PST Mod: Blocking Filters

[misterp]

Hi,

I have just completed a stage 2 mod of my PST with a Celestron 80mm firstscope and a 75mm DERF - very impressed so far

Thanks to Ken for his word document and other posters here.

What is the difference between Lunt blocking filters and the Coronado ones please?

Thanks

Ian

[Merlin66]

They both seem to work well with the PST etalon, so which ever you can find would be OK.

[Peter Drew]

Also the Lunt blocking filters are 2" fit compared to 1.25" on the Coronado.

[misterp]

Are there potential problems with rust on the Coronado ones ?

Also apart from the cost is it there any reason why you wouldn't get one which is designed for a longer focal length than you have?

Finally, the Lunt 1200 is designed for focal lengths of upto 1080mm, is this critical for full disk view as my donor scope is 1100mm?

Thanks again

Ian

[Merlin66]

No rust problems on current build filters.

A Lunt 1200 has a 12mm filter which would be OK up to 1200mm focal length.

The larger filter gives a larger FOV with low powered eyepieces.

[Peter Drew]

I use a 80mm PST mod with 1100mm FL, I can get 2/3 of the solar disk with a 5mm BF so a 12mm should be adequate for a full Sun.

[Ransu]

Has anyone here tried Lunt BF1200 with PST mod parts? Any problems mixing them?

I got yesterday good first light with my PST/TAL100RS Solaris/90mm D-ERF mod.

(some images in my blog) Otherwise i got amazing views, but original BF5 blocks visually quite a lot of solar disc. I have looked for Coronado BF10 or BF15, not many dealers in Europe i suppose, and even BF10 price seems to be very high. APM telescopes have coronado bf10 and Lunt bf 1200, which seems to cheaper.

What you think, would it be ok with my other parts.

And thousand thanks for Merlin66 and others about all information you have shared.

[Merlin66]

Yes, the Lunt BF seem to work very well with the PST Mod.

I have a couple of guys using the Lunt 1200 with no issues.

[Ransu]

Thanks for info! I have to start think about purchacing Lunt BF1200