A TLR approach not discussed so far

[AgX]

... at least I do not remember.


In the late 70 at KMZ one

-) took off the prism of a 35mm SLR, but kept the groundglass and field-lens

-) as substitute a lens of 40° angular view, a additional mirror and an eyepiece were set on top.

The idea was to gain with a lens of long FL (300mm) a finder that yields an overview.
Something lacking at SLRs and often discussed in comparison with non-reflex cameras. Only here it is brought to an extreme.
Once an interesting detail was found and centered, the upper mirror was flipped to 45° and the groundglass image appeared to be focused on.

In the prototype taking-lens, overview-lens and body formed a unit:

It never made it into production.

 

[Dan Fromm]

Hmm. Target acquisition is always a problem with long lenses, especially with the first long lens one gets. I remember wondering how I could ever find the subject with my 200/4 Nikkor the first time I looked through it. And I remember wondering how I could ever find the subject with my 700/8 Questar the first time I looked through it. Practice solved the problems.

In other words, interesting device but very much a solution in search of a problem. Thanks for showing it to us.

 

[AgX]

Maybe that is why it never made it into production. But I know some produced photo stuff, where I wonder much more.

A cheap and simple alternative would be mounting a sportsfinder on the hot-shoe. There even was such accessory finder made, but I never came it across. But such sportsfinder as assistance would work best when the lens is mounted on a tripod.
This KMZ idea though would allow to keep the lens handheld as one keeps the eye at the finder, but just flips that mirror. It is not clear though how it is flipped. Ideal would be the first stage of a double-stage electrical release.

 

[Sirius Glass]

The best approach for a TLR is to use an SLR with a prism ==> Hasselblad, Rollei, Bronica, Mamiya, ...

 

[Theo Sulphate]

... And I remember wondering how I could ever find the subject with my 700/8 Questar the first time I looked through it. Practice solved the problems. ...

I'm not sure how they did it, but the 3-1/2" Questar had a clever system that didn't require a separate finder. There was just the eyepiece behind the main mirror and when you looked through it, you saw a wide field. Flipping a lever gave you the telescopic view.

 

[Dan Fromm]

Theo, the Q700 isn't a telescope. It is a mirror lens in T-mount to be used on 35 mm SLRs.

 

[Theo Sulphate]

Theo, the Q700 isn't a telescope. It is a mirror lens in T-mount to be used on 35 mm SLRs.

Oh - 700mm f/8 - wow.

 

[AgX]

The best approach for a TLR is to use an SLR with a prism ==> Hasselblad, Rollei, Bronica, Mamiya, ...

But thy would not yield any benefit for using long lenses.

 

[darkroommike]

The best approach for a TLR is to use an SLR with a prism ==> Hasselblad, Rollei, Bronica, Mamiya, ...

TLR's are much more quiet, mechanically much simpler, and with no mirror slapping up and cranking down you can see your subject at the moment of exposure. And mine will take a prism.

 

[AgX]

I'm not sure how they did it, but the 3-1/2" Questar had a clever system that didn't require a separate finder. There was just the eyepiece behind the main mirror and when you looked through it, you saw a wide field. Flipping a lever gave you the telescopic view.

I did not know that. Looked it up:

It employs the same basic prinziplev as the KMZ design:
Via a flippable mirror one can choose between looking through the main lens or through a finder with a path alongside, underneath the lens barrel. There are changable enlargements at the eypiece too.

 

[Sirius Glass]

The best approach for a TLR is to use an SLR with a prism ==> Hasselblad, Rollei, Bronica, Mamiya, ...

But thy would not yield any benefit for using long lenses.

Would you like to tell that to my 500mm Hasselblad lens? How about when I use that lens with a Hasselblad 2XE extender? I would bet that you cannot get a focal length like that with a TLR.

TLR's are much more quiet, mechanically much simpler, and with no mirror slapping up and cranking down you can see your subject at the moment of exposure. And mine will take a prism.

I have never had the dreaded pseudo mirror slap problem and I have been using slrs since 1960. The pseudo mirror slap problem only exists in the minds of the writers of Poplar Photography and Modern Photography, not in the real world.

 

[AgX]

I would bet that you cannot get a focal length like that with a TLR.

You might not have realized but the body intended for this KMZ design and used for the prototype was a plain SLR, a Zenit in this case.
Basically one could have used any long FL lens, even with extender.
In the prototype though taking lens and accessory lens are seemingly mechanically fixed to each other, but that need not neccessarily be so. Though it yields the most sturdiest result. Beside that KMZ favourized kit designs in general for fast tele-photography.

 

[Sirius Glass]

AgX, I was talking about TLRs in general. I am tired of hearing the same fanciful clap trap about the nonexistent mirror slap. The nonexistent mirror slap is a poor attempt to foist the idea that RF camera owners can overcome the RF camera failings [Lack of what you see is what you get in depth of field, the ability to conveniently use polarizing filters, limits in both wide angle and telephoto focal lengths] if they lie loud enough and long enough. TLRs have the advantage over SLRs by having twice the optics costs so that they [the TLRs] can introduce parallax problems. The KMZ is in its own world.

 

[darkroommike]

Would you like to tell that to my 500mm Hasselblad lens? How about when I use that lens with a Hasselblad 2XE extender? I would bet that you cannot get a focal length like that with a TLR.



I have never had the dreaded pseudo mirror slap problem and I have been using slrs since 1960. The pseudo mirror slap problem only exists in the minds of the writers of Poplar Photography and Modern Photography, not in the real world.

It'd still be louder, I know, I have both. And I can not get a 500mm or a 500mm + a 2x what's that? A 1000mm f/16? Yeah, don't know the last time I shot something like that but I could shoot a 250mm f/6.3 and crop it. That would let me acquire photos faster.

 

[Sirius Glass]

1000mm f/16 tripod mounted for nature photography with a quiet lens shutter, not a focal plane shutter. With the distances to the subject for those photographs sound is not a problem. In fact I have never had a shutter sound problem. There is nothing wrong with a good Hasselblad Ker-THUNK nor the Whirr-THWAK of a Graflex or Graphic focal plane shutter.

 

[Neal]

I have to say that I would find the device quite handy when shooting sports.

Neal Wydra

 

[Luckless]

I've used similar things for sighting tools, and I think they would be great if adapted to an SLR. I've done bird-in-flight shooting, both by sighting over the barrel and with a red-dot mounted to the camera's hot-shoe, and I can be very accurate with it, but that transition between looking over the camera and getting to the eye piece is still annoying.

I would love to have a unit I could swap out on the top of my camera, even those scary modern things I own, and hold down a thumb lever to get an adjustable TLR view. Take pressure off the lever and it switches back to the SLR path. Bonus points if I can switch between two powers on the TRL and keep reasonable framing reference for the taking lens, and shoot in mirror-lockup mode.

(Personally I enjoy quiet cameras so that I don't have to listen to them as much as I worry about who else or what else might be bothered by them. And I can hand hold my TLR at a slightly slower shutter speed than I can with my SLR bodies, which can make it a little more interesting at times.)

 

[AgX]

I just realized that a german gunsmith near Wetzlar and related to Leitz had around 1930 designed and built a gun-camera that emploid a Leica Ic with mirrorbox, and with mounted on that box a second mirrorbox with sight and eyepiece.
Thus basically the same as that KMZ design. The german one did not make it to the market either.