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Thread: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

  1. #1

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    Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    This is my first post here, though I've been reading for a long time.

    I received this lens in the mail today. I want to use it on my 2x3 Speed Graphic with a tube extension on the board. I actually already have one already put together, but the glass was in pretty bad shape, so I got this one when it came up on eBay.

    But when it arrived, I noticed a problem. The diaphragm wouldn't close down all the way to f/32, and when I opened it all the way, the indicator arrow read f/6.3. I removed the set screw from the aperture ring and removed the ring. I found that the set screw goes right into the diaphragm and functions as a peg to open and close the iris when the aperture ring is turned. I figured this was the way it would be. The probelm seems to be that the entire diaphrgm mechanism has some how turned with in the lens barrel, so that when the ring is turned in one direction, its motion is stopped on one end by the aperture opening all the way, and at the other end by the peg reaching the end of the slot along which it travels as the ring is turned.

    I went to check the photos in the ad for the lens, and one clearly shows that the indicator arrow is lined up with the setting for f/4.5. So somehow between when that photo was taken and when the lens arrived to me, the diaphragm moved. But now it won't move back. I tried inserting a tiny screwdriver into the hole the set screw is meant to be inserted into, and then at an angle pushed in the direction the diaphragm needed to go in order for it to be where it belonged. It doesn't want to budge. I don't want to risk breaking it, so stopped to get some help, which I hope someone here can give me.

    Another issue is that the front cell does not want to unscrew. If I could get it off, then I would just use the iris from my other lens (even though the paint is in better shape and the numbers are easier to read on the 'new' one). Both cells on the old lens unscrew easily. The new iris also has a fair amount of oil on it, which I would like to remove, but don't want to try with the glass still there.

    I didn't pay much for this lens (so little that it's not really worth the return shipping cost), so I'm willing to take risks with it. But the glass is quite nice, so I wouldn't want to wreck it either.

    I'd be grateful for any suggestions.

    (I tried uploading a photo of the lens by following the instructions on the guidelines page, but the little loading icon just kept spinning for more than a minute, so I gave up. The jpeg file was only 750 pixels on the long side, and less than 200 Kb. Is there something I should know?)

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  2. #2

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    Hmm... I guess they loaded anyway!

  3. #3

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    Hmm... I guess they loaded anyway!

  4. #4

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    It has been a while.... but try this. Open the diaphragm all the way (it says 6.3 when you do?) Remove the little screw, turn the ring to 4.5, reinsert the screw, wiggling a bit until you find the hole inside that it fits in. It might be better to not quite turn the diaphragm all the way open, and not turn the ring all the way open (say 2mm short of full in each case) so that you have a bit of wiggle room either way.

    Each diaphragm leaf has a slot at one end. There are as many slots as leaves. The little screw fits into any of the slots, but only one is the right one. It sounds like someone removed the screw, turned the ring, and inserted the screw back in the wrong place. You need to undo that, as I suggest in the above procedure.

    If I remember this wrong, someone will straighten me out! I hope.

  5. #5

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    I think I remember doing something similar myself a long time ago. But it won't work on this iris. One of the photos shows where I removed the aperture adjustment ring, and you can see the hole that the screw fits into. That's where the hole is when the iris is wide open, but that hole should be right above the arrow. I moved the iris with the screwdriver tip until it was at the other end of the slot, and no new holes appeared. I slid it a bit further, and then another hole showed, and I was able to get the iris to its smallest setting. But that hole in the photo was the hole the screw came out of, and the one meant to open and close the iris.

    I got the other diaphragm apart, and found that what I wrote above is right. I also looked for ways to get the front cell off, so that I could just use the other diaphragm. One thread here, where someone else had a stuck cell, and got lots of suggestions. The one that worked was to freeze the lens and then use a rubber band and a 'big wrench'. I tried that, and the cell wouldn't budge.

    I really think that, somehow, the iris moved within the lens barrel. I live in Wisconsin, and it was cold today. Could that have loosened the iris and allowed it to move? Maybe it rode in the un-pressurized hold of an airplane? I don't know. But it does not want to move back when I tried pushing with the screwdriver. I'm wondering it if would move if I held the barrel in a vise and tapped the end of the screwdriver lightly with a hammer.

    So Im still stuck with two options: move the iris back along its track to where it belongs, or get the front cell off the barrel.

  6. #6
    Randy's Avatar
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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    You said you can't remove the front lens cell, can you remove the rear? If so, manually open the iris with a small round tool, like a pencil eraser, just gently swirl it around applying slight pressure inside the iris opening until it is fully open, then put everything back together, lining up the f/4.5 with the arrow.
    I don't know if this will solve the problem, but it is my only suggestion at this point.

    I have this lens on my Graflex Series D 4X5 - a fine performer.
    https://dl.dropboxusercontent.com/u/52893762/bigger4b.jpg

  7. #7

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    Thanks, Randy. I just tried what you said, but unfortunately, though I was able to get the iris open that way, it would only do it if the outer ring -- with the misplaced holes -- moved right back to its stuck position. When I tried to hold the hole in the position it's supposed to be in when the iris is wide open, I was not able to then get the iris open with the gentle circular pressure.

    The store that sold me the lens has offered me a full refund while keeping the lens as well, so it's a freebie. That usually means something like go ahead and mess with it less carefully. But the glass on this lens is as pristine as any I've seen on a lens this old (I wonder if it was stored well on a Graflex somewhere). I'd really like to save it.

    I think I'm going to try gentle tapping against the stuck hole, to try to move the entire diaphragm back where it's supposed to be. I still don't get how it was able to move in the first place, just sitting in a well-padded box.

  8. #8

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    If tapping the diaphragm with a hammer doesn't work, I'll go to the hardware store to get a hose clamp. Someone suggested putting one on the lens, and then tapping against the bit that sticks out of it in order to loosen a stuck lens cell. I still have the other lens barrel with iris that I can use.

  9. #9

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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    Success!

    I was not able to get the diaphragm to budge. I'm really stumped as to how this could have happened. How could it have somehow moved on its own and then be so tight that it will not move back?

    However, I then bought a correct sized hose clamp*, tightened it down onto the front cell, squeezed it in my shop vise, and gave the screw housing on the clamp a few light taps with a hammer against a screwdriver. As soon as it let go at all, I was able to turn it off by hand. I've put the excellent glass on the working shutter/diaphragm, and put the now-great lens onto my homemade 'tophat' board.

    On my 2x3 Speed, I can focus from infinity down to about 20 inches. I've read that this lens can cover 5x7, though I don't know that for a fact. Still, Randy says he uses it on his 4x5 Graflex, so it's overkill on the 2x3. But I got the lens on a broken down Graflex myself, which was almost free, and now this new lens was actually free, so I'm happy with the price!

    *I'm pretty sure I have one somewhere in my workshop, but I knew it would be easier to find one at the hardware store than to find one in my very unorganized workshop.

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  10. #10
    Randy's Avatar
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    Re: Iris Problem in Kodak no. 33 Anastigmat 7.5-inch f/4.5 lens

    Paul, I doubt very seriously that it moved on it's own. Most likely, someone at the store you purchased it from forced it at some point - so it was probably defective before it was boxed up. What I would suggest, since you get to keep the lens, just shoot it wide open - or - do what I did with one of the lenses that I messed up the iris on - I asked someone who had the same lens to set theirs at f/8 and measure the iris diameter for me - I then set my lens iris (a Wollensak 15" tele) at the same size opening, then marked the lens-board as f/8, and I just always shoot that lens at f/8. If you decide to do that let me know and I can measure mine at what ever aperture you like and let you know the iris opening diameter. Mine is probably in the same cosmetic condition as yours - looks like it has hardly been used. it was on the camera when I got it - and the camera, made in the late 40's, is pristine.

    edit - I believe that lens, the 7.5", designed made for the 4X5 format. They do make shorter focal lengths of the lens for smaller formats.
    https://dl.dropboxusercontent.com/u/52893762/bigger4b.jpg

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