I finally got to do some imaging last night.
In early December, I picked up this lens at the local markets for $30. It is a 135mm, f3.5 Luminar, with a M42 screw thread mount. It took me another month to track down a reasonably priced M42 to EOS adapter, but eventually I sourced a cheap one, so all up it cost me about $50 to get it on the camera. It seems to behave fairly well, with a little red biased chromatic aberation. I found that I could deal with most of it through processing. This image of the LMC is 20x3min at ISO800, darks/flat/bias calibrated with ImagesPlus 2.75 automatic Image Set Processing. What A great tool this is!!
Other processing with Photoshop CS2. Canon 300D, 135mm Luminar lens, Baader UHC-S filter taped on the end!
Great image, was that wide open at F3.5, stars look pretty sharp to the corners. I note that the Henize 70 Nebula is visible towards upper right of image, about the 2 o clock position from Tarantula neb.
How do you focus with a lens like that, use the viewfinder on a bright star, or by taking a series of short test images till good focus is made?
Thanks.
Scott
Nice shot Tony. Love the way you've managed to bring out the colour of 2070 and not satutate the rest of the image. Any lens that performs like that for $50 all up is definately a good buy and value for money.
Yes it was at f3.5. I tested it on a tripod about three weeks ago but haven't had time or clear skies to try it up until last night. I'm pretty happy with the performance of the lens. This is a slight crop, but the edges aren't too bad. Some IP starsize reduction therapy didn't go astray either. Focusing is a little tricky. True focus is not at infinity and with the UHC-S filiter taped on the end, the view finder was pretty dark. I ended up using several test shots. This is what I do with my SN10 as well. An external monitor helps the process too. I can usually get focus in about 5 min. I've tried Paul Mayo's Sirius companion method, but I failed miserably.
Nice shot Tony, I too have bought a cheapy adapter for my Eos to try some shots with my old FD lenses. I only hope they turn out as well. It would be interesting to see that same shot with a 200mm lens.
Nice image. Shame you couldn't fit a little more in, with 35mm film the LMC just managed to squeeze in using my 135mm lens. I guess with the digital it's just a case of doing another series and stitching them together.
Howdy Tony.
Its a very worthwhile lens,
With my focussing I use a little magnifier that clips on to the viewfinder and magnifies about 3x. Its a canon accessory for my old T70 SLR. Sometimes Ive used the Heartman mask method too, its not bad either, but a pain in the bum putting on, then removing again with I have the dewshield on
Scott
Thank you all for your comments. Much appreciated.
Roger,
I guess my framing could have been a little better. I am yet to try a mosaic, but your suggestion is a good one. My camera is not modified.
Paul
Quote:
Love the way you've managed to bring out the colour of 2070 and not satutate the rest of the image
Thanks. The UHC-S filter made it possible and I have a couple of tricks up my sleeve.
Phil,
Funny you should mention the 200mm lens. I picked up a 85-210 Super Marexar zoom (M42 mount) at the same market for $20. I haven't tried it for astro yet, but I suspect that it won't be the same quality as the 135.
Hi Tony,
Nice sharp image, good focussing and exposure, colour of the background looks a bit green, maybe it is, or is this a processing artifact.
By the way I noted you obtained an EOS/42mm adaptor at a reasonable price, is there a source for these, or was it a one of, im after one.
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