LF Focal Plane Shutters

Discussion in 'Talk About Large Format Gear' started by Ian Grant, Jan 10, 2018.

  1. Ian Grant

    Ian Grant Active Member Registered User

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    I don't know who else uses LF cameras with focal plane shutters, I have a few including a 5x4 Kershaw Soho Reflex SLR which I need to service - this has surprising movements for an SLR.

    A downside of many longer LF lenses is any lenses in Copal//Compoud #3 sized shutters have restricted high shutter speeds 1/100 if a Compound or 1/125 with a Copal, quite challenging if you want to shoot moving objects. There's also the challenges of using barrel lenses.

    In the UK the only camera made/sold here that's reasonably versatile with Focal plane shutter is the MPP MicroPress, however they are over priced on the second hand market and a bit over-rated considering they are just Sppeed Graphics assembled in the UK with minimal UK parts.

    Graflex Speed Graphics can be bought very cheaply from the US, OK allow 33% for import duty, VAT and cost of collection of the taxes, but you can get a very practical camera with a Focal plane shutter with speeds to 1/100 at bargain prices. I use mine a pre-Anniversary and a Pacemaker with a military Dallmeyer 420mm f5.6 Telephoto, an 8" Petzval and various other lenses like TTH Cooke triplets, RRs etc.

    Ian
     
  2. Ian-Barber

    Ian-Barber Admin Staff Member Registered User

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  3. Ian Grant

    Ian Grant Active Member Registered User

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    Jim Galli is often using modified lenses, so he mentions 14" lens cells in a from a 16" lens barrel. One common way to get soft focus is change the spacing of the front and rear cells, another is to place one element the wrong way around..

    The TTH Cooke Series II triplet lenses were sold as standard lenses as well as soft focus. TTH used a ring and later a handle system to alter the cell spacing so you could adjust to become soft focus. The later Series 11b Portrellic lenses with the handle aptly nick-named the knuckle dusters fetch high prices when they appear for sale.

    Jim uses Packard shutters or a home made guillotine shutter, or even a hat. In this country you can find Thornton Pickard roller blind shutter, large front mounting ones are quite usefull speed range from 1/15 to 1/90 but high speed versions were made with a top speed of 1/1000. They also made Focal,plane shutters, I have a Half plate version but it's the high speed version and not very practical as the slit width is quite narrow, it would have been used for something specialist, scientific use or maybe something like horse racing. Half cocked in the focus position the focus screen is covered except for the narrow slit, I'll convert it to a regular FP shutter.

    The Focal plane shutters on Graflex cameras and the MicroPress consist of a long shutter curtain with a number of slits, one slightly wider than the format, used for focussing and T, then deceasing sized slits, the speed depends on the slit width used as well as the tension, a more modern SLR just adjusts the slit width.

    There are other shutter options with older lenses like the Luc and similar single speed leaf shutters that mount to the front of a lens, they come in various sizes late ones have flash sync, there's also Norka barn dor type shutters - it's possible to make your own.

    Ian
     
  4. Ian-Barber

    Ian-Barber Admin Staff Member Registered User

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    My 150mm lens has a Copal #0. How do you rate this type of shutter Ian
     
  5. Ian Grant

    Ian Grant Active Member Registered User

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    Copal shutters are excellent particularly thee #0 & #1 sizes, the issue with any large leaf shutter is the restricted top speed which in most cases isn't a problem until you want to stop or at least minimise movement with moving objects.

    With my 360mm f5.5 Tele-Xenar the Compound #3 shutter has a fastest speed of 1/100, the Copal #0 goes to 1/500 and the #1 to 1/400 so there's a significant difference. The Copal #3 goes to 1/125 but that's not much better than the Compounds 1/100, I have the same issue with my 240mm Nikon W (Copal #3)

    If you look at old photo's of press cameras at sporting events they used home made Big Bertha cameras, usually a long FL lens (not a telephoto) attached to an SLR body to use the faster shutter speeds to stop action.

    Ian
     

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