looking forward to your results closer to the optimal focal ratio!

clear skies!

Nicolàs

[inFINNity Deck]

12 minutes ago, powerlord said:

I'd consider using a mobile phone on the eyepiece instead of the 1200d frankly - with the phone shooting the highest frame rate it can - some with do 240fps 1080p.

I have seen quite decent images using mobile phones, their cameras are getting better by the year. looking forward to those results as well!

Nicolàs

[powerlord]

On 02/09/2023 at 09:36, Pankaj said:

Hello Everyone. Wanted to learn how to image and post process planets. Is there a complete tutorial somewhere from which I can learn. I have the following equipment which I wanted to use in the initial phase. Will try my hand on unguided imaging first. It will be nice if someone can suggest how to image, stack and process the pictures. Which software to use etc?

Mount - NEQ6 Pro

Scope - 10" Newt F5 with a 2x Barlow

Camera - Canon 1200D Unmodded

Basic lucky imaging process:

- take video

- pass video through PIPP (optional, but good at stablising, getting in right format and normalising historgram)

- stick output into autostakker. this will actually to the 'stack' - basically you choose the best % to stack (it shows a graph so just choose something to get you only the best - usually it's about 5% for me)

- stick that output tiff into registax - and do sharpening (you'll be amazed how much it can get out)

- final tweeks in the photo editor of your choice.

absolute KEY to the process of 'lucky imaging' is to take MASSIVE numbers of images so that you get 'lucky' with some. the software then stacks up the lucky ones. lucky == you took it and froze the atmosphere just when some part of it was lovely and clear.

So, you need to maximise your luck by buying as many lottery tickets (frames) as possible.

The key thing about tiny wee planetary sensor cameras are that they can take 100s of frames per second in RAW format. So no compression - what you see is what gets recorded, 100s of times every second. Typically you capture maybe 10,000 frames. (of course its worth saying - they do not in fact do this.. not like a regular camera - you need to connect them to a computer that actually takes the pics- and that needs to be quick enough and have a quick enough SSD to actually store those 100s frames per second).

This above anything else is why DSLRs are not really up to it.

Now that is not to say you cannot get good results with something like the moon. Your actual exposure will still be short enough to freeze the atmosphere. It's just that in order to really have much 'luck' you need lots of images. With the moon covering the whole DSLR frame you might be some improvements with say 100 frames or so. But with planets, they are tiny. Even on wee astro camera you are choosing a small section to actually capture from - maybe 500x500 pixels or so to maximise frame rate. So the effects of the atmosphere are massive. you need those 10000s of frames to get 'lucky' basically.

So I'd say, give the moon a go first, and play around with raw images - forget video from the DSLR. If you get a taste for it, next step would be maybe a cheaper astro camera - one that is a fancy webcam basically like a cheap SVBONY one for 40 quid. Or, keep your eyes open for an ZWO 120 or 224.

stu

Edited September 4, 2023 by powerlord

[Pankaj]

On 04/09/2023 at 21:35, powerlord said:

Basic lucky imaging process:

- take video

- pass video through PIPP (optional, but good at stablising, getting in right format and normalising historgram)

- stick output into autostakker. this will actually to the 'stack' - basically you choose the best % to stack (it shows a graph so just choose something to get you only the best - usually it's about 5% for me)

- stick that output tiff into registax - and do sharpening (you'll be amazed how much it can get out)

- final tweeks in the photo editor of your choice.

absolute KEY to the process of 'lucky imaging' is to take MASSIVE numbers of images so that you get 'lucky' with some. the software then stacks up the lucky ones. lucky == you took it and froze the atmosphere just when some part of it was lovely and clear.

So, you need to maximise your luck by buying as many lottery tickets (frames) as possible.

The key thing about tiny wee planetary sensor cameras are that they can take 100s of frames per second in RAW format. So no compression - what you see is what gets recorded, 100s of times every second. Typically you capture maybe 10,000 frames. (of course its worth saying - they do not in fact do this.. not like a regular camera - you need to connect them to a computer that actually takes the pics- and that needs to be quick enough and have a quick enough SSD to actually store those 100s frames per second).

This above anything else is why DSLRs are not really up to it.

Now that is not to say you cannot get good results with something like the moon. Your actual exposure will still be short enough to freeze the atmosphere. It's just that in order to really have much 'luck' you need lots of images. With the moon covering the whole DSLR frame you might be some improvements with say 100 frames or so. But with planets, they are tiny. Even on wee astro camera you are choosing a small section to actually capture from - maybe 500x500 pixels or so to maximise frame rate. So the effects of the atmosphere are massive. you need those 10000s of frames to get 'lucky' basically.

So I'd say, give the moon a go first, and play around with raw images - forget video from the DSLR. If you get a taste for it, next step would be maybe a cheaper astro camera - one that is a fancy webcam basically like a cheap SVBONY one for 40 quid. Or, keep your eyes open for an ZWO 120 or 224.

stu

Thanks. This is crystal clear now. Just one query - i have a Datyson T7S camera that use for guiding when shooting DSOs. Its pretty decent at guiding my NEQ6. I have read at many places that this camera is equivalent to ASI120MM. What if I use this camera for imaging the planets too ? Would I have to take videos with this camera or stills ?

 

[powerlord]

yes that would work great. and you'd take video.