Baader MkIV Zoom & Baader Barlow

[Outcast]

I've recently acquired a Baader MkIV Zoom EP & it's dedicated Barlow.

On reading the instructions, it advises attaching the zoom element to the 1.25" nosepiece which renders a 2.25x magnification.

The Barlow will physically attach to the EP without use of the 1.25" nosepiece but, I'm unable to find any info on what this does to the Barlow magnification factor.

Does anyone know or, can venture an educated theory on what the resultant magnification might be attaching it directly to the EP lens element?

Cheers

[Merlin66]

Carlton,
I have and use the Baader Hyperion x2.25 Barlow for Solar imaging.
Mounted with it's 1.25" nosepiece in the BF and a T thread adaptor for the camera body.
This seems to give around x2.2 magnification.


The manual doesn't mention anything about "direct" connect.
I'd try and see. Measure the FOV with and without....
https://www.baader-planetarium.com/en/downloads/dl/file/id/356/product/3117/description_and_recommended_accesso ries_for_the_hyperion_universal_zoo m_mark_iv.pdf

[Outcast]

Thanks Ken,

There is this bit in the manual but, I'm not sure if this would apply if connecting to the zoom without the 1.25" nosepiece:

'Attach the lens unit without the Barlow-adapter (A)
directly onto many 1¼" eyepieces, whenever they do
not already have an integrated barlow element. The
result is a 2x Barlow with very good optical properties'

[Don Pensack]

It's easy to find out the exact magnification of any barlow with any eyepiece:
--Time the passage of a star (any star anywhere in the sky) from edge to edge in the eyepiece. Insert Barlow and time the passage of the same star from edge to edge.
--the ratio of the first timing to the barlowed timing is the magnification factor of the Barlow.

Example: Timing 1 is 4 minutes and 12 seconds. Timing 2 is 2 minutes and 6 seconds. 252/126 = 2X

[Outcast]

Thanks Don,

That is a very handy bit of information to know!!

This is what I love about this place, you just know someone will have some great bit of info & is more than willing to share it round.

Thankyou Sir, I will get on to this as soon as I get a clear night...

Cheers

[DeWynter]

Carlton, there is another way to find barlow magnification right at home and without a star. Just with a ruler.

1. Place a ruler somewhere in a distance. Say 6 meters.
2. Use an eyepiece with a narrow FOV so you don't have vignetting with barlow.
3. Place a scope on a mount and make sure that you can see only a part of the ruler without a barlow. And it's in the center of the view like on attached photo.
4. Count millimeters you see (N1).
5. Put barlow.
6. Count millimeters you see again (N2).
7. Divide N1/N2 = magnification factor.

I've found it's much more convenient (and accurate) than using a star.

[Outcast]

Thanks Ilya,

Another great tip & doesn't rely on cloudless night which, are becoming few & far between at this time of the year in FNQ.

Cheers

[Merlin66]

Carlton,
You can do the same counting bricks in a distant wall.

[rrussell1962]

Great info and ideas from the posts here! Would an eyepiece with crosshairs work for making sure the ruler or bricks were in the centre of the FOV?

[Merlin66]

Russell,
The OP was trying to determine the Baader Barlow effect.
If you’re testing a barlow and eyepiece arrangement using a cross wire eyepiece isn’t necessary.....just count the visible bricks.