Cobbled together zoom eyepiece

[Dave Lloyd]

Having seen a S@N article on making an eyepiece from a 50mm camera lens I decided to try a zoom. I have an 18 to 70 kit lens from my Sony Alpha which is quite compact. I didn't want to wreck the lens so instead of bonding the holder tube to the lens front I used a 55mm skylight filter which you can pick up for a couple of pounds. This I epoxy bonded to an old Barlow flange. This assembly simply screws into the filter thread on the front of the lens. Haven't tried it at night yet but it's pin sharp on the local foliage. The only problem is that (on the ST102 at least) there isn't sufficient inward focus to allow use of the diagonal.

[Knighty2112]

Nice work Dave. Pity you can't get it to work in a diagonal. 

[Dave Lloyd]

Thanks knighty, it's a job for an observing chair (or a very good limbo dancer).

[Dave Lloyd]

On 17/09/2016 at 13:42, Knighty2112 said:

Nice work Dave. Pity you can't get it to work in a diagonal. 

Funnily enough it works perfectly with the crayford (sorry Olly) and 2" diagonal on the evo120. 

[Alien 13]

What a great idea I have always fancied a longer FL eyepiece with my scope, mmmm a 100 mm one would give me a magnification of X4.

Alan

[Dave Lloyd]

Great for star fields, although the S@N article I read had concerns about using too long a focal length. Think it was due to extended eye relief.