Which Scope To Use With Binoviewers And Az4 Mount?

[Chris]

Hi, I've been getting some good use out of an ST120 on an Ali AZ4 recently as it's really quick to setup and quite compact. The only thing is that I really like to use both eyes, and no matter what configuration I try, I can't get it to focus with my WO binoviewers.

This got me thinking: which specific scopes would work well with binoviewers, and at the same time sit nicely on an AZ4 ? (I have the ali legs on mine, but scope choice can be based on any type of legs as these are easily swapped out).

One more conditon is budget, I'm thinking hundreds not thousands.

Planets, Moon, Sun, and brighter DSO's are the usual targets.

Any thoughts on the above (other than my spelling and grammer ) ?

[Merlin]

We need a fairly long fucus 'scope for binoviewers. You wouldn't have a focusing problem with, say, a SKYWATCHER Mak/Cass.

I have a little SKYMAX 90. This is not an expensive 'scope and the optics are superb, giving excellent views of the Moon and planets with the WO binoviewer. 

[Merlin]

Just to add that the star diagonal that came with the SkYMAX 90 wasn't very good, so it didn't do justice to the fine optics. I replaced the supplied diagonal with a quality one. All of the SKYMAX range get good reviews for their optical performance.

Schmidt Cassegrain 'scopes are also good with binoviewers.

[tjr]

Going on Merlin's advise for long FL... An AZ4 with ali legs should cope with a Skymax 127. Steel legs will take a150 or even a C8 which can be picked up second hand for around £500. With longer FL or course comes higher mag which can be tricky with the AZ4, although with some practice tracking at around x200 is very possible.

[Fozzie]

That's interesting, I found that in my two fracs I couldn't reach focus with the supplied GPC on the WO BV's, even though every one I spoke with suspected no problems what so ever..

However  I have found that the nose piece from the standard 2x barlow, instead of the supplied GPC does allow me to find focus in both the frac's.. and at quite useable mags to with the 20mm EP's.

Maybe you could try this, other than that, 100mm of the tube should do it?!

Edit... Oh I believe various WO imaging frac's will also reach native focus, you know just to throw an triplet in there..

Ta

Fozzie

[Chris]

Thanks to everyone for your advice A small to medium Mak or SCT does seem to have the consensus. I'll do a bit of reading on the 4" and 5" Skywatcher Maks, plus possibly the C5 and C6 SCT's. 

The possible good news is that the above might now be a back up plan? Many thanks to Fozzie I have dismantled a cheap 2x Barlow and after screwing the nosepiece to the front of my binoviever, I think I can now reach focus!? I was focusing on the Moon through thick to moderate cloud but it definately looked promising, there was enough room to frame the Moon using a pair of 25mm Plossls.

I guess I'll know for sure once I've had the chance to look at the optical performance with clear skies. I might try and pick up a small Mak or SCT, so I can compare it to the ST120, then I'll just keep the one which performs the best with binos

Here's the setup avidly awaiting clear skies...... whilst also under low level attack!:  

[Fozzie]

Thanks to everyone for your advice A small to medium Mak or SCT does seem to have the consensus. I'll do a bit of reading on the 4" and 5" Skywatcher Maks, plus possibly the C5 and C6 SCT's. 

The possible good news is that the above might now be a back up plan? Many thanks to Fozzie I have dismantled a cheap 2x Barlow and after screwing the nosepiece to the front of my binoviever, I think I can now reach focus!? I was focusing on the Moon through thick to moderate cloud but it definately looked promising, there was enough room to frame the Moon using a pair of 25mm Plossls.

I guess I'll know for sure once I've had the chance to look at the optical performance with clear skies. I might try and pick up a small Mak or SCT, so I can compare it to the ST120, then I'll just keep the one which performs the best with binos

Here's the setup avidly awaiting clear skies...... whilst also under low level attack!:  

No problem Chris, I've no idea why the GPC doesn't work, at obviously that's the reason it's supplied (havn't tried them in the newt yet).. I've also no idea why the barlow nose piece does.. other than an assumption it pushes the focal point out far enough to work.  I might invest in the Baader 2.25x barlow as it looks (in the nice pictures at least) to have a better build although whether it will fit is another issue.. 

Low level attack.. veritable little army you have there, bless them!  Oli finds my Skytee fascinating especially the EP tray holder nut which he can spend hours just tightening and undoing, before he packs it away usually in the coal scoop.

good day to you..

Fozzie

[Fozzie]

using a pair of 25mm Plossls.

Hi Chris, how do you find the 25mm Plossls... any issue at the edges.. I ask due to (I think) they have a field stop of 21.5mm and the WO BV's have an aperture of 20mm, do you see any vignetting or the like?

Thanks

Fozzie