Cutting down a monorail.

bmac · Jan 29, 2004

I am about to take a hack saw to the rail on my 4x5. The only lens I have on it is a 135mm, and don't plan on getting anything longer than 210ish (ever). The rail just basically adds weight, and gets in the way. Now I am going through the process of trying to figure out how long I need it to be. 90% of my shots are shot close to infinity, or a little less. I'm thinking 10" will be plenty long enough, even if I decide to do something close up? am I correct? Can I swing 8"?

Brian

Donald Miller · Jan 29, 2004

Brian,

For a 210 mm that would be 8 1/4 inches at infinity. If you were to ever do any closer focusing then you will want some additional rail length.

I shoot a 450 on my 8X10 for close up work. That would be the equivalent of roughly 225 on a 4X5. I find myself fairly regularly having my bellows extension out to 26 inches when 18 inches is infinity for the lens.

So if I were you and think that by some small chance that I may want to do a close up shot of something at some future date then I would allow something on the order of 60% addtional rail length above the 8 1/4 inches that the 210 mm lens would take at infinity. That would be about 12 or 13 inches total rail length.

However it is your camera and you should do what you want.

bmac · Jan 29, 2004

OK, looks like 135 mm ends up as 5.31 inches. and 1:1 focusing would need twice the distance.. so 10.6 +/- So 11" or 12" should be plenty... right?

bmac · Jan 29, 2004

Wow we posted at the same time My gut is telling me 12" now

Alex Hawley · Jan 29, 2004

Brian, before you make the cut (which is not revesible) try this: Take a sharpie marker and mark the rail where the standards are after you focus. Do this for a while in as many situations of movement that you encounter. Then, if you are quite sure you will never need more extension, cut the rail so that all of your focusing situations are accomodated. Takes a while to collect the data, but it lessens the chance of going too short and coming up short on that once-in-a-lifetime shot.

David A. Goldfarb · Jan 29, 2004

12" will take care of a lot of situations with 4x5". Can you get another rail? It might be handy to have on hand so that you can use the maximum bellows extension for when you want to shoot macro with a 210mm.

bmac · Jan 29, 2004

My dad is a machinist, I just showed the original rail to him, he said it wouldn't be a problem fabricating another one if / when I want one, so I am resting alot easier. The reason I want a shorter one (it is 20" now) is I have never needed it, and I have poked myself in the chest, neck, nose, etc several times under the darkcloth. lol

Aggie · Jan 30, 2004

DrPhil · Jan 30, 2004

I have an 8x10 monorail that I've been lugging around. Currently I have two rail for it. A short rail that is about 14 or 15 inches and the full length rail that is 33 inches. The short rail works great with my 240mm lens; however, using longer lenses requires the longer rail.

Since your dad's a machinist, have you thought about making an extendable rail?

Nige · Jan 30, 2004

or making a short rail and keeping the current rail for when you need it, or if you sell the camera.

cjarvis · Jan 30, 2004

Nige read my mind.

bmac · Jan 30, 2004

Now where would the fun be in that??? Happy owner of a 12.5" monorail today! hehe

philldresser · Jan 31, 2004

Bmac

Is that 12.5 Male or Female inches?

Phill

Cutting down a monorail.

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