Stacking Barlows

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Tachyon
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Stacking Barlows

Post by Tachyon »

The thread in which this discussion was going on was locked.

Anyway, the story so far....

If I stack two 2x barlows, I get 4x - if after the diagonal, but more than that if before. Also the image may degrade.

Another question: so is it 2x2 or 2+2?

In other words, if I have a 5x Powermate, and I stack a 2.5 Powermate on top, do I get >= 7.5x or >= 12.5x?

This is not an academic question, I'm trying to figure out how to max out my 8" on Mars for my ToUCam.

Thanks!
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qu1xs1lv3r
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Post by qu1xs1lv3r »

isnt it 12.5x.. cz if u stick a 20mm(45x) into 2x barlow u get 90x.. so 5*2.5=12.5x?
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weixing
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Post by weixing »

Hi,
Another question: so is it 2x2 or 2+2?
Not quite sure, but base on my experience, I think it is mostly 2 x 2 = 4x.

Anyway, can try out on Mars Watch where I'll get my 4mm from Airconvent, then we can try whether 12.5mm + 3x barlow + 2x barlow around the same as 4mm + 2x barlow. :P

Have a nice day.
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Airconvent
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Post by Airconvent »

qu1xs1lv3r wrote:isnt it 12.5x.. cz if u stick a 20mm(45x) into 2x barlow u get 90x.. so 5*2.5=12.5x?
would be 45 x 12.5 , I reckon that would give x562 which is probably too high for Singapore without a tracking motor.
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weixing
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Post by weixing »

Hi,
would be 45 x 12.5 , I reckon that would give x562 which is probably too high for Singapore without a tracking motor.
Did he said he is going to use eyepiece projection?? He is using a ToUCam, so I think he is not using any eyepiece.

Have a nice day.
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acc
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Re: Stacking Barlows

Post by acc »

Tachyon wrote:The thread in which this discussion was going on was locked.
That thread was locked as its been hijacked by questions completely unrelated to the original topic... :evil: :evil: Create a new thread when you need to discuss a new topic, else we might as well go back to yahoo groups.
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