Imaging Scope Reflector Advice

Heath (Heater) · #1 26-03-2011, 08:08 AM

Hi all,

Can anyone recommend a decent and affordable reflector for DSLR imaging?

Looking for a largish aperture, 200mm + and looking to spend between $800 - $1200 and somthing that could be mounted on an EQ6 Pro.

Using a full frame camera as well

Cheers Heath

A23649 (Nathan) · #2 26-03-2011, 10:31 AM

i am looking at the same type of thing so have a look at the Orion 8in/200mm. f/4.0 Newtonian Astrograph Reflector OTA. sirius optics sells them for $660 + postage. maybe you could check bintel for something similar

Heath (Heater) · #3 26-03-2011, 10:44 AM

That looks like a reasonably priced option.

tlgerdes (Trevor) · #4 26-03-2011, 11:57 AM

I have the Bintel/GSO 8" F4. They come in under $500, but you will need to add a coma corrector ($250) and a set of catseye collimation tools ($300). F4 is not for the faint hearted when it comes to collimation and a Laser is not close enough.

I choose the Bintel/GSO over the Orion as I felt their standard focuser was better.

tlgerdes (Trevor) · #5 26-03-2011, 12:07 PM

With full frame, you will get vignetting with either. They are more suitable for APS sized sensors. I get very minor vignetting on my APS Canon.

Gem (Grant) · #6 29-03-2011, 09:47 AM

Quote:

Originally Posted by tlgerdes

I have the Bintel/GSO 8" F4. They come in under $500, but you will need to add a coma corrector ($250) and a set of catseye collimation tools ($300). F4 is not for the faint hearted when it comes to collimation and a Laser is not close enough.

I choose the Bintel/GSO over the Orion as I felt their standard focuser was better.

You say that the F4 is difficult to collimate. I was looking at getting the 200mm f/4 GSO to put on a HEQ5 Pro. I am wanting to do both observing and later imaging. Would you recommend against it then? What is a catseye collimation tool? If it is $300 and necessary then it puts it out of my budget range! I was hoping to save weight by getting an f/4 over and f/5.

tlgerdes (Trevor) · #7 29-03-2011, 03:26 PM

Quote:

Originally Posted by Gem

You say that the F4 is difficult to collimate. I was looking at getting the 200mm f/4 GSO to put on a HEQ5 Pro. I am wanting to do both observing and later imaging. Would you recommend against it then? What is a catseye collimation tool? If it is $300 and necessary then it puts it out of my budget range! I was hoping to save weight by getting an f/4 over and f/5.

Weight saving is minimal between the F4 and F5. I would not recommend a a next on a EQ mount for visual (unless you are a contortionist or a masochist). The eyepiece will end up in all sorts of wonderous postions as it traverses the hemisphere.

A catseye is a collimation tool that is supremely acurate, much more so than lasers. See http://www.catseyecollimation.com/. Once you get the hang of it, it fairly easy, just be prepared to pull the OTA apart (which isnt hard) and re-assemble it to get things perfectly aligned.

Even with an ED80 or some other similar refractor you will still need a field flattener for photos, this will add another $300 to one of these.

As for weight, once you add guidescope, and camera you will be pushing the weight boundaries of the HEQ5, but it should hold (I will defer to high authorities on that matter)

Gem (Grant) · #8 29-03-2011, 03:53 PM

Thanks.
I know I will be pushing the weight limit, but that is why I was thinking of saving a little on getting a f/4 rather than a f/5 (as well as the short focal length being better for deep sky images).
I am new to equatorial mounts, having done most of my observing with a 10 inch dob. I am trying to find that balance between usability (light enough and short enough for frequent use in the backyard or being thrown into the boot of a camry), aperture for observing, budget constraints, and suitability for some imaging down the track. So far, my research seems to be pointing to an HEQ5 Pro with a 200mm reflector. However, I am willing to be persuaded otherwise!!
Should I be considering something like a 6 inch skywatcher refractor on an HEQ5 Pro? I remember as a kid being at star parties and thinking "bigger is better" whenever I looked through a 16 inch or 20 inch scope... *sigh*

ZeroID (Brent) · #9 04-04-2011, 12:25 PM

Why are you going with a 8" f4 or f5. Based on what I read an ED80 or ED100 at a fraction of the aperture does the job. So a smaller newt might work just as well.
I've just bought an EQ6 Pro but will use, at least for the meantime my 4.5" (114mm) F8 Newt with a NexImage SSI cam to get started. I'll look at other options when the bank balance recovers from the mount.

Heath (Heater) · #10 04-04-2011, 05:35 PM

How about a GSO 8" RCA f8 Ritchey Chretien?