44 replies to this topic

[SeattleScott]

I’ve been using the Baader Mk. IV zoom for a few weeks now. Really enjoying it! It does get a little ‘thin’ on FOV when you hit 24mm focal length on it, but still having it at a 48 degree FOV is very good for a zoom at that focal length. Some hobbyists and YouTubers state it’s more 50 degrees than 48 degrees, but the jury is still out on that claim. Most are 38-40 degree FOV. Using a zoom EP that can go from a 48(50?) degree FOV at 24mm, to a 68 degree FOV at 8mm, I consider pretty exceptional in the world of zoom eyepieces.
On another note, I just received the Pentax XF 6.5mm - 19.5mm zoom in the post today. I wanted to compare views between the Baader Mk. IV and the Pentax XF zoom. The Pentax has the Lanthanum glass and the Baader has their ‘Phantom coatings’ for clarity, brightness and resolution. The Pentax is more of a planetary and lunar zoom as its highest magnification is 6.5mm, whereas the Baader Mk. IV is at 8mm. Looking forward to the next clear night to compare the views through both zooms and see how they stack up against one another for high power viewing.

The BHZ has been measured at 44 AFOV, and reportedly 22.5mm actual focal length at the 24mm setting. A 10 Ethos has the same TFOV, so the BHZ goes about as wide as a 20mm Plossl. Not really advisable to use as a low power finder eyepiece, unless you have a very short FL scope (or accurate GoTo).

Granted, it is still wider than the standard 40-60 zooms, which often aren’t actually 40-60. But in general it is only roughly 10% wider throughout the range, so mostly you are paying for superior correction and optical performance.

[LDW47]

And my WL scopes and Lunt Ha scope loves the 10-30 Svbony zoom, a lot, eh

[scotsman328i]

And my WL scopes and Lunt Ha scope loves the 10-30 Svbony zoom, a lot, eh

Yes, it seems as though zoom eyepieces marry up very well to solar scopes for viewing. 

[LDW47]

Yes, it seems as though zoom eyepieces marry up very well to solar scopes for viewing. 

I have used a zoom with them for a few years.

[LDW47]

Then I throw in a Morpheus, up to 10mm, for a change of pace.

[Polyphemos]

 

And shift the telescope slightly forward.. A bit nose heavy and a bit of friction to hold it can do the job.

…..

Shouldn’t be the other way around, with the balance a bit tail heavy? That way removal of the eyepiece will move the balance closer to the axis of rotation, not further, or am I missing something?

[SeattleScott]

Shouldn’t be the other way around, with the balance a bit tail heavy? That way removal of the eyepiece will move the balance closer to the axis of rotation, not further, or am I missing something?

The idea is to go for the middle. Let’s say your eyepieces weigh about one lb. So make it balanced where it is half a lb front heavy. That way, with no eyepiece in, it is only half a pound out of balance. And with an eyepiece in it is only half a pound tail heavy. So as you swap eyepieces, it is never more than half a lb out of balance. This minimizes the friction required to keep the scope from moving while swapping eyepieces.

I think what Jon and I are saying is balance it a little nose heavy before you add an eyepiece. I think you are saying balance it so it is a little tail heavy with eyepiece. So we are all saying the same thing.

Edited by SeattleScott, 15 March 2025 - 03:37 PM.

[Polyphemos]

The idea is to go for the middle. Let’s say your eyepieces weigh about one lb. So make it balanced where it is half a lb front heavy. That way, with no eyepiece in, it is only half a pound out of balance. And with an eyepiece in it is only half a pound tail heavy. So as you swap eyepieces, it is never more than half a lb out of balance. This minimizes the friction required to keep the scope from moving while swapping eyepieces.

I think what Jon and I are saying is balance it a little nose heavy before you add an eyepiece. I think you are saying balance it so it is a little tail heavy with eyepiece. So we are all saying the same thing.

We’re all saying the same thing in different ways, the difference being whether you balance the scope with the eyepiece installed or not. 

[Jon Isaacs]

I’ve been using the Baader Mk. IV zoom for a few weeks now. Really enjoying it! It does get a little ‘thin’ on FOV when you hit 24mm focal length on it, but still having it at a 48 degree FOV is very good for a zoom at that focal length. Some hobbyists and YouTubers state it’s more 50 degrees than 48 degrees, but the jury is still out on that claim.

 

 

Myself and others have measured the Baader Mk 4 zoom at around 44 degrees at 24mm.  I use the beam projection method... I don't think the jury is still out.. 

 

Jon

[Jon Isaacs]

We’re all saying the same thing in different ways, the difference being whether you balance the scope with the eyepiece installed or not. 

 

Or one can balance the scope with an eyepiece that weighs about 1/2 as much as your heaviest eyepiece. Then add friction to hold it with no eyepiece/your heaviest eyepiece.  

 

In reality, I pretty much know how to balance my scopes and how much friction to use so all my eyepieces are balanced.

 

Jon

[pregulla]

I think lower priced zooms (like Celestron 8-24 or Svbony 7-21 etc) give you mid-range performance for a very affordable price. If you are looking for a good enough performance I'd stop there. If you want good value for good performance, then AMP SZ is probably a good option.

[dmgriff]

Svbony 3mm-8mm Planetary zoom. I have one and it is a good performer. AFOV is 56 degrees. Then, if desired, a additional one with the largest afov in your focal lengths of choice in your desired price range.

Edited by dmgriff, 18 March 2025 - 11:27 AM.

[scotsman328i]

Myself and others have measured the Baader Mk 4 zoom at around 44 degrees at 24mm.  I use the beam projection method... I don't think the jury is still out.. 

 

Jon

I agree Jon, the Baader Mk4 does seem tighter than the advertised 48 degrees at 24mm. It’s saving grace is the field of view does get much better the more you zoom in. It’s a great zoom. It really keeps images sharp and resolved all the way to 8mm. 

Edited by scotsman328i, 17 March 2025 - 01:04 PM.

[PKDfan]

I agree Jon, the Baader Mk4 does seem tighter than the advertised 48 degrees at 24mm. It’s saving grace is the field of view does get much better the more you zoom in. It’s a great zoom. It really keeps images sharp and resolved all the way to 8mm.

FWIW Ernest has measured the Mark IV zooms focal lengths as 22.5mm-8.5mm.

Its field correction distortion changes to where its almost zero iirc ~21.5mm area then increasing as the field expands. I found when using a 5X PM that least distortion area has the best image quality and generally makes the zoom perform much better than its already good performance.


To possibly an effective 1.7mm eyepiece @68° AFOV and long eye relief. Magic.



CSS
Lance
Edit EFL to 1.7mm

Edited by PKDfan, 17 March 2025 - 02:35 PM.

[scotsman328i]

FWIW Ernest has measured the Mark IV zooms focal lengths as 22.5mm-8.5mm.

Its field correction distortion changes to where its almost zero iirc ~21.5mm area then increasing as the field expands. I found when using a 5X PM that least distortion area has the best image quality and generally makes the zoom perform much better than its already good performance.


To possibly an effective 1.75mm eyepiece @68° AFOV and long eye relief. Magic.



CSS
Lance

Haha Lance, that’s ok, I don’t feel cheated.
I still love the Baader Mk. IV Zoom and the sharpness, resolution and contrast it provides. 

[PKDfan]

Haha Lance, that’s ok, I don’t feel cheated.
I still love the Baader Mk. IV Zoom and the sharpness, resolution and contrast it provides.

Oh i didn't feel that you got cheated !
I don't.
I just listed them for pedantic types like me where i like calculating correct equations.

It was my first eyepiece purchased and the amount of love i give it is making the other children rather resentful.

I wish i had enough Evolux infocus to use my Barlow with it and do the boosting trick like i can in my 100ED.

I posted i'd risk life & limb for my two T2's:- i think i'll add my zoom to that short list scotsman328i.



CSS
Lance

[scotsman328i]

Oh i didn't feel that you got cheated !
I don't.
I just listed them for pedantic types like me where i like calculating correct equations.

It was my first eyepiece purchased and the amount of love i give it is making the other children rather resentful.

I wish i had enough Evolux infocus to use my Barlow with it and do the boosting trick like i can in my 100ED.

I posted i'd risk life & limb for my two T2's:- i think i'll add my zoom to that short list scotsman328i.



CSS
Lance

Haha I know what you meant! Was just having a little humor with you. T2s are legends. I’d give up a finger or two to keep my 26T5 and 20T5 if I had to decide between them. 

Edited by scotsman328i, 17 March 2025 - 03:44 PM.

[PKDfan]

Haha I know what you meant! Was just having a little humor with you. T2s are legends. I’d give up a finger or two to keep my 26T5 and 20T5 if I had to decide between them.

Hahaha cheeky bugger !

Yummy T5 20mm slimmed downed greatness & a 26T5 ! You've got some right real garbage there sir so tell you what, i'll help you out, take them off your hands and heck even give ya a couple of bucks for yer trouble.


Yes ?


CSS
Lance
P.s. no !?! Oh alright. Dang it.

[scotsman328i]

The Baader Mark IV I find perfect for public nights. It keeps my eyepieces safer in the case than out of the case all the time. It’s great for either introductory views for the public, or I’ll use it for solo or club only viewing to find objects, zoom power in on those objects until I find the perfect magnification that I want, then switch out for my premium glass to truly enjoy the view. It saves switching 3-4 eyepieces out incessantly to find that magnification I want by simply twisting the zoom and finding it. Zooms are great! They’re not a fixed focal length ocular and may never have the performance of one, but they are definitely a fantastic tool to save time with eyepieces and get where you want to be very efficiently. There are many brands of zooms, some high quality and some lower quality. As for budget minded folks, IMHO I wouldn’t worry much about which one you add to your ocular collection. It’s simply a tool to get you to the image magnification you want.

     I wouldn’t consider a zoom eyepiece a replacement for any fixed focal length oculars…I consider it a tool to compliment your fixed focal length oculars.  

[scotsman328i]

Hahaha cheeky bugger !

Yummy T5 20mm slimmed downed greatness & a 26T5 ! You've got some right real garbage there sir so tell you what, i'll help you out, take them off your hands and heck even give ya a couple of bucks for yer trouble.


Yes ?


CSS
Lance
P.s. no !?! Oh alright. Dang it.

Lance, I’ll send them right over to you. Hold your breath until they get there.