Trying something different

[Mickoid (Michael)]

SW Esprit 100 with a 2.5 X Powermate. Aproximate focal length 1375mm, focal ratio about f 14. M83- 12 x 150 secs, M104 9 x 150 secs both guided using PHD2 on an HEQ5pro mount. Shot with a modded Canon 550d, UVIR cut filter at 1600 iso. Bortle 6 skies.

Just a test I did last night to see if this was possible. Results are encouraging.

[Startrek (Martin)]

Mick
Interesting unconventional concept with fairly good results
I tried a couple of years ago using a Powermate on my DSLR imaging the Carina Nebula with short subs to try and zoom in close but resolution suffered greatly so gave the idea away
I’ll stick to planetary imaging with my Powermates where they excel
Cheers
Martin

[Mickoid (Michael)]

Thanks for the comment Martin. The real test would be to obtain more data, like you said in one of your posts - you need a minimum of 2 hrs on galaxies. These images were 30 mins and less. My test was to see whether increasing the image scale would outperform the resolution of a shot taken at the prime focus of this 4 inch scope. Looking at images of these objects previously taken with this scope at prime focus, indicate there is a definite improvement.

Had I not had power failure issues with the equipment last night, I would have collected more data and the result would have been much better. I have used the Powermate for planetary before but I have a very nice 2X Barlow lens which I use more often as it fits in the T Adapter with an eyepiece a lot better.
I'm looking forward to planet season!

[LostInSp_ce]

I like Experiments Mick and you're right it does look promising. I've thought about doing this myself in the past but never followed through. It's also a good way to check for any flaws in your setup. Nice one!

[Mickoid (Michael)]

Originally Posted by LostInSp_ce

I like Experiments Mick and you're right it does look promising. I've thought about doing this myself in the past but never followed through. It's also a good way to check for any flaws in your setup. Nice one!

Thanks, and my curiosity on how this would work has been put at rest. I managed a few more subs on this last night but despite the clear sky, the Jetstream was not being nice and my autoguiding at 1375mm and f14 suffered because of it. I found it hard to find a guide star and the ones I chose were moving around and fading in and out causing Phd2 a real headache chasing them. I had to throw a lot of subs away.

The conclusion is, it's doable but really only on a permanent set up and a good one at that. Just setting my rig up in the backyard each night is just too difficult for the effective focal length and focal ratio the Powermate creates. Everything just has to be too precise, so I'll just say "been there, done that" and move on back to where I was before I had this silly idea!

Just for the record: Final submission, M83 20 x 150secs @ 1600iso and M104 14 x 150secs @ 1600iso, modded Canon 550d UVIR cut clip in filter. Don't forget, these were shot using a 4 inch refractor.

[ChrisV (Chris)]

Any focal length over 1m scares me. So I tip my hat to you

Devil's advocate: I wonder how it would compare to what you'd see without the power mate, but using drizzle integration instead? You might get similar resolution and it would be faster?

[RyanJones]

For what it’s worth Micheal, I think your efforts do show promise. No doubt imaging at over 1000mm focal length is hard but the lessons you can learn from trying to, especially with guiding can only make your shorter focal length imaging better. Learning how to fine tune things to get my guiding good enough for round stars with my C9.25 with 0.63 reducer ( 1530mm f/l ) gives me guiding on my 8” f/4 (800 mm) between 0.5 and 0.6 arc seconds. Pretty good I think on a HEQ5 pro with nearly 12kg of scope on it. It does take time though and I know a lot of the time you’d rather be using a clear sky for productive things rather than guide testing.