New Toy

**Adam** · 02-22-2007, 05:06 PM

I never ever thought I'd find one of these, but I came accross one while casually browsing eBay.

This Pentax Monocular Converter turns any K-mount lens into a telescope, multiplying its effective focal length by a factor of 5. In other words, my 400-600mm mirror lens turns into a 2000-3000mm telescope! Plus, the view through the converter is much clearer than that through the eyepiece of a standard telescope

I guess it'll be fun to bring long on long trips

*dave kitson* · 02-22-2007, 05:47 PM

That looks fun.......

dave

roy · 02-22-2007, 06:15 PM

what's it like on the 500f4.5??

roy · 02-22-2007, 06:17 PM

oops, also, what's the diameter of the lens closet to your eye?
also, what's the effective magnification?

**Adam** · 02-22-2007, 06:23 PM

The diameter is roughly 1 cm, and the effective magnification is 5x, as I mentioned above. I haven't tried it with the 500mm because of the weight, but it's feairly easy to manage at 400mm with the mirror lens. Things get hard to locate at 600mm, but the picture remains clear. This adapter also works well with teleconverters

**roentarre** · 02-22-2007, 07:57 PM

This sounds like a clever device. I saw it in stan's website but I did not know you can still get it on ebay these days ...

Maybe hoping to see your photos from it?

slipchuck · 02-22-2007, 08:22 PM

would this converter with a big lens let enough light in to take photos, or is it just for your eyes only?

looks like a cool little thing to have

cheers

randy

**Adam** · 02-22-2007, 08:25 PM

I don't see how I could mount it on the camera, lol, but there's more than enough light for the eyes, even at 6000mm

knoxploration · 10-19-2009, 07:28 PM

I replied in another thread related to the Monocular Converter K, but figured since this is a fairly rare accessory that few members seem to have, it couldn't hurt to ask here too.

Could anybody with the Monocular Converter K confirm whether or not it will hold the aperture wide open on lenses without an aperture ring?

Also, if anybody has had a chance to try one of the third-party clones of the Monocular Converter K, do you have any comments on image quality / build quality / size and weight in contrast to the Pentax original, and whether or not they can hold the aperture open without modification?

Thanks to anybody who can offer assistance - I'm really quite interested in this gadget to accompany my camera and lenses when hiking etc., but don't want to spend a hundred bucks or so to find that it won't work with my gear, or the cheaper clones offer a better proposition.

*MGV* · 10-27-2009, 02:08 PM

you lucky guy, I guess I will have to step up my search for one.

Red · 10-27-2009, 02:30 PM

Gave up searching for a Pentax, I have often thought about getting a off brand. I'm the quality difference is huge.

General Brand | Pentax K-Mount Lens Monocular Converter | BT828

*wildlifephotog* · 10-27-2009, 02:45 PM

Here is an easy to build P&S mount. It attaches around the eyepiece to allow the P&S to do afocal shots through the unit.

knoxploration · 10-27-2009, 04:58 PM

Originally Posted by Red

Gave up searching for a Pentax, I have often thought about getting a off brand. I'm the quality difference is huge.

General Brand | Pentax K-Mount Lens Monocular Converter | BT828

If you get it, please do report back here. I can't find any forum members having stated they owned one, and I'm sure I'm not alone in wondering if the quality is decent.

Almost bought the Pentax one second-hand on B&H, but wanted to see photos first and somebody bought it right before they had the photos posted for me...

*tomwil* · 10-28-2009, 02:22 PM

Originally Posted by knoxploration

Could anybody with the Monocular Converter K confirm whether or not it will hold the aperture wide open on lenses without an aperture ring?

According to this PhotoNet thread:

Pentax made some neato items over the years, monocular k was one of them. Of Course its useless on current DA lenses as one really needs a aperture ring to shut down the telephoto lens to improve image quality. DA have no aperture rings so thats not an option.

Going by the statement, it appears it does leave the DA len's aperture wide-open, as the poster wanted a smaller aperture to improve the image quality (and I would guess a dimmer view).

knoxploration · 10-28-2009, 05:38 PM

Originally Posted by tomwil

According to this PhotoNet thread:

Going by the statement, it appears it does leave the DA len's aperture wide-open, as the poster wanted a smaller aperture to improve the image quality (and I would guess a dimmer view).

Interesting, thanks for the good info tomwil!