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Towa

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About Towa

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    Star Forming
  1. Well an up-date on my f/1.4 lens, I just found that my lens contains a coating of the radioactive element Thorium on one of the lens elements, and as such I would not bother taking any chances no matter how cheap. So I'm going to stop using mine. It does also question the use of any camera lens as you might not know what your getting, so best to stay clear. I'm contacting a webpage of an astronomy society that have a drawing showing how to make an eyepiece from a lens, and see if they will remove it or at least add some wording.
  2. With my refractor I can go from 40x, all the way up to 400x with just one pair of Antares 20mm Plossl eyepieces. By using different combinations of where you put the Barlow lens and an extention tube you can have a huge range of magnification.
  3. I was able to try out quite a few 1.25" diagonals ranging from £40 to £170 on a three grand APO, and I could not see any difference in the eyepiece with my eyes. The expensive one had better build quality, but then again the one costing £65 was also nice.
  4. Yesterday there was a 600m volcanic ash cloud over large parts of the UK. I was at Sheffield Uni and all afternoon it was clearly visible. At sunset it appeared like sheet Noctilucent cloud over the Manchester area. Several people have now been reporting how bad the seeing was in their area last night. Speaking with an astronomer who was outside of the ash cloud area reported normal seeing.
  5. Yes, I'm very surprised as well. A f/15 scope with a Cheshire is so easy. The first time I did one, I took it really slow, so as not to mess it up, and that took all of 5 minutes.
  6. The good thing with a mirror is that you can take it out to wash and rinse. I would guess that things get a bit more complicated with a lens based optic, recently Takahashi in America issued guidelines about cleaning the lens on some of their scopes, as capillary action can draw excess cleaning fluid in between the lens elements. I know how some people get about cleaning pollen from their optics, they might need to go into a darkened room if they get volcanic dust stuck onto the residue from pollen. Its been interesting listening to the experts on the TV talking about the size of dust. The bulk of material stuff that fell over the weekend at my location is considerably larger than the tree pollen that's about. The largest pieces we have collected are 1mm in size. The picture below is a 0.8mm piece taken from the telescope lens. I'm a bit surprised how far these larger pieces have been carried. Nearly all the ash that fell yesterday was the size of tree pollen or smaller. People will have different risk opinions regarding their equipment, personally I'm keeping my ED scope inside until the wind changes. The lens is already in need of a good clean and I think I would be gutted if it ended up with a scratch or mark from a piece dust that stubbornly remained stuck to the residue already on there. my main concern is that the cleaning fluid, lens residue and abrasive ash will produce a wet & dry effect on the lens surface, so I'm not taken any chances, particulary after it marked a binocular objective that I left out in the fall-out and then cleaned. I already have a 4 inch lens with a mark on the lens after cleaning, while people tell me it won't affect the optical performance, it's darn annoying to know its there, and I feel that if I sell the scope I would have to do the honest thing and tell a potential buyer about it.
  7. Towa

    Ash

    Last night I fitted some optical glass over the front of my refactor, after one hour of observing I had volcanic dust on it with this real swine sitting there. While hardly any is visible on the car, it was still coming down here in North Notts during the evening. Slides done this morning are clear at the moment.
  8. Towa

    Ash

    This dust is extremely abrasive, I've been doing tests on an old binocular objective and it's leaving scratch marks in the glass surface.
  9. Towa

    Ash damage?

    A nice article appears here about Sheffield. I have the same dust on my car and Scopes. Iceland volcano: Found on the streets of Sheffield, the volcanic ash which is falling on Britain | Mail Online
  10. Been using my 120 year old John Browning microscope today to look at the dust layer on my observatory roof. There is what looks like volcanic ash in the mix and the edges do look sharpe, the thing is can this stuff damage my telescope gear?. I'm thinking about what will happen if I try to clean a lens. I took some hand-held pictures, not the best quality but they give you an idea. In the second picture there is an awful lot of yellow/green particles, I think this is pollen, can anyone confirm?. There is two pieces of what I think is ash, you can clearly see a pointed side on the larger piece. The third picture has a monster of a piece. The picture does not do it justice, there is a great amount of detail in it when viewed through the eyepiece.
  11. All lathe work at the moment and just for fun Astorix.
  12. The stuff is now settling, Met office monitoring stations across the country are reporting volcanic dust on the ground. Today the glass roof of my car was covered with a fine dust, local university have confirmed that this dust is from Iceland. This afternoon the entire eastern sky was a brownish colour.
  13. Excellent images. I was some 200 miles south of you and had a wonderful volcanic sunset.
  14. Excellent shot, looks like there is some volcanic activity in there as well.
  15. Wonderful job, with superb jointing. Great use of different woods, do you study the work of Mackintosh by any chance at Uni?
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