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Old 13-07-2015, 08:40 PM
DJT (David)
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DJT is offline
 
Join Date: Nov 2011
Location: Sydney
Posts: 1,452
Quote:
Originally Posted by Paul Haese View Post
I agree with everything except the flattener statement.

I found when using a QSI583 on an RC8 there was still visible field curvature. That was nearly 6 years ago. I confess to being pedantic to star shapes though. The RC8 responds well to the Tak 2.7" flattener. It corrects the field nearly perfectly.

I am still investigating a flattener for the RC12 as the 3" one from Telescope Services does not work. It is sitting on my scope right now but it does not correct the field on a 11002 sensor. I have to crop the field to get a half decent field. I might as well have bought a 6303E.
Hi Paul
Thanks, I should probably have qualified that statement given I have only experienced using smaller sensors. I got burnt with a flattener. Got the PP adapters, put it on and whilst flat, I got the most horrendous hot spot plus other artifacts. Good to know about the tak though. If I get a bigger chip then its worth knowing. (actually, remembering as you had it in your write up if I recall)

Added a single sub from tonight, 20 mins in Ha uncropped with a quick stretch in PI. Close enough. ps, the 6303e is a sensitive little devil.

Quote:
Originally Posted by RickS View Post
Hutech have an adapter from the Tak Collimating scope to T-thread. If you search IIS you'll find a couple of threads where I have mentioned it. I don't remember what it costs but it's a lot less than $130. Every little bit helps

Cheers,
Rick.
Good to know, Rick. I remember seeing the thread a while back. Not begrudging the investment made so far as am enjoying the images coming through at the moment. Having said that, am all for the cheaper options. I know of at least one good imager who just used a standard cheshire on hers. Unbelievable how quickly it adds up though


Quote:
Originally Posted by lazjen View Post
A good write up, thanks for sharing.

I'm not sure how much of your experience can translate to GSO RC10CF, but I can confirm several of your statements, including:

* switching to a different focuser - I did Moonlite as well

* I've had issues with a flattener exactly as you mention. I think it's also occurred with a reducer as well, but I'd have to verify that to be sure.

* I agree with the weight issue, but I've managed to get by, I think it helped that I added a dew shield to the top that added weight. I've also got a small weight on the scope's top bar that I can slide back and forth for finer weight adjustments. It could also be that the larger RC10 has the balance point in a different spot.

* I haven't got a dew heater yet although I've had some problems with dew in the past. The dew shield however seemed to reduce those a lot.

* As far as I can tell, I haven't had any issue with tilt in the system and I haven't done any collimation yet. Now that I'm getting the observatory setup and a permanent install, I can check and investigate this further.
Cheers. Pretty certain the cause of mine was around the connection between the extension tubes and the focuser.
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Last edited by DJT; 14-07-2015 at 05:48 AM.
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