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View Full Version here: : M 27 utilizing a new brand of airspaced triple apo


Dietmar
02-08-2009, 10:12 PM
hi guys,


I am getting back here after a long pause, due to various reasons.
more than half of the year has passed without imaging, I am afraid...

APM and TS asked me to test a new brand of air spaced triple apo,
which comprise a TS-focuser.
this scope is 4 inch f/6.5 triple apo, housing lenses NOT being
designed by TMB and NOT manufactured by LZOS.
still, visually the apo displays stars pin point like, though there is
a difference that is noticable to any experienced TMB guy like me...
anyway, it is a keen instrument for both purposes, visual observation
and photography.

I tested the f/6.5 scope with my H16 (15x15mm; 7.4 micron), and it is
mandatory to use a flattener, which was also provided for the tests.
the focuser is very handy and stable enough for visual purposes and
light weigth photo-equipment I am sure (OSC)
but in the case of using a flattener, a filter wheel (FLI 7 slot) and
a CCD this focuser is overbeared I am afraid, as you can tell by the
distorted stars in the top right corner...(see full size version)
nevertheless, the scope is relatively cheap and makes a good
instrument for people shopping for a fast small apo.

so, this image renders a FL result of this nice scope.
find all data on my website:
http://www.stargazer-observatory.com/M27-4.html
make sure to see the full size version as well.
thanks for looking!

renormalised
02-08-2009, 10:20 PM
Great to see you back, Dietz:D:D

Yep, you can see the ovalish stars in that corner of the piccie...slight, but it's there. Needs a beefier focuser.....grab a Feathertouch.

Dietmar
02-08-2009, 10:25 PM
thanks Carl!
I sure noticed the tilt-rpblem all the way through imaging. and I tried a couple things.
I recommended the companies to change for a more stable focuser.
but the image was to test the entire system they want to provide on the market.

renormalised
02-08-2009, 10:32 PM
If someone was going to use a big CCD, and had filter wheels etc, they'd probably replace the focuser anyway.

Hagar
03-08-2009, 04:00 PM
Very nice Dietmar, The scope seems to have resolved the detail and the outer detail very nicely. I have never seen this outer detail before and would be a bit concerned that it is partially a reflection in the lensing system. If not it has performed very nicely.

Alchemy
03-08-2009, 07:04 PM
i also have not seen so much detail in the outer shell, i was aware of one jet but hadnt seen four previously... thats what it looks like.

its always nice to be suprised.

clive

AlexN
03-08-2009, 09:48 PM
Definitely a promising result.. Did APM mention why they had changed lens manufacturers from TMB/LZOS to something different? I would imagine price has something to do with it, as a 4" F/6.5 TMB designed LZOS built lens surely wouldn't be cheap!

I must say, the image looks nice but its not a scratch on the result you obtained with your TMB 9" APO...

Good to see you back on the forums Dietz..

Alex.