5 replies to this topic

[AstroFritz_]

Hi,

 

I'm thinking about buying an Esprit 100 with the 0.65 Apex reducer by Starizona.

I'm using a color camera with dual narrowband filters in a filter drawer.

 

The Esprit, in combination with the Apex, is a really fast system (f/3.6).

Do I need to adjust the backfocus when using a filter?

 

I know that filters change the backfocus, but is that noticeable in this system?

 

At the moment, I'm using an FRA300 by Askar. It's a flat-field design, so I only need to refocus, and everything works fine.

 

I would appreciate your help!

 

 

Best regards,
Brian

[Jason B]

I use the Apex "L" with dual and tri band filters down to F4.5 with my AT111 and an ASI533.  I set the spacing to 55mm per the Apex instructions and had no issues.  Granted, my camera has a smaller sensor but I also did this with my 294 without issues as well.  Just slight refocus between dual and tri band filters.   

[AstroFritz_]

Hi Jason,

 

thanks for your reply.

 

I think that the problem is that the Esprit 100 iwth the Apex has F3.6 and that togather with the APSC sized cam could be difficult.

 

Maybe here is some one arround with an Apex on the Esprit 100.

[honyi]

Hi Jason,

 

thanks for your reply.

 

I think that the problem is that the Esprit 100 iwth the Apex has F3.6 and that togather with the APSC sized cam could be difficult.

 

Maybe here is some one arround with an Apex on the Esprit 100.

I am using the Esprit 100 with Apex-L and ASI2600MC pro combination.

 

The backspacing will be affected if you put a filter between the camera and the reducer. You need to increase the backspacing by 1/3 of the glass thickness of the filter.

 

I get around this issue of constantly changing spacing if I use a different filter, by screwing the filter to the M48 threads on the Apex. So the filter goes between the scope and the reducer. In that way i have a few advantages (1) I do not need to change the spacing between the camera and the reducer; and (2) I do not need to get high speed filters (which are recommended for something as fast as f3.6). This is because the filters "see" f5.5, and not f3.6

[AstroFritz_]

I am using the Esprit 100 with Apex-L and ASI2600MC pro combination.

 

The backspacing will be affected if you put a filter between the camera and the reducer. You need to increase the backspacing by 1/3 of the glass thickness of the filter.

 

I get around this issue of constantly changing spacing if I use a different filter, by screwing the filter to the M48 threads on the Apex. So the filter goes between the scope and the reducer. In that way i have a few advantages (1) I do not need to change the spacing between the camera and the reducer; and (2) I do not need to get high speed filters (which are recommended for something as fast as f3.6). This is because the filters "see" f5.5, and not f3.6

That sounds really good!

Can you post a picture of how you attached everything.

There is an adapter out for the Esprit. I think you use and differnt adpater right?

 

At the moment Im thinking of the Esprit 100 + Apex but also of the new SQA85 from Askar.
I think the Askar would be more easy to use because of the flatfield design.
Also the Askar has really small stars.

But the Esprit is fast.

I have to think about that

[honyi]

That sounds really good!

Can you post a picture of how you attached everything.

There is an adapter out for the Esprit. I think you use and differnt adpater right?

 

At the moment Im thinking of the Esprit 100 + Apex but also of the new SQA85 from Askar.
I think the Askar would be more easy to use because of the flatfield design.
Also the Askar has really small stars.

But the Esprit is fast.

I have to think about that

Sorry, took me a while to get back because i was caught up with work.

 

 

To attach the rotator to the M74 thread of the Esprit 100 focuser, I use a M74F to M72F adapter (since the rotator has M72 threads).

I also have a M72M adapter which has 2 threads - M42F internal thread to screw the Apex into, and M48 thread for the camera side.

The silver cap is a screw on M48 cap which i use to prevent dust from getting into the imaging train when the cam is not fitted on.

 

 

This is how it looks when all fitted into the Esprit 100 focuser

 

 

With my camera adapter fitted and ready to fit on the ASI2600mc

Edited by honyi, 23 October 2024 - 09:04 AM.