Baader Q-Turret 2.25x Barlow

[John]

The skies are no good for DSO's tonight but I've been trying out the Baader Q-Turret barlow with various ortho eyepieces on binary stars and on Jupiter before the latter sank behind our house. The scope used here was my Vixen ED102SS F/6.5 refractor.

The results are quite interesting. With the 18mm BCO, the barlow used in conventional mode creates an effective 8mm eyepiece but you need to find around 10mm of inwards focuser travel to bring it to focus. With the 10mm BCO you get a 4.4mm eyepiece and need around 8mm of inward travel and with the 6mm BCO you end up with 2.7mm (!) eyepiece that needs racking in around 6mm to reach focus.

When used with the 18mm and 6mm BGO's, which already need around 10mm more inwards focuser travel than their BCO counterparts, the additional inward travel that the 2.25x barlow introduces is really minimal - just 2mm with the 18mm and virtually no movement at all with the 6mm BGO (I don't have a 9mm BGO to compare with the 10mm BCO but you can get the gist of what the result would be !).

In terms of image quality the results of the above combinations were pretty impressive - little or no sign that a barlow was in use to be honest. The optics in this barlow seem to be top notch.

I then tried using just the optical element of the barlow in the shorter focal length orthos, the two 6mm 's and the 5mm BGO. As I've mentioned before, I find fitting and removing the barlow optical element rather daunting in the dark as there is very little containing the optical elements and it would be easy to drop them or get dirt on them. Once in the eyepiece barrels though the 1.3x amplification that they produce works rather well. I found I had excellent quality 4.6mm and 3.8mm eyepieces that produced almost textbook airy disks with the 102mm F/6.5 refractor when used on binaries such as Castor, Eta Orionis, Rigel and Gamma Leonis and very satisfying splits and star colour contrast where applicable.

This latter method of using the Q-Turret barlow does depend on there not being any lower lens set in the barrel of the host eyepiece though. The optical lens of the barlow requires 13mm clearance up inside the eyepiece barrel to be fitted.

If you have suitable eyepieces and are reasonably dexterous though, the Baader Q-Turret 2.25x Barlow is versatile and of high optical quality

[The Flinty Fox]

Thanks for that John. This barlow is on my shopping list along with some kind of motor drive for my eq mount. The slow mo controls are good but they can end up in difficult locations and even lose then all together. Just one thing, when you talk of inward travel do you mean the extra travel created by the barlow from pre barlow (eyepiece in and focused) to post barlow (need to re-focus)? Hope that makes sense.

Cheers

Paul

[John]

....Just one thing, when you talk of inward travel do you mean the extra travel created by the barlow from pre barlow (eyepiece in and focused) to post barlow (need to re-focus)? Hope that makes sense.....

What I was referring to was, from the point where the eyepiece on it's own was at focus, how much travel (inwards in this case) is needed to get the eyepiece to focus again when it is used in the barlow lens. Hope that makes sense.

What I forgot to mention is, when the lens of the barlow is used on it's own (as described in my 5th paragraph) screwed into the eyepiece barrel, the focus point moves outwards by a few mm.

[E621Keith]

Thanks for the review John. For the price, it sounds like it will be a good alternative to the TAL barlow.

I wonder if the Q barlow shares the same optics as the Hyperion zoom barlow.

[nightfisher]

A point to bring up with this barlow,in John`s full BCO review i commented that i had trouble using just the barlow element, I have had a bit of a play and it seems some of my ep barrels vary at the filter thread, maybe this is down to paint thickness, this element screws into some nicely, and some are tight

[Moonshane]

nice review mate. I wonder if one of these http://www.365astronomy.com/cmount-adapter-with-125-nosepiece-30mm-long-p-3289.html?zenid=527c2e1c854bcff28e81f5c9d52bc753 might allow users of eyepieces which it will not fit naturally to do so? might affect the magnification ratio a little but probably not much?

[John]

nice review mate. I wonder if one of these http://www.365astron...e81f5c9d52bc753 might allow users of eyepieces which it will not fit naturally to do so? might affect the magnification ratio a little but probably not much?

It would be fun to try. As you move the barlow element away from the eyepiece the amplification will rise (I think it works that way). With a full length extension like that you may well get similar results to using the barlow in the conventional way. You could in theory use a variable extension and have a variable multiplier effect. I've often wondered if the Nagler zoom uses this principle.

[Spec-Chum]

I thought all zooms used that principle to be honest

[John]

I thought all zooms used that principle to be honest

Quite possibly. And the Hyperion fine tuning rings work on this principle of course.

[Damo636]

From what I have read elseware, every 10mm of extension=0.1mm increase in magnification.

[Damo636]

I've worded my last post incorrectly, doh!

Every 10mm of extension results in the barlow amplification factor increasing by 0.1mm.

[Apollo Paul]

I just purchased one of these barlows. I wanted it for the 1.3x part. It doesnt work on my eyepieces.

I was never warned about this when buying over the phone.

I am quite annoyed they never mentioned this to me. Anyone thinking of buying one of these things

needs to check that the 1.3x part is compatible with their eyepieces before buying.

Paul.

[John]

I just purchased one of these barlows. I wanted it for the 1.3x part. It doesnt work on my eyepieces.

I was never warned about this when buying over the phone.

I am quite annoyed they never mentioned this to me. Anyone thinking of buying one of these things

needs to check that the 1.3x part is compatible with their eyepieces before buying.

Paul.

What eyepieces were you going to use it with ?

I did mention that it could only be inserted in certain eyepieces when I did the original report:

http://stargazerslou...e-story-so-far/

If the dealer is any good I'm sure you will get a refund.

[Apollo Paul]

I have only been a member since feb 3rd. I did use the search function but never came across that post.

I also emailed an astronamy shop, but they never replied to my question.

I then phoned two other places, both of which said the barlow would be fine.

The two eyepieces that i have are the meade 5000 UWA 8.8mm and baader hyperion 17mm.

The tuning rings for the hyperion i avoided because i dont fancy exposing the middle of the

eyepiece, nor fiddling around in the dark with them. Wish i had read your write up before i bought the barlow.

Paul

[John]

If you told the retailer that you wanted to use the Baader barlow element with those eyepieces they should have advised you that it was not possible, assuming that they know a bit about the products they are selling. In that case I would have thought that you should get a refund.

[Apollo Paul]

Yep. I let them know i had the meade, i also bought the baader at the same time as the barlow.

Also let them know i was more interested in the 1.3x than the 2.25x. He obviously was not aware

of the products compatability with certain eyepieces.

Sorry to sound so melodramatic over this. I am just frustrated. It arrived yesterday. If it were not for your review

i would not of found out until the next clear night sky. Cloud as usual here.

Thanks for your review anyway. At least people now know the 1.3x part will not work with some eyepieces.

Paul

[John]

No need to be down about it Paul - just contact the retailer and ask for a refund on the barlow

Not being aware of the characteristics of a product is no excuse for the dealer I feel.