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Astro imaging with the new Quad TCC

Started by RolandC, 06/11/2015 08:40PM
Posted 06/11/2015 08:40PM Opening Post
Hi Astro-Geeks

Astro-Physics has designed and now tested a new accessory for wide field imaging with the 130 GT refractor. The new Telecompressor-Corrector operates at 600mm (approx. F4.6), and will cover a 4 degree field with extremely sharp performance from deep red to the far violet. All the individual color images of R,G,B and L will come to the same focus with the same small star sizes.

The compressor is a 4 element design using a high performance ED glass mated with high index Lanthanum crown. This combination preserves the high color correction of the 130GT lens all the way across the spectrum. On a reasonably stable night the star resolution in a 10 minute exposure will be on the order of 1.1 to 1.3 pixels FWHM with the 5.4 micron 8300 chip - for all 3 colors and Luminance.

The attached image shows the field size of the 8300 chip (QSI 683WSG). The 5.4 micron pixel size is ideal for this focal ratio, producing 1.8 arc sec per pixel. This is an LRGB of M13 with 4 x 5 minute exposures. I am somewhat limited here at my observatory test site, right in the middle of a very light polluted suburban shopping district, so I am not able to show any ground breaking images from here. These images are simply to show the potential of this accessory.

The scope that was used is our newest incarnation of the 130GT, now designated as the 130GTX. It sports a 3.5" focuser with Feathertouch fine focus and a new quick attachment system.

Rolando

The full image is at 50% of full resolution.

Attached Image:

RolandC's attachment for post 59467
Posted 06/11/2015 08:45PM #1
This crop is at 100% resolution.

By the way, I have some good news for the 140 TEC owners. I believe this telecompressor will also work very well with that scope, and most probably reduce or eliminate the slight blue defocus of the older lenses. I will be testing this with one of the original 140 scopes in the coming week. The TCC fits onto the 3.5" Feathertouch focuser, the only thing you need is the quick connect adapter that screws right onto the drawtube.

Rolando

Attached Image:

RolandC's attachment for post 149724
Posted 06/15/2015 02:37PM #2
Great photo :-)

~ Charlie Stevenson

8" f/5.7 String Telescope - 1st Scope Build; 2nd Place Stellafane 2016 Optical Award for Newtonians 12.5" and Smaller
10" f/4.5 Newtonian (June 2015) mirror refigured by Optic Wave Labs P-V WaveFront 1/14.24, Strehl Ratio 0.993 (Aug '15)
Criterion RV-6 seems to be circa 1973 (June 2015) [For Sale]
Celestron C8-A XLT (January 2015) [For Sale]
Celestron PowerSeeker 70AZ (Christmas 2014)
Aldrich Astronomical Society member since 2015
http://astro.charleskelleystevenson.com/