Dodging the clouds and showers, I managed to get out last night (Sunday) for 1st light with the Mewlon 180 and DMK 21AF04 combination. I rattled off a couple of AVI’s with the Televue x2.5 Powermate and then just for fun, plugged in the x5 Powermate.
The M180 is a 180mm F12 ‘scope, giving an effective focal length at F30 of 5400mm for the x2.5 Powermate and F60 with an efl of 10,800mm for the x5 Powermate.
Saturn was at an altitude of 45 degrees and the seeing was between 4 and 5 /10 with clouds and showers disturbing the session. I am very pleased with the quality of the images delivered by the M180 – a very impressive performer for such a relatively small ‘scope.
I used Telegizmo scope and tripod covers to protect the equipment during the showers and my observing hutch kept the rain off the rest of the equipment. Signs of a desperate man eh?
Thanks for the nice words guys – I was astonished at the results from the x5 shooting at F60!
What is also now obvious, is that my Televue x2.5 Powermate is, err….not a x2.5 Powermate. When compared to the x5 Powermate, the x2 Mitchell resize is smaller, so the distance of the DMK chip from the X2.5 Powermate appears to be making it perform at under x2.5, which ties in with the explanation on the TV website.
Cheers
Dennis
Last edited by Dennis; 05-03-2007 at 04:45 PM.
Reason: x60 changed to F60 - Focal Ratio of F60
The M180 has a cast "foot" or "block" on the mirror cell, around 6.5 inches long by 4 inches wide. There are x2 M5 drilled and tapped holes at 3 1/8 inch centres and a very nice Vixen style dovetail rail is fastened to this foot by x2 M5 socket head cap screws.
A Vixen style mounting puck came with the M180 and this bolts onto the EM200 head using the x2 M8 socket head cap screws. The M180 mounting puck has a single clamping screw, but I also have the next model up where the clamping screw is a (larger) clamping block a la Losmandy, albeit smaller.
Compared to the WO saddle and dovetail plate (Losmandy style) this M180 fitting initially felt a little light and flimsy but in reality, for a 6kg OTA, it is more than adequate. I guess to over-engineer this for the M180 would push up the costs, so Takahashi did what was necessary rather than implement the heavier Losmandy style rail. The M180 is a delightful grab-and-go ‘scope as it is so light, compact and easy to handle given the integrated finder bracket/handle.
However, it is inconvenient having to undo the x2 M8 screws and then fit the WO saddle if I want to fit the C9.25 with its CGE dovetail rail, so I'll look at modifying a WO dovetail plate to use the x2 M5 fixing holes in the M180.
I’ll take some photos in the day or two and post them to help decode the above description.
Great image Dennis Expecially the 2,5x by the good details. I think that using the 5x is difficult to have good signal and low noise because of the high gain used surely.
Anyway, it's a great result for the setup used. I think you have a very good contrast scope so you'll have great pics with good seeing
Nice images Dennis, great to see someone having a go at Saturn, difficult object. Liked the x 2 resampling image best and the image scale with your 5 x Powermate looks awesome so lets hope for better seeing.
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Expecially the 2,5x by the good details. I think that using the 5x is difficult to have good signal and low noise because of the high gain used surely.
