Micromega Critical Focuser

**SAShruby** · 17-Jul-2007, 16:50

Hi all,

I recently purchased Micromega critical focuser and I found out that mirror is quite schratched. B&H Photo has replacement mirror for Peak 1. Are they compatible?
Somewhere I red that Micromega is actually Peak. Is that correct?

Thanks.

**R Mann** · 18-Jul-2007, 01:35

Yes, they are the same. All you need is a front surface mirror - which you may be able to get for less than the B&H replacement.

**John Barnholtz** · 18-Jul-2007, 05:20

Try here for a replacement mirror orderdesk@fsmirrors.com.
The cost was (3.5" x 1.125" x 6mm STANDARD first surface mirrors: $16.00) plus shipping. I bought a spare also.
Good luck
John

**Robert Ley** · 18-Jul-2007, 05:37

Peter,
I have a Micromega focuser as well and the mirror is well scratched. I have never really noticed it when looking in the eye piece. I have been using it for several years with good results. Is yours so scratched that it is noticeable in the eye piece? When I focus on the grain, I can't see the mirror scratches. I bought it used and it came pre-scratched, so I have never experienced a new mirror. Is there a huge difference? Please, someone enlighten me.
Robert

**SAShruby** · 18-Jul-2007, 09:41

John,

Thanks for the info, I'm surprised that thickness of the glass is 6mm. Can you confirm that?

Thanks for your inputs to you all.

**Alan Rabe** · 18-Jul-2007, 14:26

Since your actually focusing thru the mirror instead of on it, it is like focusing thru a chain link fence the fence and scratches just disappear as they are not being focused on. I have one it has a itty-bitty scuff on it and it never comes into play. Although I can't really understand how one scratces these things. They have a hinged cover that makes them almost bullet proof. People must clean them with steel wool or something.

**ronald moravec** · 17-Aug-2007, 13:49

The proper thickness is important as you are focusing on the top of the glass. The top of the glass or mirror surface distance to the base is critical to the image being in focus after critical focusing. If you change this dimension with the wrong thickness glass, your neg will not be in focus but the critical focuser will be.