Need Experienced Help Finding Old Brass Lens(es) for LF & ULF Wet Plate Work

[polaroid_memories]

Hi all

I'm having a multi format wet plate camera built over the next few months, with a maximum plate size of 11x14, and am looking for some assistance on what lens(es) would best suite my needs and how I can find a lens to suit my various plate sizes...

I have been shooting 4x5 collodion plates for years, but with more modern lenses with shutters and aperture controls. But since I am going even bigger and deeper into this medium, I feel I need the proper and fitting glass to complement the elegant process.

So its fair to say I am fairly new to brass barrel lenses and could do with a bump to help set me on my way into finding the right lenses for this venture of ULF plates...

- So my lens needs coverage upto 11x14 and down too 6x6 for making plates from square 6x6 upto 11x14 including 7x7, 8x10 and a couple other obscure plate sizes as well.

- The lens will be used mostly for up close portraiture, from very tight full facial images to head and shoulder with some torso.

- I don’t want a petzval lens with its circular effect, but ideally I’m looking for a nice sharp and fast lens with some bokeh effect characteristics. No soft focus...

- What are the calculations or details I have to look out for to discern what coverage the lens will cover? Is it to do with the lens diameter, length, width, focal length etc…? What is the best way of understanding what a lens can do in terms of the parameters of its minimum and maximum coverage?

Thank you all for your kind and useful answers in advance

Nathan

 

[jimjm]

Nathan - I don't have enough experience with this subject to make any suggestions, but you may want to try contacting APUG member jimgalli , as he seems to have a fair bit of knowledge about older lenses for LF.
I suppose you could PM him here thru APUG, and he has a web site at http://tonopahpictures.0catch.com/ .

Good Luck!

 

[removed account4]

hi nathan

in addition to jim's site .. go to the largeformatphotography.info site
there are lens threads that show work done by specific lenses
there is a prices of soft focus lens thread that has live ebay auctions or just ended ones
so you can compare what you see with what they sell for on eBay...
go to flickr too and once you have a handful of styles/makers/&c of lenses
and type them in the search bar and you might also find some images with those lenses tagged.

john

 

[Dan Fromm]

- What are the calculations or details I have to look out for to discern what coverage the lens will cover? Is it to do with the lens diameter, length, width, focal length etc…? What is the best way of understanding what a lens can do in terms of the parameters of its minimum and maximum coverage?

Only one thing in your list of possible determinants of coverage has any effect on coverage. Focal length. Double focal length, nearly double coverage. Nearly because aberrations scale with focal length so for a given prescription far off-axis image quality gets worse as focal length is increased.

Coverage at infinity is determined by the lens' design, its focal length, the aperture used (stopping down tames off-axis aberrations, expands the circle of good definition), and the user's need for image quality. The worse image quality a user can tolerate off-axis, the larger the lens' image circle will be, other things equal.

Coverage at near distances can be calculated from coverage at infinity, whatever that means. Emmanuel Bigler gives the formula in post #3 of this discussion: http://www.largeformatphotography.info/forum/showthread.php?67361-Calculating-lens-coverage

A lens that covers a format (has image circle >= the format's diagonal) will cover all smaller formats.

Finally, this link https://onedrive.live.com/redir?resid=8D71BC33C77D1008!1005&authkey=!ACp3Kf30SHN3MwY&ithint=file%2cdocx will take you to a list of links to information on lenses ancient and relatively modern. Happy reading!