Solar system scope suggestions?

[GlassWalker]

I think I may be a shopoholic... anyway, last night I had a stab at imaging the moon and Jupiter, and I decided I need more aperture to get around diffraction and give me some amount of useful light to gather I'm not going into this too seriously, so am looking on the cheap end, say "several hundreds of £".

What I ended up using was a Celestron Nexstar 4 (102mm mak) and for Jupiter even with a 2x barlow it was barely more than a tiny blob in the DMK41 as below if the following image link works:

So I'm wondering what's a value option to get say double the aperture I have now? Something around 200mm, unless you can get much more without breaking the bank? I'm saving for deep sky kit too! How about the Skywatcher 200PDS newt for around £300? Not too long natively so should give decent amounts of the moon as is, and stick a big barlow on if planet hunting. Am I overlooking anything that would make this a bad idea? Or is there another option that would give better results in a similar ball park cost? If another 8 inch newt costs a bit more, but is better built (focuser or whatever) then that could be a consideration too.

[Bizibilder]

How about a SW 150 or 180 MAK? - exellent for planets and Lunar and "several hunderd £" will get you one.

[GlassWalker]

I'd love a mak or even SCT for their smaller size and what feels like more sturdy build, but for a comparable aperture over a newt I'm looking at doubling the price...

[ollypenrice]

For imaging the planets you also need focal length and piling up barlows is likely to pile up errors as well. Starting with a long slow optic has to be a better idea surely? The Mak strikes me as the best path, or a larger SCT. There are lots of second hand ones because folks going into DS imaging don't find them easy to deal with for this job (because they're not!) But on the planets, yes.

Olly

[GlassWalker]

Actually I'm planning my main future purchases for deep sky improvement also. Hence wanting to get a planetary upgrade on minimal cost. But good point, I didn't consider looking for used kit, which might just swing the balance.

[JamesF]

As you already have the EQ6, I'd have thought that a second hand C8, C9.25, 150 or 180 Mak would be where you should be heading. A decent newt will do an awful lot of stuff well, but for planetary imaging you're probably looking at wanting a focal ratio of f/30 to f/40 if you can manage it, and that's really not easy with many modern newts, whereas f/35 isn't even that challenging with my 127 Mak.

I don't know much about the DMK41, but I do know that it's perhaps not the ideal camera for planetary imaging because the bandwidth required for a single frame limits the maximum potential frame rate. There may be ways around that, but if there are I'm not aware of them.

James

[GlassWalker]

The DMK41 I chose for solar to get a wider field of view at a limit of 15fps. I know, that's not ideal for planetary, but I'm thinking "making the best of what I got, or can get cheaply" here. Not throw a ton of cash to get the best.

And am I missing something here. Even if I go as long as 1/15s exposures with the DMK41, at focal length 2650mm f/26 that I was using the other night, it was very dim already and I needed to whack up the gain on the camera. If I were to go to f/40 that'll be less than half that. A new newt at £300 gets me a focal length of 1000mm f/5, stick a 5x barlow on that which seems about as high as they go, I have 5m f/25. Roughly double the image size for the same brightness.

I'd love one of the SCTs, particularly the models that can go hyperstar, but I'm not having luck finding used ones so far. Nor maks.

[JamesF]

It could just be that you need more aperture to get sufficient image brightness at an acceptable scale. I've not yet tried Jupiter this season, but with Mars this spring for example I was using the 127 Mak at a focal ratio of around f/30 to f/35 and an SPC900 and getting quite acceptable results:

I've seen a few 127 Maks and C6's for sale in the classifieds, but the larger SCTs and Maks don't seem to come up too often, I agree. Perhaps there's a good reason for that

James

[GlassWalker]

Is it bad that I've never looked in the classified section on this site before? Actually, that could also be a good thing as I still have a roof over my head Today I just ordered a pier so that'll eat up the month's budget, and I have more time to look at any possible new scope...

Oh, since I've primarily done widefield deep sky in the past, I've never been bothered about seeing conditions as long as the sky looks transparent enough. I recall suggestions elsewhere that shorter exposures could give better detail than longer ones due to less movement integration time. Of course the high fps cameras would be limited by that if running at full speed, but I'm wondering what a good exposure time would be, and how to deal with the lack of light at that point.