i was just wondering what would be the positive or negative effect of putting a barlow on a barlow
comments anyone?
barlow on barlow
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harlequin2902
- Posts: 744
- Joined: Tue Sep 30, 2003 11:04 am
- Location: Singapore, Sengkang
Visually, you may notice the image getting dimmer and suffer some loss of contrast.
Photographically (e.g moon, planets), the same dimming effect is very obvious and slower shutter speeds are required for you to capture a sufficiently exposed image. This can be an impossible task if you don't have a good tracking mount.
Still, we rarely have to do resort to this though. Because IMHO :
1) if you had the $ for a second 2x barlow to give you a total of 4x magnification with your other 2x barlow but at the cost of image quality, why not compromise and get a 3x barlow instead ?
2) for those who are still able to achieve focus through their scopes with a barlow inserted BEFORE the diagonal, your barlow in that position should give you an additional 50% magnification. i.e a 2x barlow inserted BEFORE the diagonal would effectively function as a 3x in that position.
Photographically (e.g moon, planets), the same dimming effect is very obvious and slower shutter speeds are required for you to capture a sufficiently exposed image. This can be an impossible task if you don't have a good tracking mount.
Still, we rarely have to do resort to this though. Because IMHO :
1) if you had the $ for a second 2x barlow to give you a total of 4x magnification with your other 2x barlow but at the cost of image quality, why not compromise and get a 3x barlow instead ?
2) for those who are still able to achieve focus through their scopes with a barlow inserted BEFORE the diagonal, your barlow in that position should give you an additional 50% magnification. i.e a 2x barlow inserted BEFORE the diagonal would effectively function as a 3x in that position.
Samuel Ng