New SW 200p Question

[Geoffteeth]

Quick question for you all, I got a new SW200p and due to other commitments and Rain!! Have only just recently got round to having a good look at it. Please take a look at the pics and tell me if its normal for the focusser base plate to be a different radius to the tube, Light does sneak in here. I just wanted to check whether this is normal? When I fitted a new focusser to my old scope I had to shim this area with black foam but to be honest I wouldn't have expected to have to do this with a new scope.

Cheers all

Geoff

[Black Knight]

I think that's normal from what I can remember from my 200P.

[Bizibilder]

The focusser is made with a base that will fit a range of tube sizes - all down to economics of manufacture. If you want to you could squash some foam into the gaps to reduce the amount of light getting through.

[Black Knight]

Just checked my Quattro and it's exactly the same.

[MBJ]

perfectly normal,my 200p is exactly the same.

[russ.will]

Mine was just like that and it's not an issue in terms of light leakage. If it where, then all of these multi thousand pound ultra-light truss tube Dobs wouldn't work, as they are virtually all gap and no telescope! That said they do use shrouds for best results, but that is to stop leaked/reflected light achieving a direct path to the field lens of the eyepiece in situations other than really dark sites.

To check where these areas are, take your eyepiece and adaptors out of the focuser and look down the draw tube - Move your eye to the extremes and note the maximum extent of what you can see. This, plus everything you can see reflected in the secondary mirror are the only areas from which extraneous incidental and reflected light can cause a loss of contrast. If you do this and make small marks with a pencil at these points, you'll also know where you need to flock your tube, black your mirror edges, mirror holders, shiny nuts/bolts/screws, etc for maximum performance.

At no point during this process will you have noticed the gab twixt focuser base and scope tube.

Russell

[Geoffteeth]

Thanks all, just wondered.

[WaveSoarer]

Just checked and my one looks exactly the same.

[brantuk]

I took the focuser base plate off my 300P and used it to make a felt gasket out of that black velour you can get from Wilkinsons. It's also useful for flocking the tube if you want a day of sticky contorsionism to kill all the stray light bounce and increase contrast

[Andrew INT]

I took the focuser base plate off my 300P and used it to make a felt gasket out of that black velour you can get from Wilkinsons. It's also useful for flocking the tube if you want a day of sticky contorsionism to kill all the stray light bounce and increase contrast

Oooh, I like the idea of using the felt for flocking the tube. Does it cope okay with dew and such? How long can it stay on before it needs changing?

Kind regards, Andrew

[brantuk]

If you stick the edges and joins with a spray glue it should last for a good long time - mines been on 6 mths and no probs yet.