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Scott --
22-Jun-2007, 17:50
Hi, all -

I'm still in planning/design stage on a camera project (one that's blossomed from 4x5 to 5x12...), and have a basic, rank noob question: In older wooden field cameras, how was front tilt implemented? I found this example (http://www.largeformatphotography.info/forum/showthread.php?t=26299) (and subsequently posted patent), but was wondering if there's a more straight-forward, less clunky approach. A mechanical engineer, I'm not. My visualizing is hampered here.

I'm debating the pros and cons of the old folding bed field cameras (like my Seneca) versus the Deardorff/Ebony style of telescoping beds. The folding bed design seems much simpler to implement, but that dadgummed front tilt throws a wrench in the works. And I think I could fake the front tilt using rear tilt, tripod head tilt, and front rise, but I'd rather not have to do that.

Anyone care to help me out? I'd appreciate it.

Thanks,
Scott

Nick_3536
22-Jun-2007, 17:55
The folding bed design seems much simpler to implement, but that dadgummed front tilt throws a wrench in the works.

Why do you think tilt throws a wrench? :confused:

Scott --
22-Jun-2007, 18:11
'Cause I can't picture how to design it into the wooden front standard. I'm sure it's been done; I haven't seen it (noob), and my engineering creativity always tended toward chemical...

Colin Graham
22-Jun-2007, 18:27
Hi Scott, you can make it a simple as a pivoting knob that tightens which controls both rise and tilt, or use separate knobs for rise and tilt, all depends on what you want. For larger formats and heavy lenses I'd recommend separate controls. Here's what I did on mine. The top knob is centered on-axis for tilt, bottom knob is rise. The tilt bearing plate (outside) is like a tee nut that rides in the compound slot but doesn't tighten against anything but the rise bearing plate (inside), which does tighten against the main slot. Sounds confusing, but it's pretty simple.

David A. Goldfarb
22-Jun-2007, 18:31
A simple solution for front axis tilts is to have the front standard as two upright pieces with channels running vertically. The front frame has two bolts running through the channels, and there is a knob on each side that control the rise/fall and the tilt or alternately a T-nut in the lensboard frame and a bolt running through the channels. With such a system (Gowland cameras work this way), you set the rise/fall before the tilt. If you want to separate the rise/fall from the tilt, it gets more complicated, as in the linked thread.

Ernest Purdum
22-Jun-2007, 18:33
The simplest way to do it is by an axis tilt that just uses the nuts outside the uprights of the front standard to lock the tilt by friction. This is usually combined with something that serves as a zero reference, detent or lock. Maybe this seems too simple, but it gets the job done fairly well.

Another approach is a base tilt with slotted supports bracing the uprights after they have been set to the desired angle.

Jim Noel
22-Jun-2007, 19:31
Look up the F&S Universal 8x10. It has front tilts, as well as every other movement. The front tilt is done in a very straight forward manner.

John Kasaian
22-Jun-2007, 21:22
Also check out the Agfa Ansco Univesal----all kinds of movements on a flat bed woody!

Sandeha
23-Jun-2007, 01:46
I doubt you could make it much simpler than this ...

http://i10.photobucket.com/albums/a119/Sandeha/large_format/front_standard_lock.jpg

The bolt head is cut square and slotted into a brass spacer than fits flush into the wooden standard - it's held in place by the long brass plate and four screws.

The bolt slides up and down the slotted riser of the front standard support. It's held in place by the threaded brass knob which tightens it. The brass spacer/washer makes for more comfortable use.

This controls both rise and tilt together.

Ash
23-Jun-2007, 03:04
The Kodak I restored does the following -

One side, there is rise and fall. The bolt/knob for this goes through the supports either side (it's a U-bracket with the rise/fall panel inside). below this a second set of knobs, one either side for tightening.

The whole U-bracket pivots on the point of the top knobs.

The amount of tilt is determined by the metal brace that connects the U-bracket to the moving front standard base.

probably best seen in this photo:

http://i2.photobucket.com/albums/y43/second-belated/DSC00883a.jpg

This "before" photo shows how the tilt works

http://i2.photobucket.com/albums/y43/second-belated/DSCF0187-1.jpg

Sandeha
23-Jun-2007, 03:30
Ash, that's a neat system, but like many 'oldies' there's no option for front standard forward tilt. I'd miss that if I didn't have it.

Maretzo
23-Jun-2007, 03:32
Ask our friend Littman, he knows something about patents... :D

Ash
23-Jun-2007, 03:45
In fact it tilts forward. The metal bracket has a semicircle cut-out, and sits central when straight.

Depending on the shape of the cut-out and the width of the metal bracket, you can have extreme forward and back. Mine only gives a few degrees, however.


quick blurry one:
http://i2.photobucket.com/albums/y43/second-belated/DSC00405.jpg

With this particular camera there is a lot of movement on the rear standard, so any loss in front forward tilt can be made up for with the back, which has a huge geared tilt front and back

Nick_3536
23-Jun-2007, 04:02
On the Ansco the front standard stays put but the lensboard section tilts.

Think of it like two boxes set inside each other. The inside box is the lensboard section. The outer is the part that moves up/down for rise/fall. Both parts then ride up/down on the outer rails together.

Sandeha
23-Jun-2007, 04:59
Oh, I get it. So there is some front standard forward tilt, though less than tilting backwards?


With this particular camera there is a lot of movement on the rear standard, so any loss in front forward tilt can be made up for with the back, which has a huge geared tilt front and back

But it changes perspective if you rely on the rear for tilt.

Scott --
23-Jun-2007, 05:13
Ok, 'nother ignorant question, but this derives (somewhat) from reading Simmons: If the pivot for the rear tilt is centered on the rear standard (like the front ideally would be), is there still a perspective change difference when tilting the rear? My Seneca's set up this way, and Steve says something in his book about the lens-to-film plane distance changing with rear tilt. If the center of the film plane is the picot point, that shouldn't be happening, right?

Thanks for all the responoses, everyone. I'm starting to get a feel for how this should work.

Sandeha
23-Jun-2007, 05:19
The lens to film plane won't change at the pivot point, but above and below will. Eg. Tilt the rear standard backwards and the distance between the lens and the top edge of the film goes waay further back. (And the bottom edge gets closer to the lens.)

Is that what you meant?

Scott --
23-Jun-2007, 06:35
Yeah, but (according to Simmons, if I be readin' it right), the same principle on the front standard doesn't change the geometry. See why I'm confused?

eddie
23-Jun-2007, 06:42
Sandeha,
interesting design. can you posta pic that shows this on the camera and in use? thanks
eddie

BradS
23-Jun-2007, 06:57
Yeah, but (according to Simmons, if I be readin' it right), the same principle on the front standard doesn't change the geometry. See why I'm confused?


Moving the front (alone) never changes the geometry of the image because it does not change the relationship between the film and the subject. It only changes where the lens is pointing. The geometrry, the shape if you will of the image is only a function of the relationship of the back (the film plane) to the actual subject.
The angular movements of the back (tilt and swing) always affect the shape of the image.

Make sense?

Sandeha
23-Jun-2007, 07:14
Moving the front (alone) never changes the geometry of the image because it does not change the relationship between the film and the subject.

Esatto !! Scott, remember that you can focus by moving the front or the rear. But, swinging or tilting the rear will alter the proportions of the image of the subject - think, like, big head/small feet, or big feet/small head.

(Gee, I used to be so good at picking analogies!)

Scott --
23-Jun-2007, 07:32
Ok, the Seneca doesn't have front tilt, but does have rear tilt. Say I need some front tilt. Can I: (1) Tilt the camera down on the tripod using the pan tilt head; (2) Tilt the rear back until it's vertical, (3) Apply some front rise? Does that equal front tilt, or not?

Unrelated, I'm thinking right now I want to emulate the Korona design, but with front tilt...

Sandeha
23-Jun-2007, 07:49
Hope this helps.

Standard, neutral position:
http://i10.photobucket.com/albums/a119/Sandeha/large_format/th_IMGP3726_copy.jpg (http://i10.photobucket.com/albums/a119/Sandeha/large_format/IMGP3726_copy.jpg)

Forward for long lenses/macro:
http://i10.photobucket.com/albums/a119/Sandeha/large_format/th_IMGP3728_copy.jpg (http://i10.photobucket.com/albums/a119/Sandeha/large_format/IMGP3728_copy.jpg)

Back position for wide angles:
http://i10.photobucket.com/albums/a119/Sandeha/large_format/th_IMGP3729_copy.jpg (http://i10.photobucket.com/albums/a119/Sandeha/large_format/IMGP3729_copy.jpg)

Getting ready for bed:
http://i10.photobucket.com/albums/a119/Sandeha/large_format/th_IMGP3730_copy.jpg (http://i10.photobucket.com/albums/a119/Sandeha/large_format/IMGP3730_copy.jpg)

Sandeha
23-Jun-2007, 07:50
And finally, going bye-byes:
http://i10.photobucket.com/albums/a119/Sandeha/large_format/th_IMGP3727_copy.jpg (http://i10.photobucket.com/albums/a119/Sandeha/large_format/IMGP3727_copy.jpg)

BradS
23-Jun-2007, 07:50
Yes that achieves the same effect but it makes it difficult to focus beacuse moving either standard along the (tilted) focus axis causes that standard to also rise or fall. Try it, tilt the bed down and compensate by tilting the back to bring it to vertical....in this configuration focussing is like focussing and changing rise/fall simulaneously.

With regard to the pictured Korona: that one doesn't have front tilt or swing - does it?

Sandeha
23-Jun-2007, 07:52
Ok, the Seneca doesn't have front tilt, but does have rear tilt. Say I need some front tilt. Can I: (1) Tilt the camera down on the tripod using the pan tilt head; (2) Tilt the rear back until it's vertical, (3) Apply some front rise? Does that equal front tilt, or not?

In principle, yes. In practice, you'd need a lot of front rise. Might not work at all, though maybe with some wide lenses.

Paul Fitzgerald
23-Jun-2007, 08:00
" Say I need some front tilt. Can I: (1) Tilt the camera down on the tripod using the pan tilt head; (2) Tilt the rear back until it's vertical, (3) Apply some front rise? Does that equal front tilt, or not?"

Exactly, that's why most antiques have a pendulum on the rear body. This should supply all the front tilt usually needed.

Just to bust them: rear tilt doesn't just distort the picture as mentioned, it also engages the inverse-square rule on steroids and can drive you crazy. With front tilt the pivot point is the optical center (entrance node) of the lens and all is good. With rear tilt the infinite point of focus on the GG is the pivot point, anything from there to the bottom edge of the GG is now closer to the lens than inf., completely OOF and overexposed (the clouds). Anything from the inf. point to the top edge is farther away from the lens and underexposed (the foreground and shadows). Using rear-tilt can add 4 stops to the exposure scale and drive you crazy. Add in varying filter factors (by light type) and you see why photographer go bald, they pull their hair out.

Easier hobbies are for wimps, have fun with it all.

Ernest Purdum
23-Jun-2007, 08:16
Sandeha's examples show both arrangements of front tilt that I earlier described. They also show a fine example of the influence of Frederick H. Sanderson 112 years after he designed the first really generous view camera movements.

Sandeha
23-Jun-2007, 08:59
Sandeha's examples show both arrangements of front tilt that I earlier described. They also show a fine example of the influence of Frederick H. Sanderson 112 years after he designed the first really generous view camera movements.

You guys crack me up!

I always wanted something that was state-of-the-art ... only never mind when. :p

Edit: http://www.photogallery.it/storia/itailb.html

Ernest Purdum
23-Jun-2007, 09:49
Sandeha - perhaps you should avoid looking at eBay item 270135588374. It might extend the crack further.

I would have like to find an example showing all the tricks, but you'll have to take it on trust that this one can also be put into all the positions you nicely showed us.

Ole Tjugen
23-Jun-2007, 10:14
A couple more examples:

First two classic plate cameras - the first one has lots of front tilt and limited rear movements, the second one has only front rise&shift, and about 10 degrees rear swing&tilt: http://www.bruraholo.no/Cameras/Reisekamera.html

And another classic - the Gandolfi Traditional: http://www.bruraholo.no/Cameras/Gandolfi/Gandolfi.html