Tuesday, January 22, 2008

Images of the Tilted ERF experiment

Notice: It's an extremely dangerous experiment, please don't do it.

A plastic cylindrical box is cut by using a cutter roughly, it will not be good in the first cut, but we can always use a good scissor to make it better.

Then the ERF is attached in the most ugly way, a firm and secure attachment is more than the outlook:-

Another angle to show the tilting angle:-

Finally, to put it at work... you can see light leakage, so it's better to cover it, but since that was a cloudy day, it does not affect much:-

A last note is that, this tilting does not help to remove the secondary shadow.


Ken4Optics said...

Have you considered that the reflection may be coming from the inside of the corrector plate?
Whats the results when a normal solr filer is used?

Oldfield said...

After all the testings, I believe that it's the reflection from the blocking filter back to the secondary mirror and then to the visual back again.

Ken4Optics said...

Did you receive my earlier email regards the modifications you did to the PST?
I'm going to do the same and looking for advice/ info. ie removing the etalon from the "black box" and the thread sizes for the adaptors you made.
I was going to use a Lumicon Ha together with a UV/IR filter as the ERF.
BTW does the etalon work when used with a conventional solar filet instead of the ERF??

Oldfield said...

I've replied your email yesterday or even earlier... just wonder if it's lost?

Regular solar filter will not work since they cut too much light.

Ken4Optics said...

No email received, can you resend to kenm.harrison@gmail.com
Would really appreciate your assistance,

Oldfield said...

Strange... anyway, let me repeat here:

1. Solar filter is too strong to be used as ERF

2. I think H-alpha deep sky is good as ERF, use it only on the objective or else it will be too hot

3. No trick to remove the etalon, just try hard, VERY HARD

4. For the thread size, check this entry:-


Finally, don't use your eyes in any experiment like this, use a cheap webcam or similar

Ken4Optics said...

Thanks very much for the info.
When I finally remove the etalon and get the adaptors machined, I'll email you with an update report. And yes, I will be VERY careful with my eyes!!