Ready Source of F3 Focal Reducers
Posted 08 May 2013 - 08:23 AM
Posted 08 May 2013 - 07:37 PM
Posted 08 May 2013 - 08:08 PM
Posted 08 May 2013 - 10:53 PM
The Meade 0.33X reducer is a 3-element reducer designed specifically to correct the coma and field curvature of the 'standard' SCT. It's a good deal at the $130-150 price often seen.
The Optec 0.33X reducer would seem to be expensive. For small-pixel cameras this might well be the better reducer. For analog video it will offer probably zero improvement over the Meade in terms of image quality, although the coatings might be better.
Posted 08 May 2013 - 11:22 PM
Posted 09 May 2013 - 12:36 AM
The other option is to stack a couple of reducers. The cheapest combination would probably be the Antares 2" .5x with a 1.25" .5x reducer ($110-120 for both reducers and the adapter). A useful adapter for this type of combination is ... http://agenaastro.co...l-t-thread.html
This 2" to 1.25" adapter has some beneficial features that make this stacked setup work. The 2" reducer threads onto the filter threads and the 1.25" reducer goes onto the video camera's 1.25" nose piece that is then clamped in the 1.25" compression ring. The adapter is long enough to get some reasonable reduction from the 2" reducer (most similar adapters aren't this long). If you want to get this combination down in the f3.5 range you'll also need to put a 1.25" extension tube on the front of the 1.25" reducer so you can move the reducer/camera back from the 2" reducer a bit. You could also adjust the spacing using T thread spacers but that would require an additional adapter to connect the camera.
Posted 09 May 2013 - 06:52 AM
Anyone know where to actually buy an f3 or F3.3 foal reducer? The only ones I see for sale are used and they go quick.
The options? Just keep looking. One will likely turn up. Quite a few folks who bought these in the small chip CCD days have moved up and will unload them. Want ad on Astromart might help.
Other than that? The choices are:
Live with an inexpensive .5x or pony up for the Optec or Uncle Rock's MFR-5...
Posted 09 May 2013 - 02:30 PM
Posted 09 May 2013 - 03:06 PM
You need the "Made in Japan" Meade 3.3. Evidently, there was a 'bad batch' of glass, so the newer ones are more of a 'pig in a poke' when it comes to quality. In other words, you can gaurantee a good one if it's "Made in Japan" or take a chance on the newer one.
Smiling Chicken Observatory
Posted 09 May 2013 - 10:14 PM
Posted 10 May 2013 - 12:26 AM
I am also very interested in f3.3 after realizing the good amount of difference between no FR and x0.5 FR with my Lodestar-C
Posted 10 May 2013 - 11:38 AM