[MikePerham]

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I've been out shooting in Boston center and not seen ONE Pentaxian in over 3 years. Went on Scott Kelby's photo walk a few weeks ago and saw about 75 photographers congregate...Not one Pentaxian amongst them (apart from me). In fact, except for me and my buddy (shooting Olympus), everybody had a Canon or Nikon.

Well, the plebeian masses can shoot their Nikon and Cannon brands. Those of us who know and understand that there are alternatives and appreciate some of the finer points of the craft, can shoot Pentax.

[jslifoaw]

I've been out shooting in Boston center and not seen ONE Pentaxian in over 3 years. Went on Scott Kelby's photo walk a few weeks ago and saw about 75 photographers congregate...Not one Pentaxian amongst them (apart from me). In fact, except for me and my buddy (shooting Olympus), everybody had a Canon or Nikon.

I spent the entire summer (May-Aug) in Boston last year and, likewise, saw no Pentaxes.

[Miserere]

I spent the entire summer (May-Aug) in Boston last year and, likewise, saw no Pentaxes.

You should've let me know, I could have pretended to just be passing in front of your camera at some point and you would have had proof that Pentaxians do exist in Boston

[Blue]

They list a M42 version also
General Brand | M42/Universal Screwmount Lens to | BT831 | B&H

Neither are stock items, but if you want to wait a week or two. . .

They say that the m42 version isn't good for terrestrial viewing because it doesn't have an erecting prism like the k version has. However, the m42 adapter could be used with the k version on the 500mm f4.5 tak and allow the option to use it on the A 400mm as well.

M42:

Not ideal for terrestrial viewing, since no erecting prism is included in this design.

k-mount:

• Converts any K-mount lens to a monocular with erect image viewing (lenses mount just as they would upon a camera)
• Effectively acts as a 5x teleconverter
• Recommended for prime lenses 50mm and longer
• Simple fold-down rubber eyecup

[knoxploration]

B&H sells a generic version for $39
General Brand | Pentax K-Mount Lens Monocular Converter | BT828

I'm curious - has anybody tried the generic version? I'd love to know what the build quality is, whether it seems reasonably durable, and what the image quality is like (obviously that also depends on the attached lens, but I'd imagine the optics of the converter and especially the erecting prism would be the limiting factor.

Better still, if anybody knows how the generic version compares with the Pentax K-mount original for quality, size / weight and versatility, I'd love to know. Seems like for K-mount, short of making something myself (which I'm not up to), I only have three choices - find the Pentax original second-hand, get this clone, or I've found one other company offering a clone of their own which may well just be this same one rebadged.

Am I correct in thinking that when attached, the lens aperture is just held wide open and I then focus (and if appropriate, zoom) the attached lens to get a reasonably sharp view at 5x the lens focal length? Or do these rely on having a lens with aperture ring?

[MattGunn]

When attaced to the lens the aperture should be wide open and you only have to focus (and possibly zoom) to get a sharp picture. I have not tried a commercial one but I made a T mount one for use on my mirror lens; see here - https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/71775-mirror-lens-club-11.html
As has been stated earlier, with a monocular adapter and your eye you see a much better image than the cameras CCD usually does - you eye is much more adaptable and forgiving than an electronic sensor.

[knoxploration]

When attaced to the lens the aperture should be wide open and you only have to focus (and possibly zoom) to get a sharp picture.

Cool, so it should work how I was expecting... My one concern that I couldn't find answered anywhere was whether either the Pentax or third-party versions relied on having an aperture ring to manually set the aperture wide open.

[MikePerham]

Went on Scott Kelby's photo walk a few weeks ago and saw about 75 photographers congregate...Not one Pentaxian amongst them (apart from me). In fact, except for me and my buddy (shooting Olympus), everybody had a Canon or Nikon.

Isn't that sad! All those poor uninformed fools; heard mentality. Arn't you glad you are an individual?

[MattGunn]

Cool, so it should work how I was expecting... My one concern that I couldn't find answered anywhere was whether either the Pentax or third-party versions relied on having an aperture ring to manually set the aperture wide open.

Sorry I may have misread your question before. The aperture will need to be wide open otherwise the image will be very dark. With modern digital lenses with no aperture ring it is not so easy to force the aperture to stay open. However it is quite possible that the monocular will have a built in lever that opens the aperture when you mount it on the lens as a camera body does. If not then it should be possible to hold the aperture lever in the open position with bluetack or similar. Either way it should be possible to make it work.

[knoxploration]

Ah right, thanks for the clarification Matt. Back to my original question then. Anybody tried the Pentax or third-party variants, can you confirm whether they automatically open the aperture or require a lens with adapter ring set wide open? And if you've tried both types, how do the size / quality / durability compare?

[Pentaxians]

Did a search and found it, quite an old thread but would like to ask if there's anyone using this "Pentax Monocular Converter K" for bird shooting? Intend to pair it with my DAL 55-300mm, any comments? There's a guy selling for $180 in my area, worth it with the price?

[monochrome]

There isn't a ready market for those - they're rare as hen's teeth. The right price is whatever you are willing to pay, but at one time I would have paid that.

Bear in mind you'll probably need a tripod mount to use it effectively.

[pacerr]

Perhaps you misunderstand the function of the "monocular converter"?

It makes a telescope out of a lens. It would make approximately a 30X spotting scope of the DA*300. You don't use it as a lens on a camera body to "shoot" with.

[kh1234567890]

A useful toy. Mine sits on a cheap old zoom. ISTR that I paid about £5 for it. This one looks different - make sure that it has an inverting prism in it

They turn up on eBay all the time.