adjusting focus on a Kalloflex TLR

[craig_supplee]

Hi to all. I am new here at the photo.net forums. I have a Kalloflex Automat K2

that seems to be off in focus. I have read several posts here about using a

ground glass (which I don't have and don't know where to get) to adjust the

taking lens focus. How exactly would you do that. I thought these were fixed to

the lens plate. I do see on my viewing lens that there is a small screw that

would probably let me adjust this lens. When I focus on an object, the actual

distance is different than what is indicated on the focus dial. What is the

correct procedure to make this correct. Thanks.

 

Craig

[martin_dake]

I can't answer to specific details on your Kalloflex; however, I have done this for other cameras. I use a piece of Wax Paper taped over the film gate. Then with the back open you will be able to view the image on this Wax Paper. Focus the image on something a long lng way away (infinity), this will now be where you adjust the infinity stop on lens.

 

I am sure I have seen this technique on a few sites.

 

Here's one site that shows this being done on an Agfa.

 

http://www.rolandandcaroline.co.uk/focadj.html

 

Hope this helps.

 

best regards

[john_shriver]

Usually there is some way to adjust the focus on the viewing lens. Some setscrews you loosen, or something like that, and then you turn it to focus it to "match" the taking lens.

 

If the taking lens is properly collimated, and focuses at infinity when the focus dial is at infinity, you don't need a ground glass. Take a picture of something over 1/4 mile away with the camera focused at infinity, with the lens wide open. If it's in focus, the taking lens is properly collimated.

 

Then focus the viewing lens so that it is in focus on this same object when the knob is at infinity.

[richard_oleson]

There are two possible issues: first, whether the taking lens is off (ie, when it's fully back to the stop, does it focus at infinity) and second, whether the viewing lens and the taking lens agree. The latter is usually more important in practice, since you judge your focus in the viewfinder and generally not by reading the distance scale on the focus knob. The advice above may help you figure out how your taking lens is set.

 

Once you know that, there are 2 basic ways you can adjust the viewfinder. The easiest way is with shims: if the focusing screen needs to come lower, place them between the glass plate and the metal frame; if it needs to go higher, place them between the bottom of the focusing hood (between the screws on either side) and the camera body. The "right" way is by adjusting the upper lens. As John has mentioned, this is generally secured with a set screw, which may be accessible or it may be hidden behind the front fascia panel (I don't have a Kalloflex to check, sorry) - if the latter, the screws holding the fascia panel in place are hidden under the leather along side the lenses. After loosening the set screw, you turn the upper lens to adjust its focus and then retighten the screw to secure it.

 

I know this is sort of a brief, general treatment. If you'd like me to try to walk you through it as you go along, please drop me an email.

 

This page may give you a bit of an idea of what's involved with sticking a focusing glass into the film plane; it might just add to the confusion, sorry if it does: http://rick_oleson.tripod.com/index-123.html

[craig_supplee]

I tried a short test tonight. I set the focust to 3' which is all the way out on my camera. I then set the camera up so that the film plane was 3' from a wall with target tape on it. My viewing lens does have a set screw to loosen so you can turn it in or out. I adjusted this using a magnifier lens till it was as sharp as I could get it. I then tried focusing on different objects in my small shop and measured the distances. They were all off by various amounts. I guess I have to wait until I can get outside and do the infinity test using tape on the back of the film plane. By the way, the actual distances measured shorter than what the focus dial showed.

[richard_oleson]

It's really hard to get it accurate trying to measure and compare to the engraved distance setting... a very small error either in your measuring, or the engraving, can throw the whole thing off. If you can get it right at infinity, though, I think you'll find it's very close everywhere else.

[craig_supplee]

Richard, I will try setting it up using infinity this weekend. If I can't seem to get it, I will shoot you an email for help. Thanks to all for the help.

Craig

[daryl_jorud1]

Craig, just a point of information about the Kalloflex....it does not use a ground glass or fresnel type focusing screen as found on other twin lens reflex cameras. Instead, Kalloflex uses a heavy glass condensor lens for this function. Should you decide to remove it for any reason, be extremely careful not to accidentally damage. Kalloflex is a supremely robust, yet precision built camera that will serve you well for a lifetime if properly maintained. Unless you are absolutely certain that you can service it without fouling up the inner workings, it would be advisable to send your fine photographic instrument to a competent service person. Paul Ebel (Lens Services) in Menomonie, Wisconsin is such a person.

[richard_oleson]

Whoa! I've never handled a Kalloflex, I didn't know it had such a different type of finder. Without being able to see the camera, I'm not sure how useful my advice has been.

[gary_turner1]

I removed the condenser from a Kalloflex once and as I recall there were small brass washers on each of the mounting bolts / screws. I should think these are used to obtain a critical focus. Maybe your Kalloflex was previously tampered with while cleaning out the dust from under the condenser and on the mirror? Not sure just how much impact a missing washer or two would have on the focus accuracy but maybe it's significant.

[craig_supplee]

When I bought the camera the finder was off the body along w/ the front plates. There were 6 small brass washers in a plastic container along w/ the various screws. I know they came from the finder as there are depressions in the paint. These were located between the baffle and the finder retaining frame. I just don't know if these would have come from the factory, or if someone tried to adjust the focus using these. Not knowing how many washers went where, my thought was that I could put the finder screen back on w/o the washers, and adjust the viewing lens to compensate. Logic to me says this would be the correct way, but who knows.

[daryl_jorud1]

If you haven't already done so, insert the shim washers and compare the focus against not having the washers inserted. It seems unlikely that you would have received an extra set of shim washers with your camera, especially in the partially disassembled state you obtained it. More likely, they had been part of the original assembly, were of a specific thickness, making them critical to precise focus. Again, use care, as the condensor is easily chipped...

[craig_supplee]

Trouble is, there are 6 washers and only 4 screw locations. No way of knowing which locations get the extra washer. That's why I was hoping I could compensate the focus by adjusting the viewing lense to make up for the thickness (.005"?)of the washers.