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Akmcf

Help with terminology, equipment & reassurance!

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Posted (edited)

Hi guys! 🙂

My name is Andrew, I only just stumbled across these forums just now! Couldn’t have come across a better community to help me with some questions I have!

 

So I’ve Come to the conclusion that I’m going to be buying a Celestron Nexstar 6SE telescope everything about it appeals to me. I currently own a much older manual celestron telescope and am ready for my first proper telescope!

I do plenty of photography and own a DSLR and am aware that with this telescope that it comes with a software that will record video of what you’re gazing at and stack the images if I’m correct?

because I’m familiar with normal photography and not so much with Astro photography I was wondering if anyone could help me out. For the stocking software, is that all the process completed within the telescope and no DSLR? Or is that recorded with the DSL are and then the software stacks? What kind of adapters would I need to be getting into AP? By the way I’m looking at mainly photographing the moon and hopefully get some awesome shots of the other planets too! 😄 not so much deep AP, as from my research I’ve gathered that this isn’t the greatest for it... anyways.

 

Is it better to use a DSLR and an adapter on the eyepiece for imaging? Or the stacking and what would I need for best result stacking images, especially of planets like Saturn and Jupiter?! Are the individual eyepiece attachments you buy for the telescope, cameras in themselves? What is aci?  I’ve got no clue! Haha a lot to learn!
 

I thought I was on the right track looking by myself for equipment and I came across the 10MP celestron Neximage eyepiece or whatever it is? I’m not entirely sure? And also what is a T ring? Is that a Dslr adapter? Does the stacking software come with the telescope or with additional purchases?!

Sorry for the bombardment of questions! Obviously I’m very excited to get going and am very keen on getting some equipment! Any answers are much appreciated!

Have a great day!

 

Andrew :)

Edited by Akmcf

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Hi Andrew and welcome to SGL.

If you are interested in planetary imaging Celestron Nexstar 6SE is very decent option (for visual astronomy as well).

Stacking software is something that you can either purchase or download for free. In fact, software most used for planetary type imaging is free (some require purchasing a license but you have free/open source alternatives). Most of software that you'll use accept donations as well - so you can donate some money to keep software evolving and being better.

Planetary imaging works by taking "a movie" - or rather fast succession of stills and then stacking those - or some of those "subs". You stacks ones that are not terribly ruined by atmospheric seeing. Software automates this for you and selects best N% of frames (you tell it how much subframes you want to stack). Then there is sharpening and post processing stage.

You can use DSLR to record a movie, but better option is to purchase dedicated astronomy camera for that. Not terribly expensive. 10MP celestron Neximage "eyepiece" - is one such camera, but I would recommend you to purchase something like this instead:

https://www.firstlightoptics.com/zwo-cameras/zwo-asi224mc-usb-3-colour-camera.html

Or if you want a bit more resolution / larger sensor (but a bit more expensive):

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-385mc-usb-30-colour-camera.html

You'll need a barlow lens (but not necessary - it will only help you reach maximum "zoom" that you can use) - don't go crazy on magnification and get x3 or x5 - x2 will be enough with your scope. Better yet - get telecentric lens like this one:

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-2x-3x-5x-barlow-focal-extender-125.html

T ring is adapter to attach DSLR to your telescope. It converts from lens mount of camera to one of standard threads in astro applications - there are few most popular ones like T2 (so T ring is actually T2 ring :D ), M48 or 2" and 1.25" (which has M28 thread) T2 is M42 if I'm not mistaken but with fine pitch (regular M42 has 1mm while T2 has 0.75mm) - but take these as intro into what exists and not hard facts on mm sizes (I could be wrong - worth checking elsewhere).

T ring will be needed only if you plan to image with DSLR. Btw - It's worth doing for lunar if you want to go for whole moon shots instead close up - you can do that with regular images (not video) - just shoot bunch of them (like couple of dozen) and stack those. Sometimes people don't bother with stacking and just shoot couple of frames and pick the sharpest one.

Hope this helps, and I'm sure other members will contribute with their views and advice.

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Posted (edited)

vlaiv has pretty much covered it, but I'll add a few extras. :smile:

The telescope itself has no software for recording or processing images. With a DSLR you can record a video standalone but it's much easier using capture software like APT which runs on your Windows computer.

The camera takes the place of the eyepiece and is generally not used with an eyepiece as well so the telescope is in effect  just a long focal length camera lens. Astro cameras come with an adapter to enable them to be fitted to the scope just like an eyepiece would be. DSLRs require an appropriate T2 adapter to attach themselves to the scope.

As vlaiv said a dedicated astro camera can be a lot easier to work with as there are more software options for image capture like Firecapture or Sharpcap which are free or cost very little for some extra features. I believe there is an Ascom driver written for Canon DSLRs which does enable them to work with Sharpcap. Ascom is a 'standard' interface to allow Astro programs and hardware to communicate with each other.

Astro cameras also enable recording in an uncompressed video format which is much better for stacking to get better quality images, than using compressed video formats like you get with DSLRs (.mov or .mp4) The compression artefacts negate some of the benefits of stacking. Also many DSLR video formats downsample the sensor image size to match the common video size formats and aspect ratios which loses more resolution. A few DSLRs do allow centre cropped video recording where only the centre of the sensor which pixel matches the video format is used. This enables a sharper recording than the downsampled full frame version. Most Canons can be adapted to use cropped video recording if the Magic Lantern firmware is installed in the camera alongside the Canon firnware.

DSLRs only allow video recording in standard video framerates of 25 or 30fps (maybe higher in newer models, not sure). Astro cameras allow you to select a Region Of Interest (ROI) to record rather than the full frame (very useful for planets as they generally only cover a relatively small portion of the sensor). This enables much higher framerates up to 200fps or so to be used so you can record thousands of frames in 30 seconds or so. 

Stacking selects the best frames of the video to stack to give the sharpest image but the main benefit of stacking is greatly improving the signal to noise of the final stacked image allowing quite heavy sharpening effects to be applied without bringing up the noise too much.

Autostakkert is a free commonly used video stacking program and Imppg (also free) gives good deconvolution sharpening routines. Photoshop etc. can be used instead or as well.

Hope this helps. And I don't know what 'aci' is either 😀

Alan

Edited by symmetal
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13 hours ago, vlaiv said:

Hi Andrew and welcome to SGL.

If you are interested in planetary imaging Celestron Nexstar 6SE is very decent option (for visual astronomy as well).

Stacking software is something that you can either purchase or download for free. In fact, software most used for planetary type imaging is free (some require purchasing a license but you have free/open source alternatives). Most of software that you'll use accept donations as well - so you can donate some money to keep software evolving and being better.

Planetary imaging works by taking "a movie" - or rather fast succession of stills and then stacking those - or some of those "subs". You stacks ones that are not terribly ruined by atmospheric seeing. Software automates this for you and selects best N% of frames (you tell it how much subframes you want to stack). Then there is sharpening and post processing stage.

You can use DSLR to record a movie, but better option is to purchase dedicated astronomy camera for that. Not terribly expensive. 10MP celestron Neximage "eyepiece" - is one such camera, but I would recommend you to purchase something like this instead:

https://www.firstlightoptics.com/zwo-cameras/zwo-asi224mc-usb-3-colour-camera.html

Or if you want a bit more resolution / larger sensor (but a bit more expensive):

https://www.firstlightoptics.com/zwo-cameras/zwo-asi-385mc-usb-30-colour-camera.html

You'll need a barlow lens (but not necessary - it will only help you reach maximum "zoom" that you can use) - don't go crazy on magnification and get x3 or x5 - x2 will be enough with your scope. Better yet - get telecentric lens like this one:

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-2x-3x-5x-barlow-focal-extender-125.html

T ring is adapter to attach DSLR to your telescope. It converts from lens mount of camera to one of standard threads in astro applications - there are few most popular ones like T2 (so T ring is actually T2 ring :D ), M48 or 2" and 1.25" (which has M28 thread) T2 is M42 if I'm not mistaken but with fine pitch (regular M42 has 1mm while T2 has 0.75mm) - but take these as intro into what exists and not hard facts on mm sizes (I could be wrong - worth checking elsewhere).

T ring will be needed only if you plan to image with DSLR. Btw - It's worth doing for lunar if you want to go for whole moon shots instead close up - you can do that with regular images (not video) - just shoot bunch of them (like couple of dozen) and stack those. Sometimes people don't bother with stacking and just shoot couple of frames and pick the sharpest one.

Hope this helps, and I'm sure other members will contribute with their views and advice.

Thank you so much for your response! Some forums can be really hard to get good information out of, especially being new, so thanks so much for your help!

You've answered pretty much everything I could've asked for!

So ultimately I'd be looking at the Celestron 6SE, and also a 'camera eyepiece' thingo which you have linked above? But also like you said, I also would want a T ring for the lunar photography, and just another question, I was watching videos last night using this telescope, is it a good option to purchase a focal reducer for lunar photography? I was watching videos on how they would be awesome for like you said 'full moon shots' instead of close ups, or is there a better option? 

So from my understanding, obviously for the planetary photography the stacking and eyepiece cameras are the best option, without a doubt. However for the moon, would the stacking software and camera eyepiece be the better option for close up lunar too? then DSLR with a T ring and or (focal reducer) if I have the right idea, for further away shots? 

 

Thank you so much to the both of you for your replies!

 

Andrew 😄

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If you look under the "Resources" tab above you will see Field of View calculator. Here you can input details of your scope and camera in the "imaging" tab and it lets you see what your FOV will be like i.e. your image. I doubt that you will want a focal reducer.

Peter

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3 minutes ago, Akmcf said:

Thank you so much for your response! Some forums can be really hard to get good information out of, especially being new, so thanks so much for your help!

You've answered pretty much everything I could've asked for!

So ultimately I'd be looking at the Celestron 6SE, and also a 'camera eyepiece' thingo which you have linked above? But also like you said, I also would want a T ring for the lunar photography, and just another question, I was watching videos last night using this telescope, is it a good option to purchase a focal reducer for lunar photography? I was watching videos on how they would be awesome for like you said 'full moon shots' instead of close ups, or is there a better option? 

So from my understanding, obviously for the planetary photography the stacking and eyepiece cameras are the best option, without a doubt. However for the moon, would the stacking software and camera eyepiece be the better option for close up lunar too? then DSLR with a T ring and or (focal reducer) if I have the right idea, for further away shots? 

 

Thank you so much to the both of you for your replies!

 

Andrew 😄

You can check it here:

https://astronomy.tools/calculators/field_of_view/

I've compared two sensor sizes for you - APS-C and full frame:

image.png.68581ad56b25f97b31f159aa0925409e.png

I doubt that this scope is usable on full frame sensor without reducer / corrector, and even APS-C will benefit from it.

You can also use DSLR and dedicated astro camera to get full disk images with special technique - mosaics. In astronomy most objects are relatively static so you can take multiple images of different parts and stitch them together much like panorama images. If your camera does not have enough field of view to fit whole disk - you can always use this approach and in fact many people do.

If you visit lunar imaging section of the forums you'll discover that many images are made just like that, for example here:

Author used 3 panels to get image done.

Here it took 19 panels to get complete image:

 

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On 11/05/2020 at 17:29, vlaiv said:

You can check it here:

https://astronomy.tools/calculators/field_of_view/

I've compared two sensor sizes for you - APS-C and full frame:

image.png.68581ad56b25f97b31f159aa0925409e.png

I doubt that this scope is usable on full frame sensor without reducer / corrector, and even APS-C will benefit from it.

You can also use DSLR and dedicated astro camera to get full disk images with special technique - mosaics. In astronomy most objects are relatively static so you can take multiple images of different parts and stitch them together much like panorama images. If your camera does not have enough field of view to fit whole disk - you can always use this approach and in fact many people do.

If you visit lunar imaging section of the forums you'll discover that many images are made just like that, for example here:

Author used 3 panels to get image done.

Here it took 19 panels to get complete image:

 

Okay perfect, thanks so much for your help!

Those images are absolutely incredible...

Looking forward to sticking with this community for the long run!

 

Can't thank you enough,

 

Kind regards,

 

Andrew :)

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