I saw a beautiful image by one of our members who used a super fast Celestron RASA. This scope is so optically fast that he dispensed with guiding and dark frames because the exposures are so short. I thought, I have another telescope in mothballs, a vintage Takahashi Epsilon-130 f/3.3 hyperboloidal astrograph. That's just about as fast as the RASA (f/2.2!) and ZWO cameras have very little read-out noise and dark signal, so let's give the Takashi a try at the unguided, no dark frame approach. Well, the first problem that popped up is that the focus travel was designed for T-rings and DSLR film cameras. I couldn't get a digital camera to reach focus. A little grinding and machining on the eyepiece holder fixed that. After collimating the scope (no small feat for this kind of optics), I gave it a try using the Pleiades as the target. I took 146 images at 20 s each for a total integration time of 0.81 hr; I also took and averaged 30 flats.

Another problem popped up in post processing: the light cone is really steep at the focuser and a 1.25 inch nosepiece is not a wide open T-ring and DSLR camera aperture, so I got really bad vignetting. Aside from having to deal with that in post processing, the quality of the telescope was evident in the sharpness of the stars in the raw frames. The collimation was a bit off, but not terrible. I didn't get the color I wanted out of some of the surrounding stars, but the transparency was pretty bad that night. I hoping to give RGB a try if I can fit the filter wheel to the current focuser travel. Another error I made was that, yes, no guiding did not pose any issues because the Takahashi mount on which the scope sits is very good, especially for exposures that were only 20 s long. However, while the mount is good, it is not perfect and over the duration of the imaging session the target had slipped enough that stacking in DSS was a bit dicey because of large offsets. So now I am armed with more knowledge and will try imaging with this scope many more times I hope!