Meade field derotator

JY · Post by JY » Tue Jun 01, 2004 8:46 am

Hi,

I started imaging in Singapore in alt-az mode with a LX200 12".
One minute images with a SBIG ST8 are fine.
I took up to 60 images, 1 minute each and then rotated and combined them (using CCDSoft). It is a bit tiring but it works fine.

This M101 was imaged using this setup : http://www.geocities.com/jybeninger/dee ... 030330.jpg

I then purchased a used field derotator on Astromart. It took me one year to make it work.
The final problem was software related. I contacted Meade, sent them my observations and they finally solved it in Autostar II version 1.7i .

Now that it works, I see no rotation whatsoever with 10 minutes images. In stacks of several such shots, I have no rotation as well.

If you want to see how it looks inside and how it works :
http://www.geocities.com/jybeninger/derot.html
Cheers

Jean-Yves

tanguan2001 · Post by **tanguan2001** » Tue Jun 01, 2004 7:03 pm

Thanks for the info, Jean-Yves.

TG

Post by **Airconvent** » Wed Jun 02, 2004 12:23 am

Hi Jean-Yves,
You look like a very competent technical guy...ever thought of running a repair and "super charging" (like Dr Clay) service in Singapore?

rich

JY · Post by JY » Wed Jun 02, 2004 11:01 am

Hi Rich,

Thanks for the kind comment : in fact, I had my LX200 supercharged by Dr Clay himself...

With the often cloudy weather, I think I have spent more time twicking the inside of my stuff than looking through it !

I would be glad to help if anyone here has some tech problem ... reminds me that I promised Chris to check his mirror lock ... Chris, are you in town this week ? (you can email me at jy"at"lesbeninger.com )

Cheers

Jean-Yves

shoelevy · Post by **shoelevy** » Wed Jun 02, 2004 11:07 am

Is the rotation you talked about related to the fact that your mount is an alt azi mount (rotation absent in GEM) ?
Anyway...looking at your first post...i was just wondering how much did you spend on the meade and the ST8?

JY · Post by JY » Wed Jun 02, 2004 12:03 pm

Correct, the rotation I talk about is absent in GEM.

Cheers

Jean-Yves

shoelevy · Post by **shoelevy** » Wed Jun 02, 2004 4:48 pm

wah!
u've a hell lot of money to spend don't u
your passion is admirable

could u comment of the performance of the ST8?
cos i'm currently seeking out a ccd

and wat laptop r u using to control the st8?

JY · Post by JY » Wed Jun 02, 2004 7:03 pm

Don't worry, in twenty years time I am sure you'll have a better setting if you keep the passion !

The ST8 is a very good CCD : lots of small pixels !
Even at bin 2x2, the resolution is very good and the image size is still decent.
It captures the faintest light and I get down to magnitude 16 in one minute shots here, in Singapore...

I chose the model NABG (non anti blooming) : you can determine the magnitude of stars with these models and do some science projects.

Buy it on Astromart, and if you want to change it, you can sell it at the same price.

I am using a four years old Acer laptop, normal specs, nothing extraordinary.

Cheers

Jean-Yves

shoelevy · Post by **shoelevy** » Wed Jun 02, 2004 9:52 pm

non antibloom?....doesn't that mean that if the target has bright stars close by you'll have problems with those stars?

MAGNITUDE 16 in spore?!?! fantastic i must see

JY · Post by JY » Thu Jun 03, 2004 8:38 am

Yes, NABG can create problems with bright stars.
You then have to take shorter exposure images and stack them or use a "deblooming" tool which is a paint brush tool ... only for cosmetics.

A few 16 and 17 mag supernovae imaged from Yo Chu Kang last year : http://www.geocities.com/jybeninger/supernova.html