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A few months back, i bought my first mono camera, an Atik 383l+ from Martin @Xsubmariner off here. I hadn't had a chance to give it a whirl until last night.
I thought about getting the 80ED out, but i've been wanting to do some widefield stuff for a while, so i attached an old Tamron 135mm F2.8 vintage M42 lens i picked up last year for next to nothing. The lens needs to be stopped down to F5.6 (perhaps less, i haven't tested though) to produce acceptable stars in broadband, but i was hoping it could be used more wide open for Narrowband. I used step-down rings screwed on to the end of the lens hood to bring the aperture down to 37mm, which is about F3.65 (i did briefly try it wide open in Ha, and it wasn't that bad tbh, but i could still make out some comet-shaped stars in a few places so i opted to stop it down a bit to play it safe). I have a TS Optics filter drawer in the optical train, so i can still swap out filters without too much fuss. I still have about 3-4mm of extra backfocus space to spare, but i can already find focus as it is, so i'm not sure if it's that important that i haven't fully used it all up.
Focusing was tough. I was focusing using a Bahtinov mask on Deneb, and i had to use 10s subs (subframes) at 2x2 bin to get bright enough spikes for Bahtinov Grabber to pick up to the spikes ok. Even then, it was showing the focus error moving about quite a bit, even without me touching the focus ring. In the end i just got it as close as i could and went with it.
Conditions were not great. Some clear spells, but there was a lot of cloud passing through. I figures it would be good enough for a test session. The Phd guide graph looked horrific, and was somewhere in the 1-2" range (image scale is 8.4" so not a big deal hopefully). I bodged together a couple of old dovetails to add enough weight to counter-balance the 5Kg counterweight. It just about does. It's not perfect by any means, but hopefully sufficient for this purpose.
I would ideally like to shoot 1200s subs, but couldn't last night due to the constant clouds (Phd lost the guide star countless times). I was about to give up, but persisted and aimed for 600s subs. Glad i did, as i ended up with 6 useable subs, even if a couple were affected by some thin cloud.
Did a quick stack in APP and a 10 min process in PS, just to get a rough idea of what i can expect from this. I used Flats and a couple of Darks just to do a rough calibration. Didn't do any gradient reduction, was in too much of a hurry after packing up last night. Overall i'm fairly pleased with how it performed. I'm obviously not aiming for Samyang 135mm F2 levels of performance here, but for purely NB bi-colour mosaics i think it can do a job.
I've included a picture of the rig below as well, in case anyone's interested.
6 x 600s (1 Hr)
Atik 383l+ 2" Baader Ha 7nm
Tamron Adaptall2 135mm F2.8 (@F3.65)
My effort from Derry last night - once I remembered to remove the cover from the field flattener. Doh.
I know the North America Nebula is done to death, but this is my first time imaging it, and also my first time trying the Triad filter with my Nikon. I'm in the middle of the city but I was able to take 5 min subs! I processed in PixInsight, but didn't even have to do background extraction. I used photometric colour calibration to restore natural colour and then just did a bit of mild tinkering. I'm impressed by the Triad filter on my first try.
Comments welcome - maybe I should try a star mask and try to bring out star colours?
22 X 5 min subs - 1hr 50min integration
PixInsight for calibration / registration / processing
Mount - Vixen AXD2
Scope - TEC 180FL
Camera - Nikon D750
I'm still transitioning from an unmodified Canon 200D to an Altair Astro 183C pro. I think this might be my best image yet, and the first time I have tried a mosaic.
Its made of two panels, each panel has 20x120s + 30x60s. Stacked and stitched in Astro Pixel Processor and edited in PS CC 2018. I'm pretty pleased!
Scope is a SW ED80 DS pro (reduced to 480mm, f/6) on a HEQ5 pro. Guided with a QHY5L-II in my finderscope.