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Sharpstar 61 EDPH II APO Chromatic Abberation?

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#151 UKalwayscloudy

UKalwayscloudy

    Mariner 2

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  • Posts: 287
  • Joined: 21 Feb 2019

Posted Yesterday, 08:27 AM

TSRED279 arrived this morning and I have done a crude initial test with some fixed spacers that gave me 74mm Backfocus with my aps-c Hypercam 26c attached. Just been doing some daytime work and am very pleased so far. In particular illumination is flat, to the eye, into the corners so I believe TS claim that it is good to 30mm.

Using the 2in plug fit for now and will see if I can set up a screw fit. Will report back when I've had a chance to play on a proper target.


Edited by UKalwayscloudy, Yesterday, 08:41 AM.


#152 UKalwayscloudy

UKalwayscloudy

    Mariner 2

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  • Posts: 287
  • Joined: 21 Feb 2019

Posted Today, 07:38 AM

TSRED279 update:

 

The M54 thread on the 2in scope plug of the reducer is easily adapted to the M63 thread on the scope with the TS adapter with the rotator built in (the TS part "CAA", which I happened to have from another project), so I now have a secure screw fit with rotation. I did a full frame illumination test on my Nikon Z6 and the results are good - there is the vignetting you might expect from a T2 link but it is really only in the deep corners. Vignetting is minimal to the eye on a 24mm x 24mm square let alone DX or APS-C, so this all come down to the radius at which the correction of star shapes deteriorates. Pic of FX flat frame shown. Just need a clear night now. (Any banding on the pic is just jpeg compression artefacts)

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  • TSFX2.jpg

Edited by UKalwayscloudy, Today, 07:41 AM.



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