Some new white light gear

[bob1957]

Hi Michael,

Tracing the light path confirms that it comes to focus inside the solar wedge even with the focuser fully wound in. I've calculated that to bring the focus outside the wedge to a point similar to that along the scope's centreline without the wedge would require shortening the tube by 40mm. I'm not sure how the barlow would help in this instance, but at this point I'm open to any suggestions.

Many thanks, Bob

[michael.h.f.wilkinson]

Hi Michael,

Tracing the light path confirms that it comes to focus inside the solar wedge even with the focuser fully wound in. I've calculated that to bring the focus outside the wedge to a point similar to that along the scope's centreline without the wedge would require shortening the tube by 40mm. I'm not sure how the barlow would help in this instance, but at this point I'm open to any suggestions.

Many thanks, Bob

40mm sounds like a lot to cover with a Barlow. How long is EP holder of the wedge?

[wxsatuser]

Hi everybody,

I have a 2" Lunt solar wedge to use with my Celestron 102mm f5 wide view refractor. I was hoping to get some white light views of the Sun today and after setting up with a 25mm EP I found that I can't get focus. It would appear that there isn't sufficient inward travel to bring the image to focus. I'm going to sit down tonight and layout the ray path, but has anybody had similar problems? Ideally, I don't want to have to shorten the tube of the scope if there is an alternative.

Cheers, Bob

Yes!

Same here with a 102SLT and 2inch Lunt.

I ended up trying afocal with a Revelation projection EP, no other filters and my 600D.

By the time I got going Sunday afternoon I had patchy cloud and bad seeing.

This is the best I achieved, single shot, just testing, before I had to pack up.

[michael.h.f.wilkinson]

For a single shot that is pretty sharp. the centre seems to be very close to focus. The bottom not so much

[wxsatuser]

For a single shot that is pretty sharp. the centre seems to be very close to focus. The bottom not so much

Yes thats what I found, it was hard to get all focused.

It had to be right in the centre of the frame but in the time I had, I never really achieved it.

I an sure it could be bettered given some time to play.

Bit annoyed as the last two days here have been perfect but had to work.

[bob1957]

The EP holder of the wedge is 46mm deep, but I'm using a 1.25" EP so the adapter adds a further 23mm. The EP projects 25mm into the holder+adapter. The light cone from the wedge is 26mm short of the front lens of the EP. Possibly if I had a 2" EP then it might just come into focus as I wouldn't need the adapter but unfortunately I haven't. Looks like it's either buy new 2" EP's (expensive and probably costs more than the scope is worth), or shorten the scope tube.

Wxsatuser, clearly the EP projection method works as you've got a pretty good single shot, but I don't understand how as surely the EP projection is still short of the focal point from the wedge.

Cheers, Bob

[wxsatuser]

I had a 2inch to 1.25 adapter in the wedge and the EP in that with 600D t ring screwed directly on the EP.

A quick measure from the centre line of the scope tube to the EP lense is approx 147mm.

The EP was fully retracted into it's housing as well, leaving the EP lense just about as close as it can get to

the camera sensor.