Takahashi FC-100DC debut (and diagonal problem)

[John]

A Powermate, TeleXtender or Focal Extender (Tele Vue, Meade and ES products) move the focus point either not at all or very little.

[PGM]

3 hours ago, Nakedgun said:

The short-throw focuser on the DC can make finding the right combination a trying experience. Diagonals from different manufacturers will not all have the same focal length, nor will all barlows. I found this shorty barlow to be helpful. To use a "regular" length barlow I have to change extension combos.  An observing associate with a variety of ep/barlow/diagonal choices can save some time and aggravation.

 

 

 

Absolutely! My barlow is also a shorty (Celestron X-Cel ED Barlow 2x) but I had no luck with it. Unfortunately where I live I know nobody pursuing visual astronomy who could help, and I can't keep buying more and more equipment just to try it once and resell it.

[PGM]

2 minutes ago, John said:

A Powermate, TeleXtender or Focal Extender (Tele Vue, Meade and ES products) move the focus point either not at all or very little.

That's interesting, I didn't know that. I might buy a 2.5x Powermate to try it then.

[godra]

HI!

Can I reach focus with most 1.25" eyepieces if i buy Baader T2 BBHS diagonal? I have FC100DC with all adapters except n›16 - TKP20001(for staight through viewing)

Edited January 26, 2021 by godra

[Highburymark]

On 26/01/2021 at 14:12, godra said:

HI!

Can I reach focus with most 1.25" eyepieces if i buy Baader T2 BBHS diagonal? I have FC100DC with all adapters except n›16 - TKP20001(for staight through viewing)

One option if you go for the T2 diagonal is to use just T2 spacers to reach focus. As you see in the attached photo I removed the green Tak spacer element between the OTA and the focuser (it just unscrews) and now can reach focus with binoviewer and all ep combinations, Quark, or in normal night mode with single 1.25” or 2” eps - all I do is change the number of T2 spacers.

[godra]

On 27.1.2021. at 18:51, Highburymark said:

One option if you go for the T2 diagonal is to use just T2 spacers to reach focus. As you see in the attached photo I removed the green Tak spacer element between the OTA and the focuser (it just unscrews) and now can reach focus with binoviewer and all ep combinations, Quark, or in normal night mode with single 1.25” or 2” eps - all I do is change the number of T2 spacers.

Thank you!

I can see your diagonal is one of the Baader T2.  And also I can see that there's no clear consensus is the prism better than BBHS for this F number(7.4) Which one you prefer better?

Edited January 31, 2021 by godra

[Highburymark]

On 31/01/2021 at 16:05, godra said:

Thank you!

I can see your diagonal is one of the Baader T2.  And also I can see that there's no clear consensus is the prism better than BBHS for this F number(7.4) Which one you prefer better?

I can’t see a difference to be honest. I use the prism with my solar Ha scope as I need the short light path to reach focus, and BBHS mirrors for other viewing