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Astrogeordie

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Everything posted by Astrogeordie

  1. Those TOWA 114/1000mm instruments were once popular despite of their lower performance, compared to the "straight" 114/900mm Newtonian TOWA built as well. It was sold by companies like Bresser/BOB, Tasco ("13T"), Eschenbach and Revue which was the German equivalent of the "Prinz" brand of the Foto Quelle mail order company. They had a reflex finder that was in prinicple one of those dreadful 5x24 non-achromats, and as the tube you looked through using the finder was not parallel to the main scope, it was increadibly difficult to find anything. The corrector was in the draw tube, so the effective focal length changed when moving the focal plane. The same design was built as 76/600mm table top telescope (I have one in my collection) and as 152/1300mm instrument which was quite expensive and not very successful. The front plate, while looking like a corrector, was indeed an uncoated flat.
  2. Hi Mark and Telrad, thanks for your nice comments. It was my first trial on M1 yesterday with the RCT - until now my best shot was with a Celestron 9.25 from Kielder, but only 1/2 hour. So it is getting better already, but this object still needs photons. Also I am restricted to short exposure times as I work unguided. Here an autoguider should step in shortly.
  3. Hi Trevor, nice one ! NGC891 is a nice object where with growing depth of the data more and more background (=companion ?) galaxies become visible.
  4. Hiya, after my "pop-art" mishap (see http://stargazerslounge.com/imaging-deep-sky/164806-m33-pop-art-little-mishap.html ), now an M33 of two nights. Altogether 57 x 2 min, GSO 10" RCT with optimised baffle, modified EOS40D camera, EQ6 pro, no guiding. Stacked with DSS and contrasted using Canon Digital Professional. Yesterday in a cold, transparent and windy night, I got 35x 2min on the Crab nebula: I had to shut the obsy after that as it started to rain in strong winds while the sky was still mostly clear !
  5. Oops, what happened there. Are the blue lines indeed introduced by DSS ? Never had one of those. I just remember problems with wide angle exposures where one side of the image "ran away" as the stars formed trails, while the other side was okay ...
  6. Hi, thanks for your comments. Yes, the amount of detail is not bad for 54 minutes. However, it is a 250mm instrument - not to forget. @Ben - is it a 250/1200 ? Should be a nice powerful instrument then - I have a self made one of this size. However, for photography I would put a coma corrector onto your wishlist.
  7. Last Tuesday (2011 Nov 22) evening we had a clear spell. Hence I opened up my shed to point the 10" GSO-RC on the EQ6 pro towards M33. Later the Crab nebula was on the agenda but it clouded up after one hour. On the other EQ6, the OMC250 revealed on Jupiter that the seeing was atrocious. Apart from the two main cloud stripes, no detail emerged and I just used this occasion for a coarse optical alignment. Back to M33. Next day saw me reducing the data with DeepSkyStacker and Canon Digital Photo Professional. Hence I pointed DSS to the Biases, Darks, Flats and Lights and off it went. 27 x 2 minutes - I could not expect a deep image but howay as the Geordie says. When contrasting with the Canon software I got surprised: What has happened ? Was the self made stop at the secondary of the GSO still not large enough, so I got straylight intake ? Will I ever get proper flats ? Is my technique with the pillow case - multi layered over the front of the scope, held in place with elastic band and shone at with my white LED torch - inappropriate ? Looking at the flats .... one of them seemed a bit out but I was not sure. So let's try it and remove it from the stack. Going to DSS, I could not find the file name ! Actually there were no flats with the file names of last night, but flats were there ! Only ... ... I am a SAUSAGE ! The flats I chose were - in total error - of another night one month ago, taken with another camera through another telescope (200/1000mm Newtonian) ! After this "small correction" ... or a brighter version (depends on screen ...): I hope you like it a bit. My partner found the "colourful" version nicer - but this is rather down to an arty taste than astronomy I suppose.
  8. I required two finder shoes for Skywatcher type finderscopes. 365 Astronomy had two in stock, brand-new and only 5 quid each. Ordered using Google checkout - the shoes arrived after a few days. Smooth transaction and good value for money, they were the metal ones.
  9. I was there from Friday to Sunday but stayed over night at the observatory to assist with the public events. Weather-wise it was quite a washout, with Saturday night strong winds adding to the rain - at least on the hill where the observatory is located. However - it is like fishing - and it is always nice to see the "family" again. I agree I would not have chosen to be in a tent and the drainage at the site could be improved. As a survivor of Kielder 2004 I find the drainage on the top field has improved but it still could be better. However, wellington boots are important for any starcamp as washouts are quite frequent. Dalby was no better this year in this aspect - nobody can sort the weather out.
  10. The spike effect may be not as strong as anticipated as the scratches appear curved. So the direction of the diffraction changes along the scratch while the contribution in each direction is very small. The same as in a curved vane spider. By the way -- how has the picture been made ? If you use bright lights as a flash gun, even dust grains make hell of an appearance which is completely dramatising the effect they really have.
  11. Maybe it is just the coating. At first I would remove the mirror and soak it in luke warm water with some washing up liquid in it. Then, after rinsing, you may apply a bit of alcohol (Isopropylic alcohol or Methylated spirits) to remove the last residuals. Also distilled water can work here. Then look through the mirror at a diffuse light source. If you see the scratch, it went through the coating. It may have damaged the mirror but not necessarely did this. You may just use a fine line permanent black marker to blacken this scratch off against stray light, or you may go ahead to get the mirror recoated. Light loss wise the problem is negligible, but you may get some stray light. Hence the suggestion to blacken it out. I cannot really see a mouse scratching glass unless it had some sand on it that worked it's way in. However it is helpful to assure no animals get near optics.
  12. Leitz never really made large lenses apart from spotting scope ones. Unless this is an unusual one-off, the Leitz Wetzlar note maybe refers to the eyepiece end as I see a binoviewer there that may be a Leitz, als well as some eyepieces may. The telescope control system looks like a prototype or a home built one. Would be interesting to know about the previous owner and the history of this machine. I would love to refurbish it but - pickup only, so no way.
  13. A big thanks to everyone. I finally found a quote at Transglobal Express using a DHL service. Costs me £68.50 of which £20 are an insurance cover over £1000. I still suppose glass breakage is not covered, but at least loss. And "telescopes" are not menioned amongst "restricted items". Now I have to get the coffin to work to put more FRAGILE tape onto the box before seing poor Carl going. However, where he goes he will have it better as the guy is a Zeiss enthusiast and a proper mount is waiting for Carl.
  14. I assume you just get hold of one of the ribs and push it. Similar to the domes of our Physics department - works fine for small domes.
  15. I never understand why in such auctions there are eight bids already four days before the end ... what's the point in outbidding each other at such an early stage ?
  16. Hi Jarrod, I know exactly what you mean ... I had the bummers quite often on Ebay when there is an interesting old telescope (e.g. vintage Japanese) and the showstopper is "buyer collects". I had one situation where a 60mm refractor where packing is really no rocket science was collection only, I really wanted it but nobody bid for it. The vendor wrote in his description he wanted to scrap it if nobody bids ... not sure what fate the scope met. As a non-motorist a "buyer collects" is for me as much a bummer as for you the "UK only" is. Sadly, the silly regulations of some shipping companies as no cover for LOSS of items that contain glass mean that there will be more and more "collection only" or "UK buyer only". Years ago I advertised a mount on another forum. I got a PM of a guy in Italy who wanted to buy it. I sweated water and blood as I had lots of scam emails before ... and finally it came out the guy was a long established user in the forum and a nice guy indeed. So it makes sense to ship abroad. At least in this case I could find that the person in question had hundreds of postings of all sorts of astronomical discussions what proved he was genuine. But still I had to get used to send something abroad albeit I did it often to Germany before.
  17. The Yerkes Refractor is only an achromat, and the axial difference between red and blue is something like 19 mm when I remember correctly. Also the 1.25m Paris refractor was a lemon, partly due to the difficulty with the coelostates used as it is very difficult to make flat mirrors of 2m size in sufficient quality. A large Schiefspiegler should be a good one: - Apochromatic by definition - No central obscuration - Slow f-ratio, hence not many aberrations at the eyepiece end - Can be made larger than refractors at same cost and space envelope However it should have a tube well protected against currents coming from the observer. PS: The picture of the Paris exhibition refractor reminds me about CERN rather ...
  18. Hi Kharga, taking a luggage piece of 28 kg, the overweight charges easily cancel out any gain. Especially if you book a flight on a cheap airline where you get charged for everything else ... I got now Royal Snail (was at Post Office) - 130 quid including £1000 cover against loss (no breakage). At least there is a method but the price is shocking.
  19. Unfortunately I have no car ... and the guy sits in Bavaria, southern Germany. Thanks for the other links that I will try out tomorrow.
  20. Just checked Interlink Express. My parcel is too long, and items "made of or partly made of glass" are excluded from transport. Daft. When I look at their exclusion list I wonder what is left allowed to be sent ....
  21. Hi Mick, thanks for this. Usually I try to keep it UK only but this is a special case. It is a rare old German telescope and the buyer has a collection of this brand of telescopes. I just checked Royal Mail - 130 pounds insured to full value, but still unsure about the loss szenario. I think I will go to my post office tomorrow to learn more as at least then I would have my peace of mind. And the transport bill is shared between me and the buyer anyhow ...
  22. Hiya, I tried UPS (no way to get even a quote) and Parcelforce (nearly 100 quid and again the silly exclusion of fragile items even when being lost!). Royal Snail should be the worst way as they charge already astronomical amounts when sending anything to Germany heavier than 2kg.
  23. The problem is that Parcel2go offers different couriers, but has its own exclusion list albeit it claims it is the courier services that have those exclusions. Strangely when I look at DHL directly, telescopes are not excluded from liabilities. Just had a quick quote at FEDEX, they want nearly 100 quid for their "economy" rate. The problem is that business guys are getting much better rates ...
  24. Hi all, I just sold a valuable scope (about 1000 quid) to somebody in Germany. I tried to book a service at parcel2go but I found out telescopes are "restricted items". While I understand they are not liable for glass breakage, I was completely stunned to find out they do not take liability at all - so even if they lose the parcel, I get nothing back even when I forked out 47.50 for an insurance ! The "why" could not be answered by the guy of the service personnel I was chatting with. So do you know any company that can ship a 28kg parcel (120cm x 32cm x 42cm) to Germany and offers a fair insurance ?
  25. Hi Michael, the amount of mercury used is minimised by casting a parabolic resin shape at first. So the resin forms nearly the final shape and the mercury just covers it up to form the reflective surface. At least my colleague told me that - they used this method when he made his PhD, that was during the 1980s.
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