Beginning planetary imaging with a 150mm Newtonian (F5) - which barlow or powermate for planetary?

[johnturley]

19 hours ago, Altair8389 said:

Thank you John.

Thats very informative. At the moment, I do not envisage spending big on a heavy mount which can support a C14 telescope which is also quite expensive and I do not have the room in my home at present for such a large scope (too heavy) and big.

But maybe in the future (I would perhaps need a helper to setup my C14)...

 

Magnus

You don't need a long focus SCT to produce excellent planetary images, some observers have posted excellent images taken with 150 mm Newtonians, 127 mm MAC's, and Neil Phillips in particular with a 250 mm f5 Newtonian.

It's just that the former allow you to get closer to the supposed optimal focal ratio for some planetary cameras, based upon 3x the pixel size. 

John 

Edited August 24, 2022 by johnturley

[johnturley]

On 23/08/2022 at 12:33, CraigT82 said:

Gimp is completely free John 👍🏼

Hi Graig

I downloaded GIMP, and gave it a try, but I didn't have much success with it.

I'm probably missing something obvious, but I tried altering the image size as you suggested in GIMP, from about 1,920 to 4,000 (which incidentally is the same as what you can do in Registax), but after saving the image back into a folder on my laptop, the saved image ended up the same size as it was before, which is the same as what happens in Registax.

Moreover in GIMP, unlike Registax, the image does not save as a JPEG image, but as a GIMP image which then has to load GIMP in order to view, and I couldn't find a way of saving as a JPEG image (see for example attached image of Jupiter. showing Io Shadow Transit, and still the same size after enlarging it about 2x in GIMP)

Jupiter B 29.08.21 with Io Shadow Transit..xcf

Edited August 25, 2022 by johnturley

[vlaiv]

5 minutes ago, johnturley said:

, the saved image ended up the same size as it was before

When you say this, what do you actually mean?

[johnturley]

1 minute ago, vlaiv said:

When you say this, what do you actually mean?

The same small physical on the computer screen, as with the above image of Jupiter, showing a shadow transit of Jupiter. 

[vlaiv]

1 minute ago, johnturley said:

The same small physical on the computer screen, as with the above image of Jupiter, showing a shadow transit of Jupiter. 

Ok, so your image size is 4000x2264 px

That is way too big image to be shown on 1920x1080 FullHD screen - and will always be resized to fit the screen.

First thing you need to do - is select area around Jupiter and crop image so that only sensible size of pixels around Jupiter is contained in the image.

Select crop tool:

Make selection around Jupiter with it:

Say around 800x600 px.

Then press enter to perform actual crop.

Next, to save it as jpg - choose Export as option in File menu:

Now you can save it as jpeg.

Given that it is now smaller than your computer screen - it will no longer be scaled down and it will look like this:

[johnturley]

14 minutes ago, vlaiv said:

Ok, so your image size is 4000x2264 px

That is way too big image to be shown on 1920x1080 FullHD screen - and will always be resized to fit the screen.

First thing you need to do - is select area around Jupiter and crop image so that only sensible size of pixels around Jupiter is contained in the image.

Select crop tool:

Make selection around Jupiter with it:

Say around 800x600 px.

Then press enter to perform actual crop.

Next, to save it as jpg - choose Export as option in File menu:

Now you can save it as jpeg.

Given that it is now smaller than your computer screen - it will no longer be scaled down and it will look like this:

Will give that a try, I tried it in Registax, but it didn't make any difference to the size of the saved image.

John 

[neil phillips]

On 24/08/2022 at 12:59, johnturley said:

You don't need a long focus SCT to produce excellent planetary images, some observers have posted excellent images taken with 150 mm Newtonians, 127 mm MAC's, and Neil Phillips in particular with a 250 mm f5 Newtonian.

It's just that the former allow you to get closer to the supposed optimal focal ratio for some planetary cameras, based upon 3x the pixel size. 

John 

Just for clarity its actually F6.3 Not F5 John And thats native not Barlowed

Edited August 25, 2022 by neil phillips

[johnturley]

12 minutes ago, johnturley said:

Will give that a try, I tried it in Registax, but it didn't make any difference to the size of the saved image.

John 

I've just tried it now, and it appears to work, it actually saves as a PNG rather than a JPEG file, I didn't realise that you have to do 'Export' rather than 'Save as', similar to as you do in Lightroom.

Maybe you can do something similar in Registax, rather than having to load GIMP, will look into this.

I've been asking the question about how to enlarge images in various threads for about the last 12 months, and previously nobody has been able to answer this question.

John 

[johnturley]

5 hours ago, neil phillips said:

Just for clarity its actually F6.3 Not F5 John And thats native not Barlowed

Sorry I forgot that its f6.3, I used to have a Fullerscopes f6.3 10in Reflector many years ago, which was good on planets.

If you are using that scope un-barlowed , then the focal length will be the native 1,575 mm, which will produce quite small images with approx 1/3 sensor sized planetary cameras, such as the ZWO ASI 224 and 462, so unless the camera you are using produces much larger images, then I assume that you must be  increasing the image size around 3 - 4x with software like GIMP, to produce the images of Jupiter that you post on this site.

The attached image shows the size of the Jupiter image obtained with my ZWO 462 planetary camera, through my 14in Newtonian un-barlowed, which has a native focal length of about 1,800 mm. 

 

John 

Edited August 25, 2022 by johnturley

[neil phillips]

3 hours ago, johnturley said:

Sorry I forgot that its f6.3, I used to have a Fullerscopes f6.3 10in Reflector many years ago, which was good on planets.

If you are using that scope un-barlowed , then the focal length will be the native 1,575 mm, which will produce quite small images with approx 1/3 sensor sized planetary cameras, such as the ZWO ASI 224 and 462, so unless the camera you are using produces much larger images, then I assume that you must be  increasing the image size around 3 - 4x with software like GIMP, to produce the images of Jupiter that you post on this site.

The attached image shows the size of the Jupiter image obtained with my ZWO 462 planetary camera, through my 14in Newtonian un-barlowed, which has a native focal length of about 1,800 mm. 

 

John 

Again no I was just pointing out the native FL of the scope. Not being F5

 Ok Here's the deal. I never resize my Jupiter images the way your considering. I don't have to.

First I use a Barlow lens attached to the ADC. I often do a Registax 1.5x drizzle that will increase the size a third. ( because i like the way it effects registax wavelets is one reason)

Then I downsize by varying degrees. Most often a 25% reduction. sometimes 30% Putting the image back much closer to the original pre drizzle size. I am slightly perplexed on your interest on resizing images. As Vlaiv has correctly pointed out. If your correctly sampling, with a semi planetary scope like a 10" F6.3 Newtonian. The image size will be healthy as is.

Especially as ive pointed out I do a 1.5 x drizzle that I can downsize to taste. With the ZWO ADC  in the train I am often oversampled. Because of the extra amplification that occurs with the extra distance between the Barlow and camera sensor.. Not by choice I might add. But because of limitations of barlow powers that I own. 

(Also something perhaps that is throwing you off when you try to understand my image size) So that should hopefully clear up Your interest in resizing images.

Being correctly sampled with the right instrument.  I personally would aim for slightly oversampled. As opposed to slightly under sampled) If it can not be achieved exactly

But that's a choice you can make through experimenting. I said it before. Try correctly sampling with your 14" Newtonian. And your image scale should be fine. If you feel you need extra ( I personally like the way 1.5 x drizzle Effects my sharpening routines ) Perhaps that's something you also could try. Though drizzle is primarily  used for under sampled images. And will have no other benefit than the one I suggested earlier. Other than perhaps be easier to see two close points. With my somewhat aging eyes while processing before downsizing. 

Good luck

 

Edited August 25, 2022 by neil phillips

[johnturley]

On 25/08/2022 at 20:18, neil phillips said:

Again no I was just pointing out the native FL of the scope. Not being F5

 Ok Here's the deal. I never resize my Jupiter images the way your considering. I don't have to.

First I use a Barlow lens attached to the ADC. I often do a Registax 1.5x drizzle that will increase the size a third. ( because i like the way it effects registax wavelets is one reason)

Then I downsize by varying degrees. Most often a 25% reduction. sometimes 30% Putting the image back much closer to the original pre drizzle size. I am slightly perplexed on your interest on resizing images. As Vlaiv has correctly pointed out. If your correctly sampling, with a semi planetary scope like a 10" F6.3 Newtonian. The image size will be healthy as is.

Especially as ive pointed out I do a 1.5 x drizzle that I can downsize to taste. With the ZWO ADC  in the train I am often oversampled. Because of the extra amplification that occurs with the extra distance between the Barlow and camera sensor.. Not by choice I might add. But because of limitations of barlow powers that I own. 

(Also something perhaps that is throwing you off when you try to understand my image size) So that should hopefully clear up Your interest in resizing images.

Being correctly sampled with the right instrument.  I personally would aim for slightly oversampled. As opposed to slightly under sampled) If it can not be achieved exactly

But that's a choice you can make through experimenting. I said it before. Try correctly sampling with your 14" Newtonian. And your image scale should be fine. If you feel you need extra ( I personally like the way 1.5 x drizzle Effects my sharpening routines ) Perhaps that's something you also could try. Though drizzle is primarily  used for under sampled images. And will have no other benefit than the one I suggested earlier. Other than perhaps be easier to see two close points. With my somewhat aging eyes while processing before downsizing. 

Good luck

 

Neil

Thanks for your detailed and informative reply.

The attached images of Saturn and Jupiter (which I have also posted on the 'What did you see last night thread'), show the size I get with the Esprit 150 and a 2.5 x Powermate, (which I acquired this week) which gives an effective focal length of 2,600 mm, not too bad maybe, but still a bit on the small side. I originally tried imaging with a 5x Powermate, but it didn't give very good results (maybe because the dim image reduced the frame rate too much), although it might work ok under very good atmospheric conditions, and might be required for the tiny disc of Mars.  Obviously with the same 'barlow' 'arrangement, with an effective focal length of  4,500 I will get larger sized images. I did try some imaging with the 14in last week, but I can't say the results were dramatically different, and as I've menti0ned preciously, it makes it more difficult to balance the telescope. 

I've tried the 1.5x 'drizzle function in Registax a few times, but it just didn't seem to work, more often than not the image just 'disappeared' during the stacking process in Registax (don't know why). I've also tried enlarging the image in GIMP as suggested by Vlaiv, which does work, but the results are not always that great, I think that you are limited in practice to a 1.5 to 2x amplification.

I do have a ZWO ADC, which I could put in the light path with the Esprit (but there would be insufficient in travel with the Newtonian), I do find that the ADC (to which I have attached a Baader Neodymium filter) helps a bit with visual views through the Newtonian, but not much gain with the refractor, but then from what you've said it has a similar effect to using a higher amplification barlow or Powermate. 

I'm a bit confused at what you mean by 'Being correctly sampled with the right instrument', I've done some captures by reducing the native capture area of the ASI 462 from native 1936 x 1096 to around 800 x 600, this does give a much larger image on the laptop when imaging, I gather also allows a faster frame rate, and takes up less computer memory, but after processing the image size is exactly the same. 

Maybe the ASI 462 was not the best camera for me for planetary imaging, but FLO recommended this model over the cheaper ASI 224 for planetary imaging, the latter has a slightly smaller sensor size of 1/3 as opposed to 1/2.8 (so not much difference), but has at maximum 30 fps at it's maximum resolution of 1280 x 960, as opposed to 136 fps at 1936 x 1096 of the 462, hence I thought that I was getting a better camera.

I've also tried Autostakkert, which some recommend over Registax, but what not impressed with my first results, also pre-processing in PIPP (which I needed when using my Canon 6D for planetary imaging), but couldn't see any improvement, and its slows down aligning and stacking in Registax. Some also recommend imaging in RAW rather than RGB 24, as it allows a faster frame rate, but then I gather you then need PIPP or Autostakkert to Debayer the monochrome images to get them back into colour.

Edited August 27, 2022 by johnturley

[vlaiv]

16 minutes ago, johnturley said:

The attached images of Saturn and Jupiter (which I have also posted on the 'What did you see last night thread'), show the size I get with the Esprit 150 and a 2.5 x Powermate, (which I acquired this week) which gives an effective focal length of 2,600 mm, not too bad maybe, but still a bit on the small side.

Your planets are already larger then they should be.

I know this might sound strange, but just hear me out for a second.

Maximum planet size that you can record - that is not over sampled - meaning "just enlarged without any detail" (which is what you also get when enlarging in software) - is governed by aperture size.

There is only so much detail that you can get with given aperture size - that is called resolving capability of the telescope. It is down to laws of physics and does not depend on quality of the telescope.

You can calculate this size for any given aperture and also calculate needed F/ratio for given pixel size.

ASI462 has 2.9um pixel size. Optimum F/ratio for planetary imaging is x4 this number at F/11.6. You are already at F/7 with your esprit, so you need only x1.65 barlow (not x2.5 or higher. Take x1.5 or x2 barlow element and dial in distance to sensor to get x1.65 magnification - by the way, this only works with barlow, not with telecentric like powermate).

At F/11.6, 150mm of aperture will result in 1740mm of focal length. With 2.9um pixel size - that is 0.3438"/px.

Given that Jupiter is now 48" in diameter - that results in 139px image of Jupiter's disk. That is maximum that you can get with full detail.

29 minutes ago, johnturley said:

I'm a bit confused at what you mean by 'Being correctly sampled with the right instrument', I've done some captures by reducing the native capture area of the ASI 462 from native 1936 x 1096 to around 800 x 600, this does give a much larger image on the laptop when imaging, I gather allows a faster frame rate, and takes up less computer memory, but after processing the image size is exactly the same. 

Maybe the ASI 462 was not the best camera for me for planetary imaging, but FLO recommended this model over the cheaper ASI 224 for planetary imaging, the latter has a slightly smaller sensor size of 1/3 as opposed to 1/2.8 (so not much difference), but has at maximum 30 fps at it's maximum resolution of 1280 x 960, as opposed to 136 fps at 1936 x 1096 of the 462, hence I thought that I was getting a better camera.

With planetary camera you need to consider only a few things:

- QE of sensor

- Read noise level

- how fast the read out is.

Maximum frame rate of ASI224 is over 300fps (640×480 299.4fps, 320×240 577.9fps in 8bit mode) and it is still one of the best planetary cameras.

ASI462 is not bad either. Both can produce excellent results. Only difference is in pixel size and F/ratio needed. ASI224 needs F/15 while ASI462 needs F/11.6

 

[johnturley]

 

1 hour ago, vlaiv said:

Your planets are already larger then they should be.

I know this might sound strange, but just hear me out for a second.

Maximum planet size that you can record - that is not over sampled - meaning "just enlarged without any detail" (which is what you also get when enlarging in software) - is governed by aperture size.

There is only so much detail that you can get with given aperture size - that is called resolving capability of the telescope. It is down to laws of physics and does not depend on quality of the telescope.

You can calculate this size for any given aperture and also calculate needed F/ratio for given pixel size.

ASI462 has 2.9um pixel size. Optimum F/ratio for planetary imaging is x4 this number at F/11.6. You are already at F/7 with your esprit, so you need only x1.65 barlow (not x2.5 or higher. Take x1.5 or x2 barlow element and dial in distance to sensor to get x1.65 magnification - by the way, this only works with barlow, not with telecentric like powermate).

At F/11.6, 150mm of aperture will result in 1740mm of focal length. With 2.9um pixel size - that is 0.3438"/px.

Given that Jupiter is now 48" in diameter - that results in 139px image of Jupiter's disk. That is maximum that you can get with full detail.

With planetary camera you need to consider only a few things:

- QE of sensor

- Read noise level

- how fast the read out is.

Maximum frame rate of ASI224 is over 300fps (640×480 299.4fps, 320×240 577.9fps in 8bit mode) and it is still one of the best planetary cameras.

ASI462 is not bad either. Both can produce excellent results. Only difference is in pixel size and F/ratio needed. ASI224 needs F/15 while ASI462 needs F/11.6

 

TOTALLY CONFUSED, the images are way smaller than those most people post !

At f11.6 (the supposed optimum for the ASI 462) the images would have been even smaller !

Looks like I would have been better off with the ASI 224 (maybe I should get one of these), but FLO recommended the 462 over the 224, maybe I was given the wrong advice.

'There is only so much detail that you can get with given aperture size - that is called resolving capability of the telescope. It is down to laws of physics and does not depend on quality of the telescope'

Try telling that to the owner of a 3-4 in TAK !

John 

John 

Edited August 27, 2022 by johnturley

[neil phillips]

12 minutes ago, johnturley said:

Neil

Thanks for your detailed and informative reply.

The attached images of Saturn and Jupiter (which I have also posted on the 'What did you see last night thread'), show the size I get with the Esprit 150 and a 2.5 x Powermate, (which I acquired this week) which gives an effective focal length of 2,600 mm, not too bad maybe, but still a bit on the small side. I originally tried imaging with a 5x Powermate, but it didn't give very good results (maybe because the dim image reduced the frame rate too much), although it might work ok under very good atmospheric conditions, and might be required for the tiny disc of Mars.  Obviously with the same 'barlow' 'arrangement, with an effective focal length of  4,500 I will get larger sized images. I did try some imaging with the 14in last week, but I can't say the results were dramatically different, and as I've menti0ned preciously, it makes it more difficult to balance the telescope. 

I've tried the 1.5x 'drizzle function in Registax a few times, but it just didn't seem to work, more often than not the image just 'disappeared' during the stacking process in Registax. I've also tried enlarging the image in GIMP as suggested by Vlaiv, which does work, but the results are not always that great, I think that you are limited in practice to a 1.5 to 2x amplification.

I do have a ZWO ADC, which I could pit in the light path with the Esprit (but there would be insufficient in travel with the Newtonian), I do find that the ADC (to which I have attached a Baader Neodymium filter) helps a bit with visual views through the Newtonian, but not much gain with the refractor, but then from what you've said it has a similar effect to using a higher amplification barlow or Powermate. 

I'm a bit confused at what you mean by 'Being correctly sampled with the right instrument', I've done some captures by reducing the native capture area of the ASI 462 from native 1936 x 1096 to around 800 x 600, this does give a much larger image on the laptop when imaging, I gather allows a faster frame rate, and takes up less computer memory, but after processing the image size is exactly the same. 

Maybe the ASI 462 was not the best camera for me for planetary imaging, but FLO recommended this model over the cheaper ASI 224 for planetary imaging, the latter has a slightly smaller sensor size of 1/3 as opposed to 1/2.8 (so not much difference), but has at maximum 30 fps at it's maximum resolution of 1280 x 960, as opposed to 136 fps at 1936 x 1096 of the 462, hence I thought that I was getting a better camera.

I've also tried Autostakkert, which some recommend over Registax, but what not impressed with my first results, also pre-processing in PIPP (which I needed when using my Canon 6D for planetary imaging), but couldn't see any improvement. Some also recommend imaging in RAW rather than RGB 24, as it allows a faster frame rate, but then I gather you need PIPP or Autostakkert to Debayer the monochrome images to get them back into colour.

 ---I'm a bit confused at what you mean by 'Being correctly sampled with the right instrument---

I meant if you want quality like what i am producing your likely not going to get it with the Esprit. I cant see why the 14" Newtonian wont produce good results. Its around F5 if I remember ?

Correctly sample the 14 " it should be fine. You wont get quality trying to upscale small images. The size should be coming from focal length. Not gimp

This from a 12" SW 300P F5

 

 

[CraigT82]

17 minutes ago, johnturley said:

Looks like I would have been better off with the ASI 224 (maybe I should get one of these), but FLO recommended the 462 over the 224, maybe I was given the wrong advice.

Their advice was sound…Although the 224 has larger pixels and thus takes extra focal length, the image of the planet will occupy the same number of pixels on the chip as the smaller sensor (if both are sampled correctly) and so when that image is viewed at 100% on a screen the image will be the same size as the image from the smaller pixel sensor shot with less focal length. 

[vlaiv]

16 minutes ago, johnturley said:

Try telling that to the owner of a 3-4 in TAK !

Have you seen any Jupiter images produced with TAK that is better than say mass produced 8" newtonian?

17 minutes ago, johnturley said:

TOTALLY CONFUSED, the images are way smaller than those most people post !

But they are not.

You are confusing (still) two things:

FOV and scaled image and 100% zoom 1:1 pixel image.

This is the size of your Jupiter:

It is the same size of Jupiter that you will get if you open image you posted above in new window (right click, open in new window) and then - set zoom to 100% instead of image being scaled to display size.

Whenever you have image that is larger in pixels than display device - it will be scaled down to fit the screen and objects in the image will look smaller.

You don't need that much FOV around planetary images. That is why people use ROI of say 640x480px. It is more than enough for even 14" telescope to fit Jupiter.

Look at image posted by Neil above - it is only ~450x450 px - yet Jupiter is large in it.

Your image is full format 1936x1096. Compared to image itself, Jupiter that should be something like 136px or so - will be tiny - it will be less than 10% in width and height.

On the other hand - if you put image that is 400x400 - it will occupy 1/3 in height and width.

You should really try to understand:

- FOV vs pixel count and pixel size

- Scaling - especially "fit to screen" and 100% zoom level

[johnturley]

1 hour ago, vlaiv said:

Have you seen any Jupiter images produced with TAK that is better than say mass produced 8" newtonian?

But they are not.

You are confusing (still) two things:

FOV and scaled image and 100% zoom 1:1 pixel image.

This is the size of your Jupiter:

It is the same size of Jupiter that you will get if you open image you posted above in new window (right click, open in new window) and then - set zoom to 100% instead of image being scaled to display size.

Whenever you have image that is larger in pixels than display device - it will be scaled down to fit the screen and objects in the image will look smaller.

You don't need that much FOV around planetary images. That is why people use ROI of say 640x480px. It is more than enough for even 14" telescope to fit Jupiter.

Look at image posted by Neil above - it is only ~450x450 px - yet Jupiter is large in it.

Your image is full format 1936x1096. Compared to image itself, Jupiter that should be something like 136px or so - will be tiny - it will be less than 10% in width and height.

On the other hand - if you put image that is 400x400 - it will occupy 1/3 in height and width.

You should really try to understand:

- FOV vs pixel count and pixel size

- Scaling - especially "fit to screen" and 100% zoom level

 

[johnturley]

I think I get it now

The first of the 2 attached images  is virtually the same image taken the same night, but using a capture area of 800 x 600 instead of 1936 x 1096, the second image is actually this same image but enlarged by approximately 100% in GIMP.

I was confused by the fact that when I saved the first image back to my laptop, although it appeared approximately 100% larger on the laptop screen when imaging, it appeared to be the same size as the original image (but it wasn't), the second image though did appear approximately 100% larger on the laptop screen. 

I did not realise that had I posted the 800 x 600 image onto this site, unlike when viewing on my laptop, it would in fact appear about 100% larger than the original

It looks therefore that had a done a capture at around 400 x 300, it would appear the same size as the second of the 2 attached images (enlarged in GIMP), but would probably been sharper.

Maybe my 5x Powermate might now be redundant, I originally thought that I would need this to get decent sized images with the Esprit 150. I don't think I'll need to use GIMP either, but this program would have been useful for enlarging planetary images taken with my Canon 6D digital SLR, where you can't vary the capture area. 

John 

Edited August 27, 2022 by johnturley

[johnturley]

2 hours ago, johnturley said:

I think I get it now

The first of the 2 attached images  is virtually the same image taken the same night but using a capture area of 800 x 600 instead of 1936 x 1096, the second image is actually the same image but enlarged by approximately 100% in GIMP.

I was confused by the fact that when I saved the first image back to my laptop, although it appeared approximately 100% larger on the laptop screen when imaging, it appeared to be the same size as the original image (but it wasn't), the second image though did appear approximately 100% larger on the laptop. 

I did not realise that had I posted the 800 x 600 image onto this site, unlike when viewing on my laptop it would in fact appear about 100% larger than the original

It looks therefore that had a done a capture at around 400 x 300, it would appear the same size as the second of the 2 attached images (enlarged in GIMP), but would probably been sharper.

John 

This is the first image after being additionally processed in Lightroom, so hopefully getting there slowly, 2 of the Galilean satellites show up quite nicely,  

John

Edited August 27, 2022 by johnturley

[neil phillips]

4 hours ago, johnturley said:

This is the first image after being additionally processed in Lightroom, so hopefully getting there slowly, 2 of the Galilean satellites show up quite nicely,  

John

As Vlaiv says Use ROI During capture. It has more than one benefit from frame speed being faster. To smaller file size to get more storage out of your laptop. And to avoid display size confusing  you in the future just crop around the planet. It will prevent the display size from making your perceived images small. You will see the actual size of your planet image.  I never realized you didn't know larger surrounds resize the image to fit the whole image on the display.  How do you think it would fit it all in without doing that ? Hopefully now you can work on getting that 14" singing

Trust me in the right hands Jupiter would look stunning With that scope. If I had both your Esprit and the 14" to image with. For sure I would use the esprit. But the 14" would have the most potential by far. Good call from Vlaiv realizing you was confusing display size from planet size. That's such a given it didn't occur to me that you hadn't realized this. 

[johnturley]

14 hours ago, neil phillips said:

As Vlaiv says Use ROI During capture. It has more than one benefit from frame speed being faster. To smaller file size to get more storage out of your laptop. And to avoid display size confusing  you in the future just crop around the planet. It will prevent the display size from making your perceived images small. You will see the actual size of your planet image.  I never realized you didn't know larger surrounds resize the image to fit the whole image on the display.  How do you think it would fit it all in without doing that ? Hopefully now you can work on getting that 14" singing

Trust me in the right hands Jupiter would look stunning With that scope. If I had both your Esprit and the 14" to image with. For sure I would use the esprit. But the 14" would have the most potential by far. Good call from Vlaiv realizing you was confusing display size from planet size. That's such a given it didn't occur to me that you hadn't realized this. 

Neil

Although I'd taken a few images previously reducing the capture area from 1936 x 1096 to 800 x 600, I didn't appreciate until yesterday that although this gave a larger size on the laptop screen when imaging, when saved back to a file on my laptop after processing, Windows was shrinking the images so that they appeared to be the same size as if using the full 1936 x 1096, only they weren't. I hadn't before yesterday tried loading an image taken at 800 x 600, as they didn't appear any better, and I mistakenly though that at this smaller capture area, I would be losing definition. Yesterday after reading Vlaiv's comments I tried loading a 800 x 600 image, and found lo and behold it was approximately 2.5 x bigger, I previously though that imagers must be using programs like GIMP to increase the image size. So in fact I don't need GIMP at all (the results looked a bit washed out), although it might be useful if I was to want to load an image taken with my Canon 6D Digital SLR, where you can't change the capture area. I get the impression that you need to use a combination of optical amplification (with a Barlow or Powermate), and electronic amplification for best results. 

Maybe I should try an even smaller capture area (down to around 400 x 300), I am fortunate perhaps that my equatorial mount drive system (1980's technology 720 teeth brass RA wheel driven by synchronous motor and Variable Frequency Oscillator cf £25,000 Paramount Taurus mount has I think 480 teeth aluminium wheel) which at this amplification can keep an object fairly central on the laptop screen for at least 10 minutes (the Jupiter image above I think was about a 7 minute run time).

I have done a bit of imaging with the 14in Newtonian, but I couldn't say that the results were any better than through the Esprit, however that night atmospheric conditions were not great. I will try it again when atmospheric conditions are good, I think another of the advantages of the 14in, is that the brighter image allows a faster frame rate with the ASI 462.

I gather that some people prefer to image in RAW8 rather than RGB 24, as apparently this also allows a faster frame rate, but then you need programs like PIPP and/or Autostakkert to Debayer the images back into colour, I tried this once, but the colours ended up yuk, looks like you need to do quite a bit of image manipulation to get good colours doing this. Some people also prefer Autostakkert to Registax, I've tried it a couple of times but was not over impressed, although I can see the advantage if you image in RAW8, so each to their own.

John 

[neil phillips]

16 minutes ago, johnturley said:

Neil

Although I'd taken a few images previously reducing the capture area from 1936 x 1096 to 800 x 600, I didn't appreciate until yesterday that although this gave a larger size on the laptop screen when imaging, when saved back to a file on my laptop after processing, Windows was shrinking the images so that they appeared to be the same size as if using the full 1936 x 1096, only they weren't. I hadn't before yesterday tried loading an image taken at 800 x 600, as they didn't appear any better, and I mistakenly though that at this smaller capture area, I would be losing definition. Yesterday after reading Vlaiv's comments I tried loading a 800 x 600 image, and found lo and behold it was approximately 2.5 x bigger, I previously though that imagers must be using programs like GIMP to increase the image size. So in fact I don't need GIMP at all (the results looked a bit washed out), although it might be useful if I was to want to load an image taken with my Canon 6D Digital SLR, where you can't change the capture area. I get the impression that you need to use a combination of optical amplification (with a Barlow or Powermate), and electronic amplification for best results. 

Maybe I should try an even smaller capture area (down to around 400 x 300), I am fortunate perhaps that my equatorial mount drive system (1980's technology 720 teeth brass RA wheel driven by synchronous motor and Variable Frequency Oscillator cf £25,000 Paramount Taurus mount has I think 480 teeth aluminium wheel) which at this amplification can keep an object fairly central on the laptop screen for at least 10 minutes (the Jupiter image above I think was about a 7 minute run time).

I have done a bit of imaging with the 14in Newtonian, but I couldn't say that the results were any better than through the Esprit, however that night atmospheric conditions were not great. I will try it again when atmospheric conditions are good, I think another of the advantages of the 14in, is that the brighter image allows a faster frame rate with the ASI 462.

I gather that some people prefer to image in RAW8 rather than RGB 24, as apparently this also allows a faster frame rate, but then you need programs like PIPP and/or Autostakkert to Debayer the images back into colour, I tried this once, but the colours ended up yuk, looks like you need to do quite a bit of image manipulation to get good colours doing this. Some people also prefer Autostakkert to Registax, I've tried it a couple of times but was not over impressed, although I can see the advantage if you image in RAW8, so each to their own.

John 

Just use Raw 8. try 4 or 5 ms exposure 200 to 250 frames per second. record for 2.30. to 3 minuets  Make sure the 14 " is properly cooled a hour with a fan. And properly collimated. Do it when no jet stream is showing on a jet stream map. Dont give up. if results suck. you have to keep at it.

[neil phillips]

Btw lower that gain. your levels are too high. its burnt out in the middle. Use a histogram of 70% Sharpcap if your eyes cant tell when its over exposed

It will at least prevent burn out

Edited August 28, 2022 by neil phillips