2" Lunt solar wedge - objective types

[moriniboy]

A very simple question to set my mind at rest, can these be used with triplets  (120mm) and the Petzval type TeleVue's (101mm)?

Just a bit concerned about heat build up due to the number of elements involved.

I have used this with a 120mm ED doublet no problem.

[astrofox]

Petzval as I understand have an element at the rear. So that is a definate no no for a lunt wedge. I have heard of some triplets also suffering heat damage.

So to be safe I bought a doublet refractor to use with my lunt wedge. Didn't want to risk my expensive triplet.

[bob1957]

I only have experience with using my 2" Lunt wedge with a 102mm achromatic doublet and that works fine. Lunt does warn that the wedge must not be used with a refractor that has corrector lenses at the back. Would it be worth risking your expensive triplet for any perceived image improvement compared with your ED doublet.

[moriniboy]

Understand but I sold my 120mm doublet and bought a 120mm triplet lol

[bob1957]

As an update, strangely enough I've just finished reading an article in February's BAA Journal by Andy Devey about time-lapse techniques to observe the Sun. In the article Andy describes using his Takahashi TOA130 refractor with a Herschel wedge and two x2 Barlows in combination to obtain images. Now I believe the TAO130 is an air-spaced triplet (please correct me if I'm wrong). I don't know what wedge he is using but Andy says its safe up to 155mm aperture. His white light image in the article is amazing. Hopefully, moriniboy you'll get some other members of the forum posting who use triplets for Solar observing.

[Peter Drew]

I can't think why a triplet, particularly an airspaced one would be vulnerable as there is only ambient heat at this position, the no-no still applies to Petzval types. 

[moriniboy]

Thanks everyone, I have emailed Lunt for confirmation and will post their reply.

[russ.will]

I believe that cemented and oil spaced objectives can be an issue, but I've used my Lunt wedge in my 127mm Achro and 80mm triplet with zero issues.

I've also heard of people having issues reflective UV/IR rejection filters fitted on the wedge, melting front objectives, but not issues with plain old air spaced doublets and triplets.

Russell

[moriniboy]

Ian at Altair Astro confirmed ok to use it with the triplet.

Still no response from Lunt yet.....