Questions about planetary imaging using Celestron Nexstar & Canon 1100D

[edest]

Hi all,

I have a Celeston Nexstar 127 and a Canon 1100D. I'd like to be able to do some back planetary imaging and have purchased a Canon T ring for my Canon 1100D. I have a few questions (I am a complete noob at this - so forgive any silly questions and apols if this has been asked before).

1) Do I just use the T Ring to connect the camera to the scope? I've seen a bunch of thread on various forums that seem to offer conflicting advice and some say you can attach it directly using the T Ring whereas others say you need another adaptor and others say get an adaptor with a barlow in it (https://www.rothervalleyoptics.co.uk/celestron-x2-barlow-lens-with-t-adaptor-125.html)

2) How does the whole magnification thing work? (... see I told u I was a noob!!!). Visually I use different eyepieces to achieve different magnifications so how does this work with a DSLR camera attached directly with no eyepiece?

3) If the camera is connect to the scope using the T Ring how do I add in a moon filter into the mix?

4) What is the best way to take the photos (do I just press the button on the camera and risk moving it all, get a remote control button clicker or hook up to some software (I heard about Backyard EOS)?

5) Would I just be better off getting an astro camera (e.g. https://www.firstlightoptics.com/zwo-cameras/zwo-asi224mc-usb-3-colour-camera.html) rather than trying to use the DSLR camera?

Any tips would be really appreciated!!!

Many thanks in advance.

Ed 

[vlaiv]

Hi and welcome to SGL.

1 hour ago, edest said:

Do I just use the T Ring to connect the camera to the scope? I've seen a bunch of thread on various forums that seem to offer conflicting advice and some say you can attach it directly using the T Ring whereas others say you need another adaptor and others say get an adaptor with a barlow in it (https://www.rothervalleyoptics.co.uk/celestron-x2-barlow-lens-with-t-adaptor-125.html)

Your telescope should have T2 thread on rear opening. T ring will screw into that thread and will attach to camera as regular lens. This is enough to get your telescope connected to your camera. Some other scope designs do require barlow element because they can't reach focus regularly. This is usually the case with newtonian type telescopes.

1 hour ago, edest said:

2) How does the whole magnification thing work? (... see I told u I was a noob!!!). Visually I use different eyepieces to achieve different magnifications so how does this work with a DSLR camera attached directly with no eyepiece?

Magnification as a concept is not applicable to astrophotography. Magnification works by magnifying angles - when you look at eyepiece you get the image where object looks as if covering larger angular part of the sky.

In daytime observing like with spotter scope - you can think of magnification as "bringing object" closer - but it will look "larger" when closer because it subtends larger angle to your eyesight. Astronomical objects are effectively at infinity (as far as optics is concerned) - and no moving back or forth will change their apparent size.

With imaging it is about projection - how much pixels on sensor will be covered by certain angle on the sky. This is governed by focal length of telescope and pixel size of camera. You can't change that type of "magnification" easily. You either need to extend focal length (like using barlow lens) or reduce it (focal reducer) or change pixel size (change camera / bin pixels).

In the end when you make image, "magnification" of object really depends on how far away you stand when looking at the image, so image itself does not have magnification.

1 hour ago, edest said:

3) If the camera is connect to the scope using the T Ring how do I add in a moon filter into the mix?

There are things called filter wheels, filter drawers or just simply filter attachments. These have T2 threads (or other common threads) on both sides and can hold filter, so attaching a filter would be like

Telescope T2 - filter drawer with filter inside - T ring - camera

https://www.firstlightoptics.com/zwo-accessories/zwo-2-filter-drawer-m42-m48.html

or maybe this item:

https://www.firstlightoptics.com/zwo-filters/zwo-t2-to-125-filter-holder.html

Be sure to fully understand effect of filter on astrophotography before you use it (or get additional gear to use it) - it is not the same as for visual

1 hour ago, edest said:

4) What is the best way to take the photos (do I just press the button on the camera and risk moving it all, get a remote control button clicker or hook up to some software (I heard about Backyard EOS)?

Best way to take photos with telescope is to do it remotely - either by remote shutter or intervalometer or by computer control of camera.

Best way to take planetary photos is something called lucky imaging and DSLR type of camera is not well suited for that.

1 hour ago, edest said:

5) Would I just be better off getting an astro camera (e.g. https://www.firstlightoptics.com/zwo-cameras/zwo-asi224mc-usb-3-colour-camera.html) rather than trying to use the DSLR camera?

Yes, that would be best way to proceed, but do first look at some tutorials on how to capture and process planetary imaging using lucky imaging technique.

It is very different to what we consider "taking a picture". Involves quite a lot of software processing and it would be good that you get the idea of what it all means.

[edest]

Thank you so much for such a detailed and useful answer - that is really helpful and I appreciate your time.

Regards,

Ed

[newbie alert]

Planetary cams and lucky imaging is the way to go..

A dedicated planetary cam will have a rapid frame rate compared to a DSLR  here's the fov on Jupiter with your scope/ camera, compared to the 224 that Vlaiv suggested

[newbie alert]

A good source of working out fov with different setups is astromany tools fov 

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

[michael8554]

Image with the 1100D in 5x LiveView mode 848 x 568, to give non-compressed non-interpolated video.

https://www.astropix.com/html/equipment/canon_one_to_one_pixel_resolution.html

Michael

Edited December 30, 2021 by michael8554