Leica ASPH vs 12.5mm BGO

[Stu]

This is far from a review of any kind, but a comparison based upon a few hours solar observing this afternoon.

The seeing was very variable, going from excellent to very average and back again within minutes. I gave myself a bit of a scare by observing with the Leica during a period of poorer seeing, then switching to the 12.5mm BGO by which time it was excellent. I thought the Leica was a duffer after all!! Had to wait for it to turn again before convincing myself. After some comparison between the two during the excellent seeing, I can say that I found the Leica to be at least as sharp as the BGO, with a little better transmission and I would say slightly clearer on the granulation.

The major benefit is of course being able to zoom to the optimum mag for the conditions, whilst knowing you are not compromising on image quality. I suspect the clearer granulation is a by product of this, as I find it quite sensitive to magnification.

I had no issues with sharpness over the field of view, I suspect my previous problems were Barlow related which I need to investigate further.

The most significant negative to the Leica are the reflections off the exit lens which are not an issue with the much smaller BGO. This problem was removed by putting my coat over my head!!

The other slight issue is one of balance on Giro style mounts. The Leica is quite long, and this makes balance difficult when looking higher up, above 50 or 60 degrees say. I have made myself a counter balance which hangs down below the scope, above the balance point and this pretty much removes the problem. The Leica is no different to any of the larger Ethos/Delos type eyepieces in this respect though.

Still waiting a first light with it in the Vixen.....

Stu

[Pig]

Great report Stu  

Its good to know the Leica competes at a high level. I always think it is best to use some sort of cover to block the sun, did you user the cover with the BGO also ?

I look forward to reading more about it.