Galaxy imaging

[Wonderweb]

Hi. 

I have been playing around with different scopes and imaging setups (deep sky, wide field, galaxy and planetary) and I have realised that the last 2 are currently where my passion lies and I have a couple of questions.

Would something like a celestron nexstar evolution 9.25 be a good crossover scope (x2 barlow for planetary and 0.63 reducer for galaxies)? 

What camera would you recommend to give a good pixel scale for galaxy imaging? I currently have an altair astro 269c which at 3.3 micron, if I went for something like the c9.25 is oversampling. 

Thanks in advance 

[michael.h.f.wilkinson]

I think the C9.25 would be a bit long in terms of focal length, even with the 0.63x reducer. Outstanding for planets, however.

[ONIKKINEN]

What sort of budget are we looking at here?

What mount will the scope be put on, and where (observatory/traveler/backyard etc)?

Not sure how to advice without knowing these first.

[Wonderweb]

27 minutes ago, michael.h.f.wilkinson said:

I think the C9.25 would be a bit long in terms of focal length, even with the 0.63x reducer. Outstanding for planets, however.

Do you think an 8se or something like that would be better or would you recommend something else? If I had to lean one way I'd prefer something best suited to galaxy imaging. 

[Wonderweb]

3 minutes ago, ONIKKINEN said:

What sort of budget are we looking at here?

What mount will the scope be put on, and where (observatory/traveler/backyard etc)?

Not sure how to advice without knowing these first.

I have an eq6r pro which I will be putting in my observatory when I get round to building it. In the mean time I use it on my back yard. I currently have an rc6 which is a swine to collimate and im never fully happy with. I would be willing to go up to around £1000 for the right scope. 

[michael.h.f.wilkinson]

3 minutes ago, Wonderweb said:

Do you think an 8se or something like that would be better or would you recommend something else? If I had to lean one way I'd prefer something best suited to galaxy imaging. 

The 8se doesn't have the right mount for DSO imaging. I use a Meade SN6 6" F/5 Schmidt-Newton which works nicely.

I am also trying to get a Starizona Night Owl 0.4x reducer for my GP-C8 (C8 on Vixen Great Polaris mount). That would work well with my ASI183MM-Pro. 

 

[Wonderweb]

I have an eq6r pro mount so would only be looking for the ota. I picked the 8se off the top of my head as the next size scope down from the 9.25. 

[ONIKKINEN]

3 hours ago, Wonderweb said:

I have an eq6r pro which I will be putting in my observatory when I get round to building it. In the mean time I use it on my back yard. I currently have an rc6 which is a swine to collimate and im never fully happy with. I would be willing to go up to around £1000 for the right scope. 

Hmm, for new scopes there isn't much to choose from at this price point. Looking at SCTs you could get a 6'' SCT but honestly i would think the RC6 is a better performer if it held collimation. You could get a 200PDS with money left over for a good coma corrector and some other bits and that would make a pretty fast galaxy scope, but since its a newtonian you would still have to deal with keeping the thing collimated and possibly remedy some other newtonian issues. For used scopes, well anything goes since prices are not set in stone.

If you do have a deal on a C9.25 that you could get for a price you like, you can use it with the 0.63x reducer with your current camera, provided that you bin or sample accordingly with other means, like super pixel debayering. So if you dont want to upgrade your camera for other reasons, know that you dont really have to. With the 0.63x you would still fit M33 comfortably on the 269, and everything other than M31 will be smaller than this so i would say its good to go.

[nfotis]

If I understand correctly, you have already a quite good mount (EQ6-R), so no reason to get a second Celestron mount, only the OTA.

For galaxy imaging, you probably want around 2000 to 2800mm focal length (if you have a large enough sensor). So, a C8 or C9.25 should be fine with your 4/3rds sensor and an OAG. Few targets like M31 and Pleiades won't fit the combination, even with a 0.67x reducer. If you plan on doing often DSO imaging, the EdgeHD version would be preferable.

For planetary imaging, a 2x Barlow and a planetary camera like the ASI462MC should be a quite potent combination with the SCT.

N.F.

 

[Clarkey]

22 hours ago, Wonderweb said:

I currently have an rc6 which is a swine to collimate and im never fully happy with.

Not sure why. Yes they are a bit fiddly, but the collimation should not be too bad. There are a number of guides available, I use a modified version of the DSI method. Once set up they are ideal for galaxy imaging. I have an RC8 and I have to bin to get a reasonable pixel scale so there is not too much benefit in a longer FL. I think the 2000 plus requirement suggested is excessive as at that scale an AZ-EQ6 is probably at its limit and the scope will be quite slow. Ok for planetary though.

[CCD-Freak]

I use my Astro Tech 10"RC "Galaxy Cannon" at 2000 mm to get up close and personal with galaxies.  I have been using an ASI-533MCP with good results even though it is over sampled at .39" / pixel. 

I find bad seeing is the biggest obstacle when imaging at 2000 mm FL. 

I recently found a carbon fiber version AT10RC that I will be using for galaxy season this year along with an ASI-2600MCP.

[iapa]

On 14/02/2022 at 22:33, michael.h.f.wilkinson said:

The 8se doesn't have the right mount for DSO imaging. I use a Meade SN6 6" F/5 Schmidt-Newton which works nicely.

I am also trying to get a Starizona Night Owl 0.4x reducer for my GP-C8 (C8 on Vixen Great Polaris mount). That would work well with my ASI183MM-Pro. 

 

There’s the option on the Celestron 8" SCT ota

https://www.firstlightoptics.com/optical-tube-assemblies/celestron-c8-xlt-optical-tube-assembly-cge-losmandy.html

i bought the OTA on this site from an 8SE sans mount, I quite like it.

On 15/02/2022 at 02:26, ONIKKINEN said:

Hmm, for new scopes there isn't much to choose from at this price point. Looking at SCTs you could get a 6'' SCT but honestly i would think the RC6 is a better performer if it held collimation. You could get a 200PDS with money left over for a good coma corrector and some other bits and that would make a pretty fast galaxy scope, but since its a newtonian you would still have to deal with keeping the thing collimated and possibly remedy some other newtonian issues. For used scopes, well anything goes since prices are not set in stone.

If you do have a deal on a C9.25 that you could get for a price you like, you can use it with the 0.63x reducer with your current camera, provided that you bin or sample accordingly with other means, like super pixel debayering. So if you dont want to upgrade your camera for other reasons, know that you dont really have to. With the 0.63x you would still fit M33 comfortably on the 269, and everything other than M31 will be smaller than this so i would say its good to go.

I’d say that the 200PDS is a good reasonably priced option if permanently mounted in an observatory, I found collimation can hold for a year or so.

 

[iapa]

Just spotted that someone in this forum is looking to sell an 8SE