First light (at long last)

Dave882 (David) · #1 09-02-2022, 02:24 PM

Well after finally succumbing to a severe case of aperture fever I managed to pick up an older c14 2nd hand in the new year (planning to use it for planetary imaging) but couldn’t wait to see how it would go under the stars now!! It’s sitting on an eq8 (older version) and tube rings.

Got a few hours out last night and with lots of fiddling to try and get the backspacing for the reducer right (still not right) but got a few quick shots off anyways. B6/7 suburbs so had to employ the UHC filter - all with the asi294mc pro and some basic tweaks in PSexpress.

NGC5728 - 6x 300sec
M65 - 60x 60sec (crop)

All taken with 0.63x reducer. Guiding was with oag at ~2400mm and asi290mm. Figures were quite exceptional actually (rms typical between 0.5-0.7) but some questionable looking stars with some spacing/tilt issues and maybe a bit of flexure or slip in the rings. I mean who doesn’t enjoy trouble shooting camera spacing/tilt issues

Hope all my fellow Sydney-siders can enjoy a few moments of clear sky while it lasts…

Graman (GR) · #2 09-02-2022, 04:27 PM

Those are amazing shots...esp. from light-polluted Sydney!

Some nice details and "depth" in both images...can't wait to see what else the C14 produces...

Mickoid (Michael) · #3 09-02-2022, 05:27 PM

A great start David. Very promising, especially when you can get these results with such short exposures. Like GR said, can't wait to see what you can achieve with this set up with more data from longer integration times.

Kuz · #4 09-02-2022, 05:31 PM

Nice effort Dave . I personally like the middle image. Always reminds me of coke a cola shooting out the top of a bottle. Looking forward to your next images with the c14 . They look like a sweet online. Yet to see one in real life

Stephane · #5 09-02-2022, 10:21 PM

Two gorgeous images there. Especially considering they were both collected on a single night! Nice job.

Dave882 (David) · #6 10-02-2022, 10:58 AM

Thanks guys I really appreciate the comments! The c14 is pulling in 3x the light of my c8 so there is a certainly a time advantage when imaging small or dim targets. This is of course all for nothing if the image isnt tight or you can’t maintain guiding accuracy. I’m quite happy with this first light and hopefully if I can work out the spacing and flexure it’ll be even better. I’ve attempted these targets before and even with extended integration times was not able to get the detail/resolution so happy to get this deep from the suburbs.

I tried a couple of nebula targets (see Orion attached from the same night) as well and honestly couldn’t see too much advantage of using this beast for a target like this, but an interesting exercise nonetheless.

One thing I did notice was that imaging towards the Sydney cbd light glow was very challenging and even with the UHC in place was forced to reduce the length of the subs a lot.

evltoy (Wayne) · #7 10-02-2022, 11:06 AM

Those images are awesome! I would be stoked with that.

I also saw the guiding total of .33". Thats very very impressive for a mount holding a c14 and your setup has a Res of .39"/pixel... bang on.

You must have very good clear skies for the res setup.

One question though. Is it recommended to use a UHC filter on Galaxies? I was told not to and to either use nothing (in you case cant due to B6/7) or to use a CLS or Moon/Sky Glow filter.

Interested to see more images in the future.

Cheers
Wayne

Dave882 (David) · #8 10-02-2022, 11:50 AM

Hi Wayne- thanks for the comments. Yes I was surprised by the guiding as well - it wasn’t always as good as the pic but on average between 0.5-0.7 which certainly exceeded my expectations. I was out again last night as well and must have been bit more unstable and was only around the 0.7-0.9 mark. Ive never really binned before but maybe I’ll need to 2x bin the 294mc pro?

To answer your question about the UHC- yes I would recommend using something like uv/ir but to shoot m65 I was pointing low and right at the Sydney light dome and I remembered last time I tried that I had terrible gradients. I figured with 14” aperture I could get enough light to overcome the filter but you can see that the colours are off as a result.

Anyways- it’s all still a work in progress. My setup for taking flats was hilarious when I realised my el panel was too small- a big white towel on the ground with the outdoor lights blazing and my scope doing a handstand pointing at the towel

But it kinda worked…

evltoy (Wayne) · #9 10-02-2022, 01:21 PM

lol. The joys of taking flats with a large scope or with hyper-star.. it would have been funny to see. And thanks for point that out as I only have an A3 el panel.... something to think about if I get a larger SCT.

I'm just about to start using my 8" SCT for the next few months in a B5 area. Will give the UHC filter a try on Galaxies.

Keep the images rolling through

Dave882 (David) · #10 10-02-2022, 02:32 PM

Quote:

Originally Posted by evltoy

lol. The joys of taking flats with a large scope or with hyper-star.. it would have been funny to see. And thanks for point that out as I only have an A3 el panel.... something to think about if I get a larger SCT.

I'm just about to start using my 8" SCT for the next few months in a B5 area. Will give the UHC filter a try on Galaxies.

Keep the images rolling through

Hi Wayne- in B5 and using a c8 I’d stick with the uv/ir filter on galaxies. I reckon the UHC will be too much reduction in transmission. By all means give it a shot but I don’t think you’ll like the result imho

Yes I look forward to some more DSO action with the c14 if La Lina ever let’s up. I had another go last night but my attempted adjustment for tilt ended up making things twice as bad. I did get 45min on the Eskimo Nebula with an L-extreme filter that was half decent (after a heavy crop)