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I bought a new toy to play with. It's a 135mm/f2.8 lens I found used at B&H Photo for $39. I cut a hole in the back lens cap, glued a t-thread spacer to it, and built a little piggy-back rig for it and my DSI. Its pretty heavy, so I was a little worried that my ETX wouldn't be able to handle it (I have a counterweight on the bottom-aft), but it did a pretty good job (my usual periodic jerkiness tracking problem notwithstanding). I get about 2 degrees of field of view, which is about perfect for most open clusters and larger galaxies/nebulae.
The piggyback rig isn't quite aligned with the telescope, so I don't think I actually got M-39 in the one pic, but it's a decent pic anyway: lots of stars in the area - so many, in fact, that I can't really identify the area on my planetarium program. Clouds were moving in so fast, I made no attempt to be sure I was on target after slewing away from M-13. From centering M-13, it looks like the piggyback rig is canted up about a degree, and I made some adjustments for next time.
The weather should be clearer in the next few days(and the moon will be moving out of the way), so I'll hopefully get some better pics. I'll set up in a better area, too - these pics were taken outside my apartment, with a big floodlight 20 feet away, pointed directly at the scope.
If I can get my tracking issues worked out and get some luck with long exposures, I may buy a DSI Pro. I'm a little disappointed that the DSI uses a grid of filters to get color, making the effective resolution about a quarter what the advertised resolution is. Otherwise, I may just go back to a webcam for planetary work.
The piggyback rig isn't quite aligned with the telescope, so I don't think I actually got M-39 in the one pic, but it's a decent pic anyway: lots of stars in the area - so many, in fact, that I can't really identify the area on my planetarium program. Clouds were moving in so fast, I made no attempt to be sure I was on target after slewing away from M-13. From centering M-13, it looks like the piggyback rig is canted up about a degree, and I made some adjustments for next time.
The weather should be clearer in the next few days(and the moon will be moving out of the way), so I'll hopefully get some better pics. I'll set up in a better area, too - these pics were taken outside my apartment, with a big floodlight 20 feet away, pointed directly at the scope.
If I can get my tracking issues worked out and get some luck with long exposures, I may buy a DSI Pro. I'm a little disappointed that the DSI uses a grid of filters to get color, making the effective resolution about a quarter what the advertised resolution is. Otherwise, I may just go back to a webcam for planetary work.
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