Hi all ...

Using eyepiece projection with my 8 inch F10 LX200 and the
Meade Variable Projection adapter and any of the eyepieces I
have whether they be Meade Super Plossls at 26 or 12.4 mm or
UO Orthoscopic ep at 12 mm I get a flare in the middle of
the frame . I had played around with flocked black paper
etc etc inside the eypieces at the shiny filter threads and
inside the projection adapter etc but nothing seemed to
change .

Recently I have been playing with a little Kensington Super
Vga Pc Cam (without its lens) and find that lo and behold ,
I see the same flare , but only with the projection adapter
, not with Barlows Meade 140 or the Televue 5X Powermate
I know this is too much power but it has been interesting
.. I can easily image a ruler with 1/100 inch markings
across the backyard at 60 feet... and also image a 1 ,2 and
3 mil line on a B&L reticle , although with less contrast
than the ruler-have not decided yet if thats optics or
lighting of the chrome lines on the reticle) ..


With the camera , I can watch things almost real time as I
move things around , and it looks like there is some sort of
fundamental limitation of the distance between the eyepiece
and the sensor . If you just look into the eyepiece visually
beyond its first image ... say 2 or 3 inches , I can see
what appears to be the primary mirror with the dark spot of
the secondary in the center . Obviously as you get closer to
the eyepiece , you then do not see that mirror image but the
"real" image.

So my question is " Is the mirror image I see an image that
the camera or sensor should see just as I do visually ? "
This may be a really dumb question but I am not an optical
guru)

It appears to me that is the source of the "flare " I get in
the center of the frame in 35 mm stuff or with the cmos
sensor.

I have Covingtons' book and some other sources that discuss
calculating effective focal length numbers for eyepiece
projection etc but none seem to address any limitation of
distance from eyepiece to sensor (film or ccd etc) .. I know
there are practical limitations on the amount of
magnification I can try to achieve but I see the flare long
before I am at that sort of limit.

Incidentally this flare is just seen on bright objects like
the moon , sun etc.

Comments anybody ? Please excuse the lengthy post but I
felt I needed to describe the conditions.

If I should try some other forum , let me know .which one, I
seldom look at anything except MAPUG.

Rgds... Hank.

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