Next step up ... imaging scope

[toryglen-boy]

Howdy

I use an Orion ED80 for imaging (thanks Brian) but am thinking long term about what might be the best OTA to get next, for imaging? what would be a reasonable step up from the ED80, to half exposure times, and get more detail? i kinda had in my head something like an 8" F5 reflector, or something like that.

what did you go to, from your first imaging scope, to your second?

thanks

:thumbsup:

[turbo_pascale]

Everyone will have an opinion on this, but it depends on the kinds of images you want to take. If you want to go long focal length stuff, perhaps one of the Meade ACF OTA's (depending on the weight limit of the EQ6).

Depends on your budget too!

Turbo

[toryglen-boy]

Hi Fella

more interested in DSO's etc. than anything else really, so am thinking shortish ... F5 - F6ish. limit for a new OTA? say about $1K

although this is all pie in the sky, and hypothetical

:)

[Paul Haese]

This is where you will find yourself wondering which way to go.

Do you want to image galaxies and planetary nebula or just nebula?

Each requires different focal lengths.

Added to this, you will want a flat field which is coma free(well not initially but after a couple of months you will), so you need to figure a coma corrector and flattener into the purchase of a newtonian if you go this way. Or you could simply buy a telescope that has this already figures.

The budget certainly limits what you can buy. Either go for refractor (spend a bit more) or something you can correct later.

[turbo_pascale]

DSO + DSLR = tiny images except for the biggies (like M42, Eta Carinae etc)
Thinking you might need some more focal length. The budget is also a bit of a restrictive element.
Try downloading CCDCalc (http://newastro.wodaski.com/book_new/camera_app.php) to try various scopes/apertures/f-ratios with your 1000D specs for the sensor and see if the kinds of images you would like to take will be compatible with the style of gear you would like. There is a second link on that page with all of Messier objects to supplement the images that come with it, which should be a pretty good selection to give you a feel for what you can capture at various sizes (assuming your camera has enough sensitivity etc!!!!)

Personally, I'd be saving up a few more $K (maybe have $3-4K) and you open up a lot of options. The 80ED is good for widefield, and you need something a bit more dedicated for the longer FL stuff. No use taking baby steps with this sort of stuff - you end up losing every time you sell.

Turbo

[toryglen-boy]

i have a Baader MPCC, so thats coma covered.

:thumbsup:

[Bolts_Tweed]

Gday Duncan - I am the worst possible person tomake reccomendations (just bought a 10" ACF and a top end 4" TV refractor - both suggested below). I would however suggest you also consider one of the better 6" f6'ish Mak Newts around. I just got hold of asecond hand Intes MN61 however I notice Orion have one available and believe it or not skywatcher have one coming out (on thier web page). Looking at the O'seas results with the Orion they seem to stand up and I am not suggestiing they are the quality of Intes (maybe they are but I just dont know) you could have a look at Eddie Trimachis web page and his comments re the Intes. http://astroshed.com/

Yeah there are some collimation considerations but once you learn the procedure it is fine.

Anyway - just another one to consider.

MB

[TrevorW]

Duncan lad $1000 is going to limit you to a Newt

you have an EQ6

so IMO go for the f/5 10" Skywatcher BD Newt with revised focuser for imaging

the MPCC should work with it and was to be my choice before buying the GSO RC

By the way what I PM'd the other day was it of help

Cheers

[AlexN]

You really need to decide what you want to image, and a focal length you'd like to image at. There is simply no point looking at every scope there is in the market and trying to pick the "best" one.

Decide if you like wider field shots (400~700mm F/L) moderate (700~1300mm) moderate long (1300~1700mm) or long (1700~3000mm) Decide simply by looking through the forums at images, take note of the ones that strike you the most, and take note of the focal length...

Bare in mind that 1700~3000mm is extreme, will take either an incredibly stead fast resolve or a really expensive mount to pull off great images in this range..

Once you've chosen your desired focal length, you'll notice your list of possible scopes has become much more manageable. From there look at their pro's and cons, consider the camera you will be using with the scop, and determine what your needs are in terms of F/ ratio..

This is pretty much the process I go through when picking a scope..

General rules of thumb. anything with glass in the optical system is either going to be really expensive, or have some form of aberration, this can be true for purely reflective systems too. but often a "cheap" APO telescope will exhibit less than perfect colour correction.. Generally speaking, If I were looking to spend less than $1000 on an imaging telescope I would steer clear of refractors.. Thats not to say there are no good refractors sub $1000, just to say they are not considered common... Reflective systems under a grand you've got newtonians which deliver sharp images when collimated properly, maintainance can be a pain though, as collimation will generally go out every time you physically move the telescope, cassegrains (maks, SCT, RC's) These vary in quality, some mak casses are really nice, some are not, SCT's arent really an imagers dream scope due to the moving primary mirror, rather large spot size and a sealed tube which makes them hard to cool, RC's are generally out of the price range, however the 6" GSO RC is 1390 or there abouts I think.. However I dont kow anyone who has bought a 6" one yet, so there is no testing done, also they are an F/9 system, meaning that you'll have to be taking some long exposures to get serious data...

Mak Newts do make great imaging scopes when set up correctly...

I know there is a 10" F/3.5 Meade Schmidt Newtonian for sale on the forums at the moment, which would make a FINE imaging scope.. Collimation on these is apparently fairly tricky however, the results would be stunning with a large imaging sensor like a DSLR..

There are simply too many options out there to ask the broad question "what should I buy?" You could follow the route I've gone, and try to own one of everything at one stage or another to find out for yourself what works best, Or you could be smart with your money, narrow down your search perameters and find what is going to be the best for what you want to do before spending truckloads of money on numerous telescopes!!

If I had my way, I'd own a 10" newt, a 14" SCT, an 80~100mm fluorite triplet APO, maybe one of those Intes Mak Newts and an RC with a mount big enough to carry them all at once.. :)

[jjjnettie]

Not an easy decision is it Duncan.

[RobF]

Be interested to hear how it turns out Duncan. My wallet is with Trevor (Newt) and my imagination with Alex!

I always knew my budget would be limited, and have been over the moon with what's possible with an 8" Newt - will keep me plenty busy for a while to come. Ezystyles (Eric) is many people's idol on the newt imaging side here at IIS. Don't know if you're familiar with his work, but pretty much all done with 8 and 10" Newts with corrector and pollution filters:
http://www.ezystyles.com.au/

[White Rabbit]

Interesting thread, I'm thinking of upgrading my scope as well. Very informative indeed.

Thanks guys.

Sandy

[pmrid]

That is a sensible choice. Beware the temptation to go too big. I recently sold a 16" Dob and an LX200GPS Maksutov and settled on a 5" refractor I built myself and an 8" Nwtonian F/5. Each has drawbacks though and inevitably more $$ has to go into things like Coma Corrector on the newt and a UV Killer filter for the refractor. For my standard of imaging (beginner level), these are more than enough. The bottom line is I have 2 scopes I will actually use rather than 2 scopes I could barely use.
I also have a little 90mm Maksutov as a traveller - just in case you get caught by the roadside and .... well, you know that story I'm sure.
Peter