focul reducer?

[libraryman]

I want to image with my 350d DSLR and Vixen 102fl, it's f/9 900mm

what would be the prefered option on focul reducers to turn it into a good wide feild imaging scope and visual use as well?

Ray

[Jarvo]

Hello Ray - Consious no ones replied to your thread.

I've just bought a 0.6 x Focal reducer for my Makstuov Cassegrain 150mm telescope. The reducer is 1.25" and screws into the eyepiece or the camera adapter.

This is a cautionary tale as these pieces of kit can take a while to get the best out of them. Read up on the experiences of others on this forum - I took some photos with mine the other night and just got an image with severe vignetting. (Looked like I was staring down a tube) You need to experiment with distances between the reducer and the DSLR if you proceed.

Mine was inexpensive (£25) but the others that screww into the back of the scope can be £100 plus any extension tubes.

Cheers

Jarvo

[hemihaggis]

you would probably want to reduce your F to around 4 or 5

[ollypenrice]

you would probably want to reduce your F to around 4 or 5

...but I very much doubt that this would be possible. You need to find the right forum for this question. Have you tried for a Vixen forum somewhere? There are reducers optimized for different focal ratios. One place that might know is Telescope Service. You could try Orion Optics who have dealt with Vixen products for years.

Olly

[libraryman]

Thanks folks, yes i agree; i took the time to dig a little, Telvue sell one £225 or there abouts, even a good make like that could create issues if it's not spaced correctly.

However; it appears that Vixen made there own just for the 102 flourite, i'll put some feelers out for that.

Thanks again.

Ray

[libraryman]

Orion Optics, never thought about them, they're just up the road.

Cheers Olly

[ollypenrice]

That's good. Spacing is always critical with reducers but adapters are available from Telescope Service and Baader Planetarium amongst others. You can't guarantee all mixes of scope-reducer will work. Eg no one knows of a reducer that will work with our TEC, unfortunately!

Olly

[Macavity]

Yay! The focal reducer calculator is back:

Focal Reducer Calculator

This one actually give the unvignetted imaging circle diameter too.

Aside: Put in MAK numbers above: For a MAK150 (f=1800) with the (f=80 Atik) and chip distance of 40mm, you do (I sense in practice too!) get 0.5x reduction over unvignetted circle approx. 21mm. At 0.3x reduction, you're down to a circle of just 8mm. Could theoretically cover SMALL chips. Can be fun to experiment budget reducers... But "who knows" re. the image quality?

[obscura]

That's a useful calculator and already saved away for ref. when I take that step.

Many thanks

[HD-AP]

Hi

I use a celestron f 6.3 reducer on an f9 vixen atlux ,using a custom adapter ,but this was for slr film astrophotography not electronic imaging.

Their is now a 3.3 reducer availiable as well .

[Petervde]

Hi Olly,

You should take a look at the Astro-Physics 0,75 focal reducer for your TEC. I don't own a 140mm TEC, but I have read some positive comments about the TEC/AP-combination.

I own a 110mm f/6.5 TEC in a 'William Optics suit' and use the dedicated field flattener for that, but it's not a reducer.

Peter

[ollypenrice]

Hi Olly,

You should take a look at the Astro-Physics 0,75 focal reducer for your TEC. I don't own a 140mm TEC, but I have read some positive comments about the TEC/AP-combination.

I own a 110mm f/6.5 TEC in a 'William Optics suit' and use the dedicated field flattener for that, but it's not a reducer.

Peter

Thanks Peter, I'll look into that. I thought TS told me it was not entirely successful but I'll have a look.

Olly