PDA

View Full Version : Nikkor LF lenses - where to service?



Guy Tal
30-Dec-2003, 11:58
My Nikkor M 300/9 is exhibiting a strange light leak (a rectangular area in the center is overexposed). Any ideas what it might be and where I should send it for service? It was bought used.

Thanks,
Guy

David Karp
30-Dec-2003, 15:38
Guy,

Depends on where you are located. There may be a local repair shop that is familiar with large format lenses. You can always ship it to S.K. Grimes. A lot of people here in Los Angeles use Mel Pierce Camera. Calumet also has a service department in Chicago that services large format lenses. I would feel comfortable sending a lens to them. I found that many camera repair shops have no idea what you are talking about when you consult them regarding large format lenses and shutters. They would always say something like: "I have never done it, but I am sure that it is not that hard." This may be true, but I hate the idea of being their test case. If all else fails, I have never heard a bad word about the S.K. Grimes shop.

Guy Tal
30-Dec-2003, 15:46
Thanks Dave! I'm located in Utah but if I can't find anyone local, I will ship to SK Grimes. I'm assuming Nikon USA does not service LF lenses(?)

Guy

David Karp
30-Dec-2003, 15:49
Guy,

Perhaps your local Nikon authorized repair center can handle it, but I would make sure that they have some significant experience with large format lenses. For starters, I would give them a call with your problem, but would also check with S.K. Grimes via telephone before you decide where to send your lens.

QT Luong
30-Dec-2003, 18:40
Maybe I'm the only one criticizing the SK Grimes shop, but last month I sent a 110XL to be remounted on a new copal and I got a f-stop scale calibrated only to f45 with no sub-fstops markings (all my other lenses go to f64 with 1/2 or 1/3 stops markings) with a fairly loose lever, and no follow-up on my email complaint.

David G. Gagnon
30-Dec-2003, 19:30
Guy,

I'm thinking of a light leak around the lens. Have you checked your mounting of the lens on the board? A small void around the lens, such as an unused or not completely filled old screw hole or air hose hole can do weird things to what you'd expect to be a normal image, but it probably won't show up on the ground glass- just in the exposure. Also check that the mounting flange completely covers the hole, or if you're using a retaining ring on the back of the board, make sure that there is not a light leak at the spanner wrench slot(s).

DG

Kerry L. Thalmann
31-Dec-2003, 00:33
Guy,

Before you send it off for repair, check to make sure the little positioning set screw (locking pin) has been removed from the back of the shutter. If you've recently re-mounted this lens on a new board, this could be the source of your problem. This little screw is supposed to mate with a corresponding hole or indentation on the lensboard to prevent the lens from turning (commonly used on the old Graphic press cameras to secure the lens in the proper orientation when using a solenoid to trigger the shutter). Even though almost no one uses solenoids any more, most new lenses still come with this little screw installed. If this screw is left installed when mounting the lens on a board without a mating hole, it will cause the lens to sit slightly cock-eyed on the board. This can be enough to cause a light leak like you are seeing.

Kerry

Doug Dolde
31-Dec-2003, 11:26
A copy of the back of the warranty card from a Nikkor large format lens lists all the worldwide service centers.

It's here. (http://www.painted-with-light.com/nikonservice.jpg)

Michael S. Briggs
31-Dec-2003, 17:28
The lens alone may not be the cause of the problem. As others have suggested, I would look for a light leak. Perhaps between the lens and lensboard, as others have suggested, or perhaps between the lensboard and camera, or in the camera bellows. For example, the bellows is probably stretched differently with a 300 mm lens than with your other lenses, and perhaps this reveals a pinhole. The problem with some of the possibilities that I have listed is that they would probably cause an off-center area of overexposure. Can you tell us more about the symptoms? Is the over exposed area in focus? Exactly in the center of the film? Does it move if you use substantial rise?

Another possibility is that the shutter blades aren't fully closing, producing a pinhole at the exact center. You could hold the lens up to the light and check to see that the shutter blades are fully closed.

You could also check and see whether a film gets exposure even if you never trip the shutter -- remove the darkslide for awhile with the camera in sunlight and the shutter closed and then develop the film. Most of the possible causes would lead to exposure without tripping the shutter. One cause that would not is light from the lens reflecting off of something in the camera.

Presumedly your 300 mm Nikkor-M is in a Copal shutter. If the problem is with the shutter, than almost any camera repair person should be able to fix it. Since the lens was purchased used and is therefor probably out of warranty, there would be no particular reason to send the shutter to an official Nikon pair station.