F/1.4?

I'm interested in extremely shallow DOF for landscape shots, something around a few feet in focus from a

distance of 100 feet. To get there I obviously need some really low f numbers. The smallest I've found is

the Schneider Xenotar's 2.8.

 

Is there some reason why we don't see a lens with F/1.4 in 8x10 photography? I played around with a

program called LensForge to see if I could just scale up a 35mm lens and it seems to work, but I'm no

expert.

 

Any suggestions for extremely shallow DOF are appreciated.

 

Billy

I'm certain a lens as you want could be made, but aside from the obvious expense, the weight would tax the mechanics of most cameras to simply support a piece of glass this size.

 

 

I'm getting this mental picture of a front standard operated by hydraulics, rope and tent stakes and ...

Subject to the nature of the scenes you'll be shooting, have you considered the idea of movements to restrict DoF instead?

"Is there some reason why we don't see a lens with F/1.4 in 8x10 photography?"

 

Cost (think five figures, easily), size (front element would be enormous), and - most of all - no demand. Fast lenses are generally for handheld and/or action photography, while LF lenses are generally for tripod-mounted photography in which MORE of the scene rather than less is generally wanted in focus.

 

I suppose if you put a relatively long, relatively fast lens on an 8x10 (e.g. Schneider 480/8.4), tilted the focus plane, and shot it wide open you could start approaching something of the effect you seek (according to Schneider the d.o.f. of a 480mm at f8 at 100 feet goes from 82 to 127 feet, though their CoC for 8x10 isn't specified).

 

But I'd shoot a smaller format.

Would a shift or tilt of the film standard or lens standard or both yield a similar result? Most of us are tilting and swinging to gain depth of field. Just tilt and swing in the opposite direction for less DOF. Seems logical. "Captain - that is not logical".<grin>

 

My 2 cents,

David

have you check out this

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00KY6L

There is no such thing as Depth of Field. There is (assuming no aborations)only one exact plane of focus. Everything else is just more or less fuzzy.

A long telefoto lens, moved in close will give you shallow DoF even with an F8 lens.

I used to have a 150mm f2.8 Komura (for 4x5). It wasn't as groovy as I thought it would be.

How about a 18"f3.5? Long focus and a fast aperature. Might not cover 8x10, but might work with a rebuilt Speed Grahic. There are five for sale on Ebay. Do a search for Beseler...

The short answer to your question is that super fast LF lenses are impractical; they would

be too expensive, wouldn't fit into a shutter, and would be too heavy. An 300mm f1.4 lens

would have a front element of over 8". Can you imagine the weight? Anyhow, with few

notable exceptions, the majority of LF work is done at smaller apertures.

 

That said, there are faster lenses than the f2.8 Xenotar. However, most are difficult to find

and are not terribly sharp. Of those out there, I have heard good things about the

Dallmeyer f1.9 Super-Six and of course the f1.8 Ernostar is legendary. There are of course

lots of aerial lenses which might fit the bill, however these are often too large for practical

use. I saw a 9" f1.5 Perkins-Elmer Aerial lens which would cover 9x9 (I think). It weight

more than I do.

I suspect DOF of an f/1.4 lens would be unusable for pretty much any practical purpose on 8x10. More to the point, you really don't see leaf shutter lenses faster than f/2.8, and there are probably sound mechanical reasons for this--like the aperture gets physically too large.

Have had much success using a shutter mounted Wollensak 75mm f/1.9 Oscillo-

Anastigmat lens on a Galvin 6x9 view and then scanning the 120 negatives. Using a ND

filter in front of the lens enables me to shoot in dayight with the shutter's fastest speed of

1/125. A year or two ago, you would see this 75mm Wollensak lens on Ebay being won for

less than $50. Mine I think cost me less than $25... great buy. Also have tried using the

lens off an opaque projector on an 8x10, f/stop was quite large and was easily put in front

of an older Sinar shutter, but didn't have a ND filter large enough to use for daylight

exposures and the whole rig was just too makeshift to pursue the project. The 6x9 Galvin

with 75mm f/1.9 lens is so much more compact & user friendly.

Greg

Theres a Goerz F:2 on ebay still I think::

The largest "common" shutter is the Compound 5. Two lenses you can find in this shutter are Schneider 300mm f:4.5 Xenar and 360mm f:5.6 Symmar.

 

Anything bigger than that and you need some other kind of shutter arrangement - like aa Packard shutter, or mounting a Speed Graphic between the lens and the film. :)

Bill Mitchell, Sep 19, 2007; 05:31 p.m. wrote

"There is no such thing as Depth of Field. There is (assuming no aborations)only one exact

plane of focus. Everything else is just more or less fuzzy."

 

Huh? You do have the right name for the "plane of focus". However, the rest of the world

(i.e. everyone but you) agrees that DoF exists. It relates to which "fuzzy" parts are

*perceived* as being as sharp as objects exactly in the plane of focus, based on how the

image is viewed.

 

Billy, Just check out what David suggests (reverse tilt)

Here's an example of a "weird" plane of focus from a tilt/shit lens

Here is the Challenge and Solution as proposed from TOYO. "Selective Focus Challenge: You want to focus on just one leaf or flower and leave everything else in the scene a soft blur. Or, you want to recreate an effect you may have seen in a fashion magazine where only the model's eyes are sharp, and all the clothes are softly blurred.

Solution: Front Tilt-Backward can be used to accomplish these selective focus effects with ease. Front swing can be used for a similar effect with objects to the left or right of your composition center. Swinging in either direction will bring objects in or out of focus."

To achieve the bokeh focused @ 100' will require a relative long telephoto anyway, and a fast telephoto at that. It seems the f1.4 lens option would be no different from that of a camera with no perspective controls. I prefer to use the effect only a view camera can yield. I would opt for the front tilt-back with any assortment of existing lenses. With this you can control the exact degree of bokeh desired.