TheSkySearchers

The pictures tell the story. Basically I decided to get rid of the secondary mirror and stick the QHY163m camera at prime focus.

The focusing is manual, using a helical focuser. I made it from some spare camera parts with some modifications on a lathe.

You will note that I include pictures of using a laser & barlow combination to do the collimation. Works very well and is easy to do, especially with no secondary to worry about.

Not sure if this is going to work. But here is what it looks like.


BABO

Very interesting .

Should work, but the primary mirror will probably show a lot of coma, maybe use a smaller chip camera?

BTW, I like your mount's latitude setting, almost an alt/az if aimed east/west.

Steve

Is a decent piece of wood or board that hard to come by? If not, it should not be too hard to build a secondary holder. Or did you do it it because you don't have a secondary mirror? Messing with wires and filters in full view of the primary will be problematic.

SkyHiker wrote: ↑Sun Mar 20, 2022 6:15 pm Is a decent piece of wood or board that hard to come by? If not, it should not be too hard to build a secondary holder. Or did you do it it because you don't have a secondary mirror? Messing with wires and filters in full view of the primary will be problematic.

Thanks for your comments, Henk!

I have a 70mm secondary. But it was a cheapie I got on ebay for $30. I made my own spider and holder. Not hard, as you imply.

I did an image of M42 with the old configuration (i.e., using the secondary mirror). That was taken with my Fuji X-A1 (modded).

You can see that image here:

viewtopic.php?f=66&t=23337

Mainly, I just wanted to experiment and see what would it would like to use this new configuration.

The wires are not a problem because they piggyback on the spider vanes.

The filters are not a problem either. I have set up my QHY163m with an internal filter holder (to save on the expense of buying a filter wheel).

It means I have to remove the camera to change filters. But that's true no matter what scope I'm using. So I did not see that as a drawback.

My next post shows a test from last night. It shows the result of a B-mask test and an image of M44.

All in all I was pretty pleased with the result.

Joe BABO

Here's the image I got of M44 with the new configuration (plus a capture of an image of a star using a B-mask).

M44 is B&W since I only used the L filter.

BABO 8in Astrograph using a QHY163m (208-83-25) on EQ-G mount

Processing with DSS / StarTools v1.4 / GIMP

48 x 4s



Joe BABO