Internal reflections TK45

[Adam Long]

I've been shooting LF for about two and a half years with a Linhof Technikardan, mostly landscapes.

Is it normal to get stripes of overexposure around the margins of the frame? Seems worse on wider lenses (65 & 90 SAs) but I get it to a lesser extent with the 150mm Symmar. I'm pretty sure it's due to light reflecting off the internal frame of the TK rear standard. Not on every frame, but some really suffer and I have to crop in 1/4" or more, which can unbalance the composition or remove important elements.

Do I need to just compose less tightly or has anyone managed to kill the reflections? I'm thinking to trying sticking some black velvet strips in or something... thanks.

[djdister]

Can you post some examples of the problem?

[Steve Goldstein]

I encountered a similar problem with my Shen-Hao 4x5 even though the internals are painted flat black. A bright light source just outside the image area would create glancing reflections visible at the image edge. I tracked down some super-black adhesive backed flocking material through the amateur telescope community and put strips of it around the frame. They do lift slightly over time and require occasional slight pressure to re-adhere them, but they eliminated the particular problem I was trying to fix.

Here's the stuff I used. A sheet of the stuff is good for a lot of cameras.

http://www.fpi-protostar.com/flock.htm

[Bob Salomon]

1: Is the camera a TK or a TK S?
2: Are you using a Linhof bellows?
3: Are you using a compendium?
4: How old is this camera?
5: New or used?

Have you tried using a strong flash light to shine on the back where you suspect the problem is? You would have to load 4 holders and expose one sheet at a time for each of the directions that you shine the light from. Best to do this in a dark room. Develop the film and see if there is fog from the light. If so, you have found where it is leaking. Do this with a closed lens so the only light that could fog the film comes from the flash light.

6: Are the frames for the bellows bent or warped?

This is a very uncommon (rare) problem on a Linhof so answering these questions will be a help. Also, where are you located?
We have Linhof service centers in NYC and outside Chicago.

[Adam Long]

Thanks for the advice chaps. I'll try to post some examples when I get home, a recent shot has prompted the post.

I'm in the UK. It's a TK, not TK s, bought second hand, no idea of age other than I guess it is 1980s. I'm using the bag bellows (as far as I know original, there is no logo on them). Not using a compendium but I do shade the lens for most shots where possible. I have noticed the bellows frames are ever so slightly warped, yes. I'll check how much and in which direction tonight. I'll try the light test and do some careful analysis of affected frames to try and pin down the problem more precisely, but it is worst vertically down the sides of horizontal-format shots - i.e. where the film is closest to the camera body.

It sounds like this problem is not something I just have to live with then, that's encouraging! I had been told it was just part of 4x5 and some cropping was normally required.

The flock paper solution sounds exactly what I was thinking, but it's good to know it might be eliminated with a properly serviced camera.

[Bob Salomon]

Thanks for the advice chaps. I'll try to post some examples when I get home, a recent shot has prompted the post.

I'm in the UK. It's a TK, not TK s, bought second hand, no idea of age other than I guess it is 1980s. I'm using the bag bellows (as far as I know original, there is no logo on them). Not using a compendium but I do shade the lens for most shots where possible. I have noticed the bellows frames are ever so slightly warped, yes. I'll check how much and in which direction tonight. I'll try the light test and do some careful analysis of affected frames to try and pin down the problem more precisely, but it is worst vertically down the sides of horizontal-format shots - i.e. where the film is closest to the camera body.

It sounds like this problem is not something I just have to live with then, that's encouraging! I had been told it was just part of 4x5 and some cropping was normally required.

The flock paper solution sounds exactly what I was thinking, but it's good to know it might be eliminated with a properly serviced camera.

If the bellows frames are warped then you need a new bellows.

On the first production run of the original TK some rubber spacers were accidentally left off the first shipment that we received from the factory. So, while this is unlikely, it is conceivable that some of those were also shipped to the UK.

Rather then wasting time here you should get in touch with Linhof in the UK and see if they can't help you directly.

This is not something that you "have to live with" with a Linhof, or any other 45 camera.

A proper compendium, like Linhof's, is capable of blocking all light that is not making the image from reaching the film plane that comes in through the lens. The TK compendium does this with the accessory cropping masks that fit to the front of the TK compendium. But this would not block stray light that is coming from elsewhere. So have Linhof Studio check your camera.

[Ari]

It sounds like this problem is not something I just have to live with then, that's encouraging! I had been told it was just part of 4x5 and some cropping was normally required.

Definitely not part of 4x5 shooting, and not part of shooting with a Linhof, either.
Get thee to a service centre, and the problem should become crystal clear.

[Adam Long]

Samples below. The problem doesn't affect most shots, these are the worst I've had.
65mm Super Angulon

90mm Super Angulon

150mm Apo-Symmar


All of these shots involve grad filters and fairly fast changing light. Is a compendium hood compatible with those? I do make a point of shading direct light from reaching the lens.

Currently playing around with the camera to try to identify which surfaces are the culprit. What effect would I be looking for from a warped bellows frame?

Serial on the hotshoe is 9831224. There are two circular sponge spacers in the groove in each standard where the bellows frame sits, diagonally opposite top-left and bottom right as you look at the inside. I would prefer to avoid a trip to the service centre, at least in the short term, as I don't have another 4x5 camera and we're having extremely good weather in the UK currently!

[Bob Salomon]

Samples below. The problem doesn't affect most shots, these are the worst I've had.
65mm Super Angulon

90mm Super Angulon

150mm Apo-Symmar


All of these shots involve grad filters and fairly fast changing light. Is a compendium hood compatible with those? I do make a point of shading direct light from reaching the lens.

Currently playing around with the camera to try to identify which surfaces are the culprit. What effect would I be looking for from a warped bellows frame?

Serial on the hotshoe is 9831224. There are two circular sponge spacers in the groove in each standard where the bellows frame sits, diagonally opposite top-left and bottom right as you look at the inside. I would prefer to avoid a trip to the service centre, at least in the short term, as I don't have another 4x5 camera and we're having extremely good weather in the UK currently!

1: It isn't as bad as I feared.
2: The flashlight test in a dark room with a closed shutter will show where it is coming from and how much there really is. That is difficult to tell on these shots.
3: A shade is not nearly as effective as a proper compendium properly adjusted. Especially since these can be from indirect, bounced light, as well as direct light.
4: The compendium will let you use sliding grads.
5: While a trip to service may be inconvenient losing an important image or images is evenly more so. And, how do we know that this can't get worse? Especially if warped frame on the bellows is the culprit. Thsis should not take the service center long to diagnose and come up with the solution.
6: Those first TK cameras were a long time ago and exactly what the problem was and what they sent service I have long forgotten. And our service center from back then is closed and liquidated as the owner died. But Linhof Studion should know if they had resceived cameras from that same production run.

[Adam Long]

Thanks Bob. No, it's not a huge problem but I made that middle 90mm shot last week and cropping that step in the headland out was definitely not my intention!

I've just been playing around with a flashlight and it's fairly clear that the main light stripe is reflecting off the inner surface of the bellows frame, with the second stripe right on the edge being formed by the rear standard itself. The slight warp of the frame isn't causing any light leaks I can detect.

I think I'll try sticking some flocking paper in as Steve suggested, and if that doesn't work it'll go in for service. I'll keep an eye out for a compendium too -though on the lower two shots above the brightest part of the sky is inside the frame anyway.

Do you know if the reflectivity of the bellows frame been reduced at all in newer models? The plastic on mine is fairly shiny.