BV'er first light

I finally got the Denk II with all the bells and whistles and a pair of 24 pans. This past week I put them in my 20" F4.5 dob. The normal OCS in low power mode and 24 pans gave me about 140X. I did notice a bit of astigmatism on brighter stars and I could not get as tight a focus on brighter stars compared to cyclops mode. I first put them on M13 and the view was pretty spectacular however the view was not quite as sharp as in cyclops. I fiddled with focusing my individual eyes for quite a while and when I was sure I got it right the image was still slightly soft but breathtaking nonetheless. I just chalked up the softness to the light going through so much glass, OCS, prisms, 24 pans, thats a boat load of glass. Next I went over to M17, whoa! incredible with 2 eyes. Using 2 eyes really seemed to bring out the fine contrast, akin to the cyclops view with a UHC filter. I hit most of the showpieces, M51, 57, 92, 97, N4565, M20, on and on. Next I wanted to see how it would do on the dim stuff like Abell gx clusters. I went to the heart of Abell 2151 in Hercules and could pick out only 2 galaxies in the FOV. I then popped in a 16 Nagler in cyclops mode, 144X, and 5 more galaxies popped into view, but they were very faint and were fading in and out. So of course there is some light loss but not a whole heck of alot. I also went to the planetary N6781 in Aquila. In the Bv'er the nebulosity looked great but the dimmer stars in the disk were invisible, but as predicted came into view in cyclops mode. I did numerous comparisons on other relatively faint DSO's witht he same result. To make a rough guess about the light loss I would say that using the BV'er in the 20" is like having a 15 inch mirror for each eye but YMMV. However the views of the bright showpieces were spectacular. I am not going to sell my cyclops EP's because I enjoy hunting the real dim elusive stuff. For showpiece DSO's the BV'er is a wonderful thing. After the sun came up i broke out the 4" Tak and Coronado solarmax 60 and attached the BV'er with 24 pans. HOLY CRAP! The 2 eyed HA view of the full disk of the sun literally blew me away. The level of detail in dim proms, filaments, and sunspots was mind blowing. Once again superior contrast with 2 eyes. I switched to cyclops and all the detail was still there, but you really had to look for it. In the BV'er those details just jumped right out at me. So I will probably keep the BV'er despite the slightly soft and mildly astigmatic star images as I was blown away with the sun and showpiece DSO's. I highly recommend that everyone give it a try. I am ordering some Edmund RKE's in an attempt to get some glass out of the light path and maybe improve sharpness a bit. All in all a great experience. thanks for reading my ramblings.

That was a great first light report, Vincent! May I ask if your Denke comes with the Power Switch X? I wonder how well does it works (as well as a zoom eyepiece?)

I look forward to more of your observation with your 4-incher ;-).

Ron B[ee]

Vincent,

Cool 8) I would love to binoview with your scopes. 20" dob at night and an SM60 during the day. Very cool.

I agree with your observations, BTW. Lose some light and sharpness. Gain some other stuff that makes up for most of that. I also agree with JimR that if you are an Xobserver (you push the limits of aperture and sharpness) you should retain your cyclops viewing skills by using them. They will atrophy and have to be relearned if you don't keep up with them. I am a lost cause and cannot go back.

Please keep the reports coming. First impressions only come once.

Clear skies,

Tom