Filter between lens and film plane on Perkeo II

Discussion in 'Medium Format Cameras and Accessories' started by 36cm2, Jan 30, 2012.

  1. 36cm2

    36cm2 Member

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    I remember reading somewhere that one could install a filter (e.g., for additional contrast in black and white) inside a Perkeo II between the lens and the film plane. I can't find the post anymore. Has anyone done this or seen it done? I typically use a green-yellow filter with this camera and can't close the camera without removing the filter. I dislike all the putting-on, taking-off, particularly because I'd like to take it easy on the struts/lens assembly Just wondering if this alternative is feasible and whether it would degrade the image more than placing a filter on the lens. Thanks for any help you can provide.

    Leo
     
  2. jeff.blackwell

    jeff.blackwell Member

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    I don't know if this will help, but I have a Perkeo II, and by chance tried one of the three stepping rings from a Century Optics wide angle adapter on it. The stepping ring fit, and fits tightly enough against the lens for me to be able to close the camera without taking it off. Now I just use screw on filters (49mm) and while I'm careful to support the lens and struts, there is no real force placed on those parts of the camera. I just gently screw filters and/or the wide angle adapter onto the stepping ring. It works very well, and now I can get the equivalent of a 55mm lens when I use the WA adapter with little or no vignetting, depending on the aperature I use. Century Optics adapters are especially attractive, because they transmit light so well, there is essentially no loss of exposure. Most adapters, both tele and wide cost you a stop or two of light. If you measure the lens diameter, maybe you can find a stepping ring to fit, you'll be set. I'm at work, and don't have the camera with me, but I'll check when I get home. I believe its a 29 or 30.5mm diameter.
     
  3. 36cm2

    36cm2 Member

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    Jeff, sorry if I didn't understand well, but are you saying that with that stepping ring you can close the camera with the filter in place?
     
  4. jeff.blackwell

    jeff.blackwell Member

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    No the filter must be removed, but the stepping ring can remain attached, which makes it much quicker to screw the filter on when you open the camera.
     
  5. DWThomas

    DWThomas Subscriber

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    I have a Perkeo II, but I fear if I put a filter inside, I'd suddenly be needing/wanting to change the filter with ten shots left on the roll! The external and on and off bit can be a PITA though. At least push-ons are quick to attach and remove, except for what to do with them when they're not attached.
     
  6. 36cm2

    36cm2 Member

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    Thanks, Guys. Any ideas on whether doing this would degrade image? Does before or after the lens matter? I know i've heard of it being done in large format.
     
  7. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    Generally, it is better to have filters in front of the lens than behind the lens, and if behind the lens, better that they should be thin filters like Wratten gelatin filters, and that they be absolutely clean.

    That said, you could try taping a gelatin filter cut to size across the film gate, inside the rails. That method is particularly useful for infrared photography with an SLR, where you might want to use a very dark red filter, but you still need to be able to compose and focus. There's no reason you couldn't try the same approach with regular filters for B&W with any kind of rollfilm camera, as long as you can keep the filter clean and scratch free, and you don't have to change filters midroll. Why not give it a go?
     
  8. 36cm2

    36cm2 Member

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    I love this place.
     
  9. jeff.blackwell

    jeff.blackwell Member

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    36cm2 -
    I checked the stepping ring/ adapter lens setup, and what I have is this:

    1. A 30mm - 37mm step up ring attached to the Perkeo lens. It was one of three stepping rings that came with the WA adapter.

    2. A Century Optics 0.65 wide angle adapter, with 37mm rear threads. I mount this to the stepping ring on the Perkeo, back focus by a third ( i.e. my subject is at 30 ft., so I set the hyper focal scale on the lens' focus ring to 20 ft.), and If I'm shooting at f8 or smaller, I have a sharp image at the equivalent of 52mm focal length. Larger aperatures can make for interesting attempts at shallow DOF and selective focus, but since one is unable to view the image through the lens with the Perkeo, its at best an educated guessing game.

    3. A second 37mm - 49mm stepping ring, which I attach to the first stepping ring (which stays attached to the lens virtually all the time) when I want to use filters. I got a whole bunch of inexpensive used 49mm filters in lots of varieties.

    4. I also found a hard plastic lens hood with 37mm rear threads very cheaply, and I can attach that when necessary.

    I'll try to take some photos of the parts and camera, both separate and attached and post them tomorrow.
     
  10. jeff.blackwell

    jeff.blackwell Member

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    Last edited by a moderator: Jan 31, 2012
  11. jeff.blackwell

    jeff.blackwell Member

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    This is somewhat unrelated, but has anyone ever tried to use this larger version of the WA adapter on a Certo 6?

    http://www.bhphotovideo.com/c/produ...0HD_65CV_46_0HD_65CV_46_0_65x_Wide_Angle.html

    While I love the small size of the Perkeo, the speed of the film advance on the Certo makes it very attractive, and I have one that doesn't get enough use. I'm just so used to being able to have a second focal length with the Perkeo, I haven't explored this option yet. It might be my next project when I have some extra money.
     
  12. 36cm2

    36cm2 Member

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    Thanks Jeff. Based on your description it sounds like that working well for you, but it seems awfully complicated. I'll have to take a closer look at the whole setup.