Need suggestions to "Magnify" image

[Mkillmer]

I've just built an LF camera out of bits and pieces:

The lens is an ancient 13 1/2" Cooke Aviar Anastigmat.
Unfortunately the bellows draw prevents me from doing "Head and Shoulders" portraits.
Is there an solution to modify the optical path with something like a close-up lens to allow name to use it up close?
The lens has a diameter of 10cm.

Mark

[vinny]

Yes, a close up filter or a shorter lens are your 2 options. An extension lensboard works on some cameras but doesn't look like it will work with yours.

[Mkillmer]

Any ideas on how to get a 10cm closeup lens? He rear lens is a few cm smaller, can I put the lens on that side?

[Francisco J. Fernández]

Hi, I sometimes use these accessories to increase the length of bellows (or reduce the focus distance, which is the same or almost the same).

But other times I used close up lenses, when I could not pay much. Or when you could not do anything with a bellows (zoom in on a Fuji 617, I do it with close up lenses).

I hope this is helpful.








http://www.ebay.es/itm/Focusing-Ring...27ee597&_uhb=1


http://www.ebay.es/itm/New-Extension...3fd3887&_uhb=1



http://www.ebay.es/itm/22mm-Extensio...d27df49&_uhb=1


http://www.ebay.es/itm/30-40-70mm-Ex...d723583&_uhb=1

[Regular Rod]

That box section behind the rear upright with the back on it needs to be deeper. Build a deeper box for the back. Like you have now but deeper. Make a mock-up out of card to determine the depth necessary.

RR

[Mkillmer]

That box section behind the rear upright with the back on it needs to be deeper. Build a deeper box for the back. Like you have now but deeper. Make a mock-up out of card to determine the depth necessary.

RR

Great suggestion - I think you are spot on. I set up an 8x10 with a 14" lens next to the Aviar, and discovered that I only need 3 cm extra to get "Heads and Shoulders".
I will build a 4 cm extension to the red box and should be set. That'll be next weekends project!

[ic-racer]

Close up lens just shorten your lens focal length. Why not just get a shorter focal length lens in a shutter. You will need a lot of bellows draw to focus that lens. For example a camera made out of an 8x10 enlarger, rather than what looks like the focus assembly for a medium format enlarger.

What is your film format size? How much bellows draw do you have now? You can figure out how strong of a diopter you need or how much more bellows draw you need with the thin lens equation

1/p + 1/q = 1/f

You can convert you 13" lens to diopters (338mm = 3 diopters, etc) so a 1+ diopter lens makes your existing lens into a 250mm lens etc.

[Mkillmer]

Thanks for the input ic-racer.
I'm trying to use up the bits and pieces that I have laying around (mainly this beast of a lens!).
I tried a small 49mm +1 closeup lens mounted in cardboard infront of the lens.
close focus went from 2.5m away from the subject to <1m away- that was too close.
would a larger size closeup lens make a difference?

[ic-racer]

Thanks for the input ic-racer.
I'm trying to use up the bits and pieces that I have laying around (mainly this beast of a lens!).
I tried a small 49mm +1 closeup lens mounted in cardboard infront of the lens.
close focus went from 2.5m away from the subject to <1m away- that was too close.
would a larger size closeup lens make a difference?

The "+1" lens was too close, even with the bellows collapsed all the way?

[ic-racer]

As a visual reference, here is an example of my 4x5 camera that can focus a 300mm lens for a close portrait.