PDA

View Full Version here: : 305mm reflector - EQ8-R


PKay
29-09-2020, 01:19 PM
Time to have another go, this time on the EQ8-R

I have tried this on the EQ6 but it didn't like it (disaster actually).

At about 20kg, it was quite a task to lift up!

So the moon is out and that is ideal for finding focus.

Details are:
f/l 1524mm.
Aperture: 305mm
Focal Ratio f/5
FOV: 30X40 arcmin
Image Scale: 0.52 arcsec/pix

I have added a EAF to the Crayford focuser, and installed a Baader Rowe Coma Corrector for good measure.
The primary mirror has been re silvered, and the sec. mirror replaced.
Still waiting on a Baader Off Axis Guider, so in the mean time, will try the 60mm guide stuck on the side.

Wish me luck!

jahnpahwa
29-09-2020, 02:00 PM
what a beast!! is that an enlightenenend lightbridge?

Startrek
29-09-2020, 02:09 PM
Peter
My goodness me what a mammoth rig , 20kg ??? My 8” f5 with AP is 15kg, more like 30 to 35kg with AP gear ???
Obviously only for the calmer nights or plenty of tarps strung around
A real Galaxy hunter for sure , faint galaxies too
Can’t wait to see your images
Good luck with it
M

Sunfish
29-09-2020, 02:22 PM
A thing of beauty. I am sure the results will be great.

raymo
29-09-2020, 06:35 PM
The wind shouldn't be much of a problem, with it being on the EQ8, and not
being a solid tube.
raymo

Startrek
29-09-2020, 07:58 PM
Raymo
You would be surprised how wind gusts affect your guiding on long subs , even with this big robust beast of a scope and mount
Steady light wind not much of an issue but medium to strong wind gusts or shifts definitely upset your guiding resulting in bloated or oval shaped stars
My 8” and EQ6-R is no slouch and it’s happened to me on so many occasions I’ve lost count
Hence the comment about the tarps , they have saved many a nights imaging
Cheers
Martin

PKay
30-09-2020, 09:00 AM
The test results came in.

Almost a full moon 20% obscured by cloud. No stars visible.

Rough focus achieved.
All the spacers ended up scattered around the table...

The theoretical image scale was 0.52 arcsec/pixel.

By taking measurements from the image below,
the calculated image scale was 0.55 arcsec/pixel.

Close enough!