QHY5L-II mono + Orion ST-80 Ext Tubes

[kkara4 (Krishan)]

Originally Posted by gbeal

I won't get into the guide-scope Vs OAG debate, each has their respective merits. Plus I currently use a guide-scope, but have in the past also used an OAG.

I'd run a few numbers though before making a broad statement about costs. What did the Orion ST80 cost? A decent OAG can be about the $100+ used, up to serious money.
If you are going to use an SCT, the OAG "might" be better.
Now you have the ST80, keep trying of course, but if you see an OAG in the Buy/Sell section, give it some thought.
Gary

Very true, cheers Gary!

[kkara4 (Krishan)]

so at the moment the sensor would actually be right around flush with the extension tube opening if I didnt use the filter attachment, and had the draw tube fully racked out for the in-focus point.

Extension tube ordered anyway, so will be perfect with a second one, then I can have the draw tube about half way along its travel, and the camera inserted into the extension tube properly

Settings of gain 25, exposure 0.5ms and gamma default for firecapture seem to be great for daytime use of dark coloured trees.

[Camelopardalis (Dunk)]

How are you connecting the guide cam to the ST80?

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

How are you connecting the guide cam to the ST80?

Dunk, here is a picture. Excuse the books, jumper and various other unrelated stuff .

That picture is taken when cam was in focus, and you can see why I needed the 1.25" filter adapter threaded on (else there would be nothing to secure it in the extension tube).

[Camelopardalis (Dunk)]

Something's not right...although I can't tell what...a 1.25" visual shouldn't struggle to reach focus on an ST80...it's their territory!

Incidentally, when attempting to find an object to focus on, I use very high gain (like approaching 100) and 50ms or so exposure times.

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

Something's not right...although I can't tell what...a 1.25" visual shouldn't struggle to reach focus on an ST80...it's their territory!

hmm, well I measured 400mm back from the front lens (roughly) and it coincides roughly at the camera sensor position shown in the picture.

but unless more people who know the ST80 well can provide some insight, have to deal with it

[Camelopardalis (Dunk)]

Have you tried it with a diagonal?

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

Have you tried it with a diagonal?

nah dont have one, and in any case that would extend it right about to where i have it in the picture i think.

i only bought the OTA