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cyrus
1-Oct-2011, 10:31
My 11x14 has a 21" bellows draw. What would be a good lens for a 11x14 head & shoulders in-studio portraits?
I'm using it for wet plate photography so no shutter is fine.

Thanks all :)

Paul Fitzgerald
1-Oct-2011, 13:27
Your bellows draw limits you to 16" (400mm) or shorter.
Wet plate limits you to large portrait lenses and NO top-hat lens board, too heavy.

16"f/4 petzval, f/4.5 tessar, 420/5.5 Dogmar just squeaks in, 18"f/4 Verito.

I did test this a few weeks ago, relisted below:

Camera = Ansco 5A double extension studio 8x10
target = 60" from lens board
bellow draw = lens board to GG

lenses =
B&L 11x14 tessar 400/4.5 = 20"
Heliar
14"/4.5 = 17.5"
420/4.5 = 23"
480/4.5 = 26.5"
Dogmar
420/5.5 = 20.5"
480/5.5 = 26"
500/4.5 = 29" (mounts mid-barrel)
Extra Rapid Lynkeioskop 19"/6 = 26.5"
Verito 18"/4 = 21"
Vitax 16"/3.8 = 23.25" (rear cell well behind flange)
Varium 19"/4 = 26"
Voigtlander Petzval 20"/5 = 24"

B&L Aero-Tessar 610/6 = 41"

cyrus
1-Oct-2011, 14:35
Thanks paul but how do you figure that my bellows draw limits me to 16"? Just interested in the math.

johnielvis
1-Oct-2011, 15:08
check the post titled Formulas.....these work perfectly for me...will help you choose a lens based on you length limitations.

note--I measure from the aperture---that's the best place to measure from (except for tele-lenses...which you measure from rear nodal point)...otherwise they have worked exactly and perfetly for me...these are also VERY good for LF enlarger calculations--with ceiling height limitations.

oh--see last posts where they actually ARE verified as very useful by the naysayers who don't like that I didn't include relativistic effects....

cyrus
1-Oct-2011, 15:21
Thanks
I am offered a Konica Hexagon GRII 260mm - any thoughts/tips?

johnielvis
1-Oct-2011, 15:56
that's pretty short for 11x14....you'll have HOW much room from aperture to subject?....twice that at 1:1 magnification...which is head and shoulders...that ain't much room....take you bellows divide by two and that's the max for 1:1....OR....extend the back OUT with a cardboard box...it works...and use a longer lens....LONG as possible is what I use.....that's why I gots a studio camera...and THAT ain't long enough for my tastes.

Paul Fitzgerald
1-Oct-2011, 16:23
"Thanks paul but how do you figure that my bellows draw limits me to 16"? Just interested in the math."

No math involved, I just measured the actual distance for each of the lenses listed.
21" bellows draw would give you 22" from the lens board to the GG. Just run down the list. These were focused at 5 feet, closer requires more and more bellows.

A B&L 16" Petzval converts to a 20" f/5 meniscus by removing the rear elements AND it's mounted 7" in front of the lens board, instant extension.

Formulas are nice for the optical distance but not the physical Flange Focal Length for each different lens :

Vitax 16"/3.8 = 23.25" (rear cell well behind flange)
Voigtlander Petzval 20"/5 = 24" (rear cell even with flange)
Dogmar 500/4.5 = 29" (mounts mid-barrel)

Have fun with the hunt.

cyrus
1-Oct-2011, 17:17
Well, supposedly the 260mm Hexagon GRII covers 11x14 at infinity with no movements so I can use it as a really wide landscape lens. But I was hoping for something available and inexpensive for head/shoulders too.

johnielvis
1-Oct-2011, 17:22
well....can you take and use 1/2 of the hexagon (what's that---a triangle???)...yeah...when you shoot it that way, call it a konca triangle...anyways...if the front or rear cell screws out...you can get like double the focal length plus "soft focus" (blurry) action going on.....i THINK hexanon is a plasmat 6 element type..if so...1/2 lens works...but you STILL need the bellows extension...or an extended mount on front or the cardboard box on back...try it.....1/2 lens and cardboard box

cyrus
1-Oct-2011, 17:50
LOL - my mistake - hexaCon not hexaGon...

There are a couple of posts here 'n there (one by Jim Galli) saying that the 260mm Hexacon does cover 11x14.

The lenses on Paul's list are a bit beyond my budget! using a box or a tube is also beyond me since I don't have the technical skills to make em. I guess the idea of a box is to basically build an extension that attaches to the rear of the camera?

I have a 21" Kodak anastigmat. Hmmm.. I wonder what happens if I remove a cell...

Anyway, I guess I should have been clear that I was thinking of the Hexacon as a landscape lens. "Just for fun" (to quote my late father who was an engineer) lets say it should cover 11x14 at infinity. At infinity bellows draw is the same as focal length, which for the 260mm Hexacon means a bellows draw of 260mm=10 inches.

For 1:1 it would be double that: 520mm or 20 inches, which is just shy of the max 21" bellows draw on my camera.

Now how far away would your lens have to be from your subject to get 1:1 magnification using a 260mm lens and a max bellows draw of 21"? What was the formula for lens to subject distance etc etc? My math is rusty! So I think the formula was 1/f=1/u +1/v where f is the focal length, u is lens-to-subject distance and v is the lens-to-film distance (aka bellows draw.) (Yes this formula is an approximation for a simple lens etc - lets just pretend that's the case)

So we have 1/260mm = 1/u + 1/520mm, eventually arriving at u=520mm or 20 inches.

So in other words, to get 1:1 magnification using the Hexacon the lens would have to be 20 inches away from the subject? Is this right?
For a 310mm lens, it would be 29 inches. But then I couldn't focus on infinity anymore.

Anyway doing the math, it turns out my Anastigmat 21" is a bad deal because of the limited 21" bellows draw on my camera. It can focus on infinity only at full extension. And, it can't focus on anything closer, because it would need greater than max extension. In theory, However then you have to consider the DOF of this lens. That's more math.

Fotoguy20d
1-Oct-2011, 19:43
No idea if it'll cover 11x14 (I've read that it covers 8x10) or what it's performance would be if it does cover (for that matter, I have yet to use the lens), but I have a B&L 508mm f5.6 Tele-Anastigmat (some sort of aero mapping lens I believe). Because it's a tele, it needs less bellows draw. There was a seller on ebay who had a few of them for around \$35 - some marks on the glass, and the aperture is iffy. And, its a big heavy thing so you either need a robust front standard or a brace.

Dan

cyrus
1-Oct-2011, 19:52
I wonder what lens was on my llx14 Empire State originally. The lens hole seems bit small...

Louis Pacilla
1-Oct-2011, 20:27
I wonder what lens was on my llx14 Empire State originally. The lens hole seems bit small...

Probably a B&L Protar series VII, V ,IV or something like that.

cyrus
1-Oct-2011, 21:31
*Sigh* too late in the night to be doing math

johnielvis
1-Oct-2011, 23:43
late it is...but look at my post with the formulae you need and you won't have to keep doing all them calculations...particularly formula #2 for bellows draw

the forumua is s'=(1+M)*f

so knowing focal length f and the magnification you want is EASY to get the bellows draw (including distance to aperture/rear nodal point) you need...this is EXACT if measured to rear nodal point--which is pretty close to aperture in almost all cases and for LONG bellows, the amount your off in any case is tiny compared to the bellows you're drawing (percentage wise).

OH.....for 1:1 type magnifications, all lenses have the same depth of field....in fact, the longer lenses kind of have "more"...more front focus dof....I doubt you notice this with portraits....it's due to the changes in magnificaiton---a shorter lens has it's magnification change faster than a long lens with subject depth....don't bother with all that...just know that depth of field is pretty much independant of focal length at 1:1 regime.

cyrus
1-Oct-2011, 23:54
Thanks Johnielvis - the problem I'm having now is finding a darn lens that I can do 1:1 with, but which draws 21" bellows, and which lets me keep the lens out of the subjects face (say, lens about 5 feet away from subject)
If anyone can solve THAT one, I'd be grateful!
Oh, and the lens should be relatively light not a monster, and it should not be rare as hen's teeth and cost about the same as a car.

OTOH I may try to extend the camera - add an extension to the track front and get a longer bellows . . . focusing would require really lloooooooooooong arms

johnielvis
2-Oct-2011, 00:31
yeah...you need a long camera--you want 60" at 1:1--you need 30 inch lens..... a mangnification of .5 gives you a pretty big field...much larger than head and shoulders so you'lll want to be using beween 1:1 and .5:1 range for 11x14.

you can get longer bellows for your camera or make an extension back--that is the best way---large cardboard box like I said...just use your camera back maybe for starters---huge box (black foam or dark corduroy or something on the inside)...tape the back to one side of the box and the lens to the other side--voila...focus by moving the whole contraption back and forth...you got a portrait camera.

distance to subject is (1 + 1/M)*f....

total distance is (1+M)*f + (1+ 1/M)*f = (2 + M + 1/M)*f

so if you want 60" to subject, you're working with 60" = (1+1/M)*f.....got a 21" lens, this gives 60" = (1+1/M)*21" OR M = .538....this gives you a viewing field of 11"/.538 by 14"/.538 OR 20.4" by 26.0"

the bellows for this is (1 + .538) * 21" = 32" about.....so get a 2 boxes...like 16x16x16 and put them together oblong to get 16x16x32 and you're in business with the 21" lens---special purpose camera--just tape the back on one side of the box and the lensboard on the other side...you'll be surprised how rigid it is...and easy to focus up and back..you'll need a table to put it on to slide it back and forth...but this will probably get more use than anything else you got if you like it....easily portable and you don't care if it gets wrecked (other than the back and lens).

cyrus
2-Oct-2011, 06:50
The rear extension box is probably the quick n easy way to go to make this into an 11x14 portrait camera. (I have an old Century 10A studio stand that cranks up and tilts 'n everything.) I think a 10" box to start with, gives me a bellows of 31 inches. Question is how to build the box. I don't have woodworking tools or knowledge & I'd want this to be a permanent thing instead of carboard because I'd hate to put weight on it with a holder containing a sheet of wet glass and watch it collapse & fall off. I'd need at a min. a table saw and one of those thingies that makes wood thinner...oh and a plaid flannel shirt and a beard...