Help using a barlow with a DSLR

[AstroMum]

After seeing how tiny shots of Mars come out on my 80mm APO, I tried to use my 2x barlow to increase magnification. I popped the barlow into the focuser, then my Canon 1100D with 0.8 reducer attached.

I can't seem to focus the image at all, I just see a large blurry spot of brightness that doesn't change a great deal regardless how much I adjust the focuser.

The barlow (a 2" Revelation ED Astro) can be broken down into three sections - the lens cell, a metal tube and the part which the eyepiece is screwed into. I get the impression the lens cell can be used alone, but it doesn't attach to my DSLR/reducer.

I'm no doubt doing something obviously wrong here, but I'm far too new to this to have any idea what it is. Can anyone give me some pointers? Is the problem that I need an extension, or is the barlow itself too long?

[nmoushon]

I'm no tech wiz but my first inclination is to say that the spacing of your slr is off now because of the barlow adding so much mag. Not sure if thats actually whats wrong but just my guess.

[Merlin66]

OK

If you're using a barlow you should use a reducer - one increases the scale and the other reduces it.

Try with just the barlow in the focuser then add the camera body - see how you go.

[jgs001]

Gotta agree.. Just the barlow... it'll still be tiny though... you could try using the video mode of the 1100d... not sure if that uses a smaller area of the sensor.

[AstroMum]

Righto, will do some experimenting without the DSLR first, assuming we ever get some clear skies again.

I'm not too worried if it doesn't work, as you say John, it will still be tiny. Might make for some nice lunar close-ups though!

[Star Gazer]

Dont know if this helps but I had to use an extension tube with my Powermate and my Megrez 72

Also the sequence they connected is important to be able to get focus. The sequence is: Megrez + extension tube + Powermate + DSLR. I suspect you might have the same issue.