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philjay

An f4.5 ED80 ?

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philjay

A little project Ive been planning since I got the ED80.

I saw the Altair 0.6 reducer flatteners awhile back and that started the thought process off so at the IAS I got one. It quickly became evident that theres not enough back focus on the ed80 stock focuser so using that was out.
I didn't want to chop 3 inches off the tube and reduce the scope resale value so I dug around and found my old Meade 127 focuser which is decidedly shorter in the body and together with a new philjay special design of adapter and rotator this could be made even shorter.

So once the ali was sorted I made a start and the test run was today in daylight with both the Atik and 1000d. The 1000d was easy with just a 10mm spacer between reducer and camera, it reached focus on a distant tree with about 1.4" draw tube extension.

The Atik was a bit more complicated so required a good 40mm spacers to get the correct reducer to chip distance but this was easy enough as I have lots of spacers. I now have a single spacer in place instead of the multiple ones shown, it now looks a bit more elegant

So heres a few snaps of the project, including a screen shot of the distant tree with the Atik

The focuser is compact and rotates by unlocking the screw shown, rotating and then locking. I'm quite proud of that design :D 

All I need to do now is test it under the stars. I'm not sure of the effectiveness of this as it's rather quiet in tinternet land about these 0.6x reducer flatteners, either that's because they are not that great or because they need so much back focus that folks give up or don't bother.
So watch this space :)

Edited by philjay

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philjay

If it aint up to much I haven't lost owt, I can put the original focuser back on and all Ive lost is a couple of hours on the lathe, which I don't mind a bit :D  :D


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philjay

Managed 1st light last night for about 10 minutes through gaps in cloud, I had cocked the spacing up with the Atik, it seems its 55mm from the back of the reducer body not the rear element. Only twigged that when messing with the 1000d which has 44mm back focus and works with a 10mm spacer on these reducers. The website could do with clarifying that.

So by the time I had twigged the correct spacers for the atik it was cloudy all over, still I proved the focuser mod worked a trest

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philjay

Last night I had a good play with the modded ED80 and the focuser and rotator mod worked superbly.


 


However the reducer I cannot get on with. I have now tried umpteen different spacings and cannot get a useable image with it, that's with both the Atik and 1000d.


 


The AA web page states 55mm spacing so


with the Canon having 44mm back focus to chip that's 11mm spacer right? No chance there is only 30% useable fov in the centre.


with the Atik I made a spacer to get the 55mm and again no chance, comet like stars all over the place.


 


I have tried making spacers so that its 55mm from the rear element of the reducer instead of the back and still no joy, worse in actual fact. So Im stumped now. Gonna ask AA next I reckon


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philjay

Tried pming AA and emailing direct this last week and no reply. So Ive just tried the AA web page contact form, lets see if I get a response.

Thinking Ive got a lemon here with this reducer

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philjay

Its the spacing between the reducer and camera chip Ron. I have no problems focusing due to the focuser mod.

Getting the spacing between the chip and reducer is critical to getting a flat field. Either side of this and you get wierd shaped stars in various degrees, I used to have lots of fun with my old WO adjustable flattener. AA advertise this as a reducer/flattener, so far it just reduces

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philjay

Its been awhile since I started this mod, focuser mod has been fine but I eventually gave up for awhile getting the spacers between the reducer and chip on the Atik 314

Ive been feeling a bit like my old self these past few days so revisited it and made up a combo of M42 spacers and filter wheel to get what I reckon should be close to the stated 55mm spacing.

 

Initial tests on IC1848 last night showed poor flat field so I rearranged a few spacers and this was the best I could get with the spacers at my disposal. There s a lot of strange stars in there but its close.

 

Focus was difficult possibly due to spacers not right?? But Its a nice wide field though and the f4.5 certainly pulls the photons in. Not much in the processing of this 2 hour image but its enough to show it may work with a bit more tinkering.

 

 

I have got some 55mm ali round bar and have been practicing my screw cutting on the lathe so I am going to attempt an adjustable spacer now I know that I am close. 

1848.jpg

Edited by philjay

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philjay

Cheers Pete & Steve
Yeah Im pleased with the fov on the Atik, I think it may be pushing the reducer for flatness with my canon 1000d aps c sensor but I will try that later, concentrating on the smaller atik chip at the mo

Sent from my GT-P3110 using Tapatalk

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philjay

OK so progress so far, adjustable t2 adapter worked a treat (see other thread). Set up the specified distances with vernia to as accurate as I could and lobbed the scope on auto for 90 minutes, whilst I sat in the warm watching telly and came back to this after 90 minutes. It isn't very often you get to be able to leave the rig for such a long time without getting clouded out and losing guiding.

 

This is a test of 90 minutes worth of 5 minute subs and its no where near, awful blobby comet type stars everywhere and centre stars not small enough. But its picked up tons of nebulae. I processed it to see what it would do.

 

I then did a bit of adjustment and the M42 is about the best I can get so far. Single 5 minute sub. Its better but still not right with poor stars away from centre.

I love the FOV but cannot seem to get tight stars with it. Perhaps Im asking too much of a 70 quid reducer, maybe maybe not. I shall give it a couple more tries when I get the enthusiasm up for it but Im doing visual tonight if its clear as forecast :D

m45reducertest.jpg

m42redtest5min.jpg

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