Tilt within image train question (powermate 5 times)
I have a custom adaptor I use with a couple of my telescopes, I designed it myself and had an engineer friend machine for me. It allows me to use an eyepiece/barlow and camera via a cheap Vixen extension ring set I obtained which fitted nothing I had.
Last night I inserted the 5 times Powermate and did my 2 locking screw up to hold it in place so it wouldn't fall back into my D810 sensor (mirror locked up in live view) but despite the close tolerances when the engineer machined the adapter up I noticed tightening the retaining screws put a slight slant on the Powermate. This in turn I think put a little CA type fringing around a moon image but not the standard colours usually seen in my Achromats.
My adapter, I will machine a ring inside the tube and fit a compression ring type locking system out of a 2"--1.25" adapter I have spare laying around, that may fix my issue but again, I need to get the correct tool to do it or see if I have the tool steel layng around in another old tool I can grind and modify. (it's near solid alloy 60mm OD, not so much a tube, 5-6mm wall thickness and a lot of weight)
I was using an original model Megrez 80mm semi APO telescope (short focal length I can't remember off the top of my head) and I was curious whether this little off axis slant has introduced the colour fringing. I normally get CA free shots through the little Megrez. I just checked the image done the night before with my Player One Neptune and as I mentioned, no CA with any other configuration, I love the little Megrez for that!
I'm going to machine up a new dedicated adapter for the powermate when I get the alloy and a boring bar for the lathe/milling machine.
The first image is a stitch of 2 half images in MS I.C.E. done with Nikon D810 and powermate with the off colour CA I'm talking about and the second image is done through the Neptune with no Powermate and no CA, done the previous night, 300 frames or thereabouts. Same telescope both nights.
EDIT: After looking at my entire image train and the amount of weight hanging off the rear of my Megrez I realised it's beyond the design brief of the little scope and more so, it's focuser. If I use it for imaging in future I'll use it with the Neptune not the much heavier full frame Nikon. Plus I can't stack the larger images on any software I can find without locking my computer up with memory errors. Each image is 103MB and I CAN NOT stack 10 individual frames no matter how much time I spend (I've spent most of the day persisting, I've now given up). The one image I did include done with the D810 is only 2 single frames stitched in I.C.E..
