Which Scope?

[ilyas]

What should I buy for a Canon 40D (Astrophotography): a Celestron EdgeHD 8" AVX or a Celestron AVX SCT 9.25" since the price differs only for 100EUR? I want to have nice DSO pictures but be able to see planets as well. Been using a 114mm reflector for 6 years. 

 

Thanks in advance

[Galen Gilmore]

22 minutes ago, ilyas said:

What should I buy for a Canon 40D (Astrophotography): a Celestron EdgeHD 8" AVX or a Celestron AVX SCT 9.25" since the price differs only for 100EUR? I want to have nice DSO pictures but be able to see planets as well. Been using a 114mm reflector for 6 years. 

 

Thanks in advance

Your the person from Quora! Welcome to SGL!

Threre is no one telescope that is great for both DSO's and planets, but every telescope can see the moon, Jupiters cloud bands, and the rings of Saturn. An ED80 refractor can take great photos of DSO's, and with the right eyepieces can see all 9 of the planets, though the detail and brightness is limited.

[newbie alert]

2 hours ago, Galen Gilmore said:

Your the person from Quora! Welcome to SGL!

Threre is no one telescope that is great for both DSO's and planets, but every telescope can see the moon, Jupiters cloud bands, and the rings of Saturn. An ED80 refractor can take great photos of DSO's, and with the right eyepieces can see all 9 of the planets, though the detail and brightness is limited.

A ed80 has a focal length of 600mm

An 8 inch has a 2003mm..a 9.25 2350 odd.. an 8 inch has a aperture of 200mm instead of 80 for the ed.. and f ratio, use a reducer/flattener to bring it to f6.3..on the ed80 use a .85 and it's at f6.37..

The 80ed only comes into it's own on the bigger targets,guiding at a shorter fl is easier and you will get slightly longer exposure times..

Saying that I also think that using a sct with a DSLR on planetary imaging isn't the best way forward,a designated planetary camera is far,far better..

I'm not biased as I use both.. 

[ronin]

An SCT is usually not the ideal for astrophotography, at least at the DSO aspect, they are a nice visual scope but to use one for AP you will need a reducer at least and I suspect a more solid mount then the AVX.

For AP the scope characteristics tends to be fairly small and fast (f number) the scopes you have listed are kind of big and slow.

For AP you can start with a 400D but the internal filter will remove about 80% of the Ha wavelength, several targets are rich in the Ha wavelength, that is why people have them modified. However after that they are no longer suitable for everyday photography.

Planets are usually imaged as a video through the eqivalent of a webcam. You get the video, feed the video into software and determine the "best" frame then get the software to stack the best 20% that match this best frame. The purpose is to stack just good frames, not all frames.

So good DSO imaging scopes are ones like the William Optics Star 71, WO GT-81, Skywatcher 80ED, ES 80mm FCD-100, SW 130PDS. Some people will go and use 100mm scopes.

One aspect that seems to occur is that the packages offered like a scope on a mount are aimed at the visual side, not the AP aspect. Usually means they are not necessarily good at imaging, and for visual the mount needs not be so solid. So you get a mount that is only just up to handling the scope. For AP people tend to go buy the scope they want and the mount they want as individual items. So a "package" tends to not be something well suited to AP.

 

[newbie alert]

1 hour ago, ronin said:

For AP the scope characteristics tends to be fairly small and fast (f number) the scopes you have listed are kind of big and slow.

 

1 hour ago, ronin said:

So good DSO imaging scopes are ones like the William Optics Star 71, WO GT-81, Skywatcher 80ED, ES 80mm FCD-100, SW 130PDS. Some people will go and use 100mm scopes

It's not the f ratio that makes a sct difficult to use AP,as I said in the above post a 8 inch sct with a reducer is @6.3..but you recommend the 80ed which with a .85 reducer is at 6.375.. so the ed80 is slower than the sct.. . It's the focal length.. .

I agree that it difficult with a sct but not impossible.. the 80ed is easier to use..but I'd rather image the ring neb or m51 with my sct than my ed80..and rather image say the rosette or m45 with the 80ed,and also using a avx..