ceefna

Hi Alan thanks for your detailed reply. I have been trying to sort this before I head off to Kelling Heath next week for the star camp. Its quite difficult to gauge how far off the spacing is so last night I added another 3.8mm and it seems to have improved the curvature in the right direction but still not enough. The back focus from the reducer is now at 61.8mm???? I have no idea why this should be so far from 55mm? I plate solved the new image on astrometry.net and its now reporting the correct fov 3.09x2.06 deg and 1.16 arcsec per pixle I am having to put the hex focuser back on as I've run out of inward focus on the steeltrack. I will address the tilt when or if I can get the spacing correct, I have thought about putting the asi1600 back on as that worked nicely at 55mm. So do I just keep adding spacers? Is there any formula to working this out or is it trial and error? I need to make new m54 extensions but how big that is the problem american_frame7_Ha_frame7_-10C_600sec_1x1_2021-10-03_011431.fit

Thanks for the replies, I was going off this image that made me think the camera was too close? The flattener does'nt seem to flatten the image at all compared to without it.

just to add I have the same curve without the reducer fitted.

Hi I have an ED127 fcd100 scope with dedicated 3" 0.7x reducer/flattener and am having issues when using my asi6200 full frame camera. The stars are horrible in the corners but is this to be expected with this setup? Looking at my images they sudgest I am too close to the reducer at 55mm? I've made a 1 and 2mm spacers but even at 58mm there is little to no improvement. Is this just the size of the corrected circle or do you think its worth increasing the back focus further? If anyone has this setup working please let me know Many thanks Richard american_frame6_Ha_frame6_-10C_600sec_1x1_2021-09-29_232547.fit

Hi all, Long story but I own a 14” edge scope and have the dedicated 0.7x reducer which doesn’t reduce! In fact it slightly increases focal length to 4078mm. I have tried every back focus setting possible with no improvement. I have a lengthy thread running on cloudy nights and the consensus from the forum and Celestron themselves is “there is a problem with its optics” I bought the reducer used from USA in 2013 and being very green with sct scopes back then thought it was user error and stuck it in a draw for 8 years. it’s obvious out of warranty and the only thing we can come up with it’s marked up wrong and it has 11” internals as the housing is identical size. would anybody preferably local (so I can drop it off) be willing to screw it on their scope and plate solve an image so we can see if it’s reducing? If nobody is local I will pay for return postage if your willing to test it I will buy you a few beers for your time! Cheers Curly

Hi all, I'm having a bit of an issue understanding what maybe wrong with the results i'm getting. The 0.7x reducer is set at 146mm from the end of its rear thread to the camera chip (zwo 1600 pro). But when I plate solve the image its the same field of view as at native F11. Surely even if my back focus was wrong I should see some reduction in F/L This is a plate solve of one sub with the 0.7x reducer fitted, it's binned 2x2 but unless i've calculated it wrong it's still near the F11 native 3900mm focal length? This is at F11 3900mm my imaging train I can't possibly be so far off with my back focus measurements so I would appreciate any ideas you have. cheers ceefna

Hi Adam many thanks for your reply. I have got the 2 Focusers side by side and they have pretty much the same travel. With the ES 3” reducer You get a m68 adapter to screw it straight to the STD hex focuser draw tube. The baader draw tube has a m58 dovetail or a m55 thread so I can easily make a m68 to m55 adapter to screw the reducer on. From what I have read it was not enough inward focus that stopped the early ED127’s achieving focus with the 3” reducer but I can make my steeltrack adapter (m88 dovetail to m130x1) any length I want so the draw tube is in the same place when wound all the way in. I wasn’t sure if I would have an issue at f5.25 with the reducer? Thanks again Ceefna

Hi everyone, I have picked up a used fcd-100 ed127 with the hex-focuser. As I already have a Baader steeltrack RT focuser spare do you think it would work on this scope? Or will it suffer from horrible vignetting with being 2" as apposed to 2.5". Physically they are quite similar in size and the Baader has plenty of focus travel. I am also going to use the 3" 0.7x reducer that came with the scope if that will make a difference to illuminated field? Camera is a zwo 1600 pro 4/3. I would appreciate some insight if you think it's a waste of time before I knock up an adapter on the lathe. Many thanks Ceefer