Atik filter wheels

[Rocketron]

Can anyone tell me the difference between the old style Atik EFW filter wheel and the latest EFW2.

I have got the chance of a nice used EFW, just not sure how good they are compared to a new and mega expensive EFW2.

Cheers

Ron

[steppenwolf]

Chalk and cheese! The original ATIK filter wheel worked OK but the engineering was nowhere near as good as the EFW2. I have both and they are very different from one another - the EFW(1) relies on the tolerance of the centre hub and a spring to keep the carousel parallel to the image sensor whereas the EFW2 has a finely machined hub backed up by two radial needle bearings and a wave spring. Orthogonality of the carousel is vital to avoid strange halos around stars using some filters.

That said, some EFW(1) filter wheels were better than others - I have a really good one that I'm hanging onto as it is lighter and more compact than the EFW2. The EFW(1) holds 5 x 1.25" filter against 9 x 1.25" filters for the EFW2, which explains the size difference.

[Rocketron]

Thanks Steve,

That helps to explain why the EFW 2 is such a costly piece of kit.

I think I am going to wait a while until I can fund a new EFW2, I've got a few bits and pieces of astro gear not being used so looks like a good excuse for a clear out.

By the way, my mother bought me 'Making every photon count' for last Christmas, she was ever so pleased to receive a letter addressed in person to her with the book.

Excellent book Steve, I would highly recommended it to anyone with an interest in astro-photography.

All the Best

Ron

[Gina]

Absolutely - brilliant book I too received a personal letter from Steve which was very nice and quite unexpected - I was very impressed

[ollypenrice]

WIsh I hadn't read this thread, since I have the humble EFW1! What makes it worse is that Steve knows what he's talking about!!

Sulking...

Olly

[steppenwolf]

Awww shucks, folks! I'm pleased you like the book and the personal letter - I wouldn't do it any other way.

The EFW2 is quite expensive but you have to see the quality of the engineering and then it all makes sense!

For anyone interested, I have reviewed it in some detail here and the inner workings are displayed for all to see.

Olly, I still have my EFW1 and in fairness my one works quite well but it don't think it was ATIK's finest hour, especially when you look inside whereas the EFW2 just oozes craftsmanship.