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keppar
15-06-2009, 04:16 PM
HI All
Would there be any problems using a DSLR, barlow on a refractor (travel) for imaging. Is a powermate a better choice?
Graham
Geoff45
16-06-2009, 03:06 PM
The main problem would be the fact that you increase focal length by a factor of 2 (for a 2 x Barlow). This means 4 times the exposure is needed, (although you get a bigger object). Since most refractors are slow anyway (f7 +), you may have trouble with faint DSOs. However, for planets, sun and moon it should work fine.
Geoff