Depth of field. Large format compared to 35mm.

I am considering moving up to large format. I was told by a friend that it's more difficult to

manage the depth of field on a 4x5 or an 8x10 than it is on a 35. Is this true? She was

saying that 2.8 on a 35mm portrait lens is much sharper than a 2.8 portriat lens on a large

format camera. She was saying that I'd have to shoot at f8 or above on the large format to

get the quality of 2.8 on a 35. Any truth to this?

First of all, there are no (modern) portrait lenses for large format with F2.8 maximum aperture. The fastest lenses are generally F5.6 and even they need to be stopped down to at least F/11 preferably F/16. The maximum aperture is just for making it easier to compose and focus.

 

If a 35 mm portrait lens has a focal length of 85mm, the corresponding 4x5 lens would be about 250 mm. To get similar depth of field (as 2.8/85) with that lens would require an F stop of about 8. For 8x10, the focal length would be about 500 mm and F stop about 16.

 

Narrow depth of field is a problem with all large format cameras. That is why they have the movements, to be able to position that narrow field of sharpness to its ideal position in the image. And that is also why most of the lenses stop down to F/64.

 

35mm lenses are generally sharper than large format lenses. But because of the very much larger film area, and thus much smaller need for enlargement, the quality of large format images, even from old lenses, is much better than anything possible from 35 mm format.

I would not say it is harder to manage. Large format gives you larger control by allowing you to have all the background or much less by the aperture control.

the easiest way to understand the properties of optical enlargement is with the aid of an enlarger.

 

if you place a neg but only enlarge it to 4x5 your aperture doesn't have to be that small, the larger you go the smaller the aperture may be required but that is a flat field issue.

 

On the field at any aperture your subject is always sharper than the background and because the lens sits farther from the film plane in LF the beam is somewhat compressed proportionately to the distance from lens to film plane and the enlarged distance between the diagonals of the picture.

 

at infinity all is apparently sharp with lens wide open and at macro

you'll be lucky to get .5 mm D.O.F.

 

This is not a limitation but a tool that can be used to control the appearance of your images.

 

LF cameras also have movements to further enhance this/ correct it entirely or exaggerate it for creative purposes.

 

If you consider D.O.F as a benefit and you are scared that shallow D.O.F can be a lesser quality then don't worry when people use a tripod they can do long exposures and when they don't and need the D.O.F they can use fast films and then push them because in the end you will get less grain than with a 35mm withouut any push and then there are neg films which have no grain.

Ignoring movements, you'll get the same DoF on 4x5 at f/11 than you would on 35mm at f/2.8 (4 stop difference) (for the same angle of view) (assuming that the subject is far enough away).

 

I wouldn't discount the absolute resolution of an LF lens at f/11 against a 35mm lens at f/2.8 - but don't forget that you'll have 4 times as much film, so even if your LF lens had only a quarter of the resolving power of the 35mm lens you'd still record as much detail.

 

BTW, as some others said, few LF lenses are faster than f/5.6 wide open.

Btw.: all the above said also means you need more ligth.

 

-either more sensitive film

 

-or longer exposure time

 

-or more sun or flashlight

 

Quite obvious: you have to initate the silver-halogenide reaction in far more emulsion.

 

I'd oppose to the term quality with your 2.8/35 calculation for I know some dudes searching the short DOF only available with 8x10 and at least 360mm wide open (meaning 5.6). Used in an artistic way the decay of focus makes a wide open 105/2.5 35mm Portrait lens look booring sharp.

 

regards

Martin

I disagree with some of the things that Jean-Baptiste Queru has stated, most notably the area of the film. There is roughly 14 times the area of film in a 4x5 image as in a 35mm shot, not 4 times the area.

 

There are specialist portrait lenses available for LF cameras with variable sharpness and bokeh, depending on the aperture used. Cooke has one model currently available. The effects these lenses have on image quality can't be reproduced in any 35mm lens.

 

You can't simply compare 35mm photography with LF photography: they are tools to be used for different purposes. LF is best suited to high quality images of static or predictable subjects, while 35mm photography is best suited to fast moving subject where hand holding the camera is an advantage.

 

So, what is your preferred subject? Which tool is best for the work you do?

Today LF cameras are almost always used on tripods. This restricts the subject matter. Landscape and architecture are popular uses. Portraits are possible, but not photos of sports action, etc.

Handheld 4x5 is possible and was widely used for press work in the past, but isn't as common today.

 

There are very few f2.8 LF lenses available, and only used, and more importantly, rarely would the depth of field be acceptable from a 150 mm f2.8 lens on 4x5. While some photographers want limited dof for their artistic purposes, e.g., to have only a person's face in focus and their ears and background out of focus, in most circumstances most photographers would want to stop down a lens on a 4x5 camera well past f2.8.

 

A typical maximum aperture for a LF lens is f5.6, and typical apertures for taking a photo are f16 to f32. To someone mostly experienced with 35 mm cameras, f16 may seem very slow, but since the camera is on a tripod, usually the compensating longer exposure isn't a problem. Of course, photograhing a moving subject in dim light won't be possible at f22.

 

Comparing sharpness of 35 mm vs 4x5, even a decades old, good quality LF lens that can be bought cheaply on ebay will beat the best 35 mm lens -- this is with the lenses used at their optimum apertures, which will be different, and for the same print size. Some will argue the superior resolution of 35 mm lenses in line pairs per mm, but 35 mm lenses aren't four times sharper than 4x5 lenses, so the print from the 4x5 negative will be sharper.

 

The improved sharpness with larger format goes roughly linearly with format dimension. A large format will also have reduced grainess and smoother tones, probably this goes roughly as the area of the formats.

 

Cameras are tools -- the best tool for a job depends on what the job is. I mostly use my 4x5 camera, but where tripods aren't allowed, or time doesn't permit, or the subject is moving too quickly, I use a smaller format.

 

Besides the technical differences, the "doing" of LF photography is different from 35 mm. You have a much larger image on the ground glass to compose with, and to check the focus and depth of field. Normally the LF photography spends more time on each photography,

studying or comptemplating the suject,

making fewer photographs but with hopefully a higher fraction of keepers.

 

Which you will like best depends on what you want to photography and which style of photography you prefer.

 

You mention "portrait lens" -- does this mean that your main interest is portraits, or is this just an example that your friend used?

I happen to own a 150 mm Xenotar f 2.8 with a lot of fine cleaning marks on the front glass. This works as a fast, albeit somewhat low contrast portrait lens. It covers the 4x5 format. It is very useful, for instance, in a Linhof Technika with matched cam and it can, if I put my mind to it, be used fully open with a rather narrow depth of field.

Your terminology is a little sloppy. LF lenses are just as sharp as small format lenses. All things being equal.

 

Depth of field is a function of the size of the image on the film. If you make a full-frame shot of a teacup on 35mm, it will be 3/4" high on the film. A full-frame shot of the same cup on 8x10 will turn out to be a 4X lifesize macro shot.

 

Like so many 8x10 still lifes, you will have difficulty holding focus between the front and back rims of the cup. But so would be the case with 35mm if the cup's image was projected to the exact same size on the film.

Hmm? Generally 35mm lenses are SHARPER than large-format lenses, because they have to be. a 35mm film frame has to be enlarged about 10x to make an 8x10 print; an 8x10 film sheet doesn't have to be enlarged at all. To get equal resolution (not the same as sharpness, of course, but related) on the print, the 35mm lens has to have 10 times the resolving ability of the lens used on the 8x10 camera. A "very good" 35mm lens can resolve 100 lp/mm in the center of the image; A "very good" large format lens often can't do better than about 65 lp/mm - but its image is still MUCH better on a print of the same size.

Martin: I agree, emulsion speed is a problem. In 35mm the reason is often to reach hand-holdability. I find that with the small apertures often involved in LF (I can't remember ever shooting wider open than f/11), the shutter speeds you'd need to reach good sharpness hand-held (at those focal lengths, I'd go for 1/250s or faster on my 35mm gear) and the weight of the equipment, for me the notion of film speed becomes irrelevant. With the camera on a tripod I found that ISO 100 (or 160) was always "fast enough".

 

Graeme: I count film sizes linearly, not in surface, and for portraits I count the width of the film (95mm for 4x5, 24mm for 35mm), which explains the difference. I do that because just about everything else in photography is counted linearly, including resolution measurements (local measurements in lp/mm and global measurement in lph).

 

Bob: it depends whether you measure absolute aerial resolution (35mm lenses will most likely win there), absolute resolution on film at the optimal aperture (where 35mm is typically film-limited and LF is close to being film-limited, therefore the difference isn't that big), absolute resolution on film for a given shallow depth of field (where 35mm will likely have to be shot closer to wide open, giving more opportunities for lens aberrations to show their ugly head), or whether you measure global resolution (i.e. the total amount of detail that gets recorded on the entire image) (where LF wins hands down).

"Btw.: all the above said also means you need more ligth (sic)." "Quite obvious: you have to initate the silver-halogenide reaction in far more emulsion."

 

Hmmmm...this is totally meaningless, and not even technically correct. I shoot 35mm, 120, and 4x5 Provia. Quite often of the same subject with the same lighting setup. Funny, the exposure is always the same for all of the formats - even though by your statement something different should happen. I guess, over the past 40 years of shooting large format, I must have missed something. Could you explain how this works in detail?

 

"Portraits are possible, but not photos of sports action, etc. Handheld 4x5 is possible and was widely used for press work in the past, but isn't as common today."

 

Sports and action photos aren't possible today with 4x5 but they were common in the past? Say what? The only thing that's stopping someone from being WeeGee is just not picking up a 4x5 press camera and hand holding it - the technology still WORKS.

 

Your friend's points are technically correct, but really not germaine to the use of a 4x5. They are totally different pieces of equipment. It's a bit like comparing a dump truck to a sports car. What's the point?

 

The "quality" statement is hilarious. F-stop has nothing to do with "quality." You can't find a 4x5 lens with an f/2.8 opening - so the point is moot. There is no comparison. If you have to shoot at f/8 or above - so what? That's part of using a large format camera.

 

Ask your friend about having a 20x24-inch or larger print made from 35mm and one made from 4x5 - then have her explain "quality" within that context.

 

Basically, you have more control over depth-of-field and sharpness with a 4x5 than you do with a 35mm camera. Put a 150mm lens on a 35mm, put a 150mm lens on a 4x5. On a 35mm the lens is a telephoto. On a 4x5 it's a "normal lens" (approximately equal to a 50mm on 35mm film for field-of-view).

 

The depth-of-field on both lenses will be the same. But, you will be able to have much more control of the depth-of-field on the 4x5 because you can use front lens tilt (Scheimpflug) corrections.

 

A portrait lens is any lens you want to use for a portrait. For formal portraits, I like a 210mm on my 4x5. On my Hasselblad I like a 120mm. On a 35mm I like a 105mm. But, with informal portraits - anything goes. I've seen 17mm lenses used effectively on 35mm for portraits.

 

Why do YOU think you want to change to 4x5? What advantages would the different format bring to YOUR work? Maybe, you really don't need 4x5, maybe medium format would be a better choice, or perhaps 35mm is perfect. What are you trying to achieve with the final image?

 

Those are the real questions to answer. Once you answer those questions the correct choice will become much clearer.

Jean-Baptiste,

you can 'count' film how you like, it won't change the difference in size between a 35mm frame and 5x4 sheet; that is a ratio of 875:12500, or roughly 1:14.

(by the way, 4 inches is not 9.5cm)

 

To answer Gerald's question, it *is* harder to control DoF on LF compared to 35mm, but you get far greater control over it on the larger size. Your friend is rather confused to try and equate shooting at F8 on LF to shooting at F2.8 on 35mm, without being clear of her definition of 'quality'.

 

Rather than read a load of sometimes conflicting comments on the Internet, you really can't beat trying it out for yourself - see if you can get your hands on a camera, preferably with someone to guide you. Many of the points made here will then be far more meaningful. If you gave a hint where you are located, who knows, someone on here might live nearby?

According to an online DOF calculator, the near and far limit of acceptable sharpness for a 70mm lens at f5.6, in 35mm format, is 7.39ft and 8.71 ft for a subject focused at 8ft away. So the total DOF is 1.32 feet.

 

Figure a comparable lens in 4x5 is 210mm. The near and far limit of acceptable sharpness, at f5.6, is 7.78ft and 8.24ft for a total DOF of 0.46 ft.

 

Also check out www.largeformatphotography.info

 

The technical aspects of large-format photography are a couple orders of magnitude in terms of difficulty and speed.

Depth of focus depends on the circle of confusion you choose. You would normally use a much larger circle of confusion for larger format. (Remember, less lines/mm on large format film.) So you might use a 4X larger one on 4x5 as on 35mm. (Or less.) What really matters is the circle of confusion on the print, of course.

Mark: I'm not arguing that the surface is much larger - that's a fact. I'm just saying that I find it more natural to count in linear units, and that I believe I'm not the only one (even f-stops are measured in linear units even though physically it would make more sense to measure them as a surface).

 

Just like an image on 35mm film isn't 35mm high (it's 24mm), an image on 4x5 film isn't 4 inches high, the actual image size is almost exaclty 95x120mm.

Hello,

Hey I was (changed business persuits)large format shooter for 30 years.

Maybe G means "acheive" when he states "manage" DOF.

Here's what I know (debateable) about DOF.

DOF is the same (some tolerance accepted) at any given f/stop if the image sizes are identical if no camera movements are used.

The focal length of the lens(s) is not relevant.

And a bit more not concerning DOF.

F/11 on LF requires the same amount of light as f/11 on 35mm as long as the same emulsion speeds are used and neither camera has had bellows factors introduced.

I do get confused when statements are made that to get more DOF/sharpness you must use an f/stop above f/8 (for example). In actuality you will need to use an f/stop BELOW f/8 (i.e. f/16)

F/stops are an abbreviation of a fraction. F/16 should read f/1/16.

<I>I was told by a friend that it's more difficult to manage the depth of field on a 4x5 or an 8x10 than it is on a 35. Is this true?</I><P>

<B>Yes.</B> Everything is more difficult with large format cameras. That is the initiation fee that you pay for stunning images.

Just to be contrary:

 

"I was told by a friend that it's more difficult to manage the depth of field on a 4x5 or an 8x10 than it is on a 35. Is this true?"

 

No. It's far easier to get blurred background with LF - moreover it's far easier to control the amount and placement of the blur with LF. Here's an example of something that's easy with LF, impossible to manage with 35mm.<div></div>

There's an old saying:

 

"If you're shooting a picture of a girl without her clothes, in 35mm format, that's porn.

 

If you're shooting a picture of a girl without her clothes, in Large Format, that's art."

Man, it's going to hit the fan if the Leica folks get wind of the "large format lenses are sharper than 35mm lenses" thing.

 

If anyone needs me, I'll be in my changing bag.

Not the lenses, but same-size prints.

<I>You can't find a 4x5 lens with an f/2.8 opening - so the point is moot. </I><br><br>Hell why mess around with a wimpy F2.8. Just use a F2.5 Aero Ektar; like a mess of folks used post WW2 on 4x5 speed graphics. They were only 5 dollars used. America had many machine shops then; and making you own gear and manufacturing were acceptable. There was alos the fast F2.8 Xenotar; some a fast F2.5 153mm Aero Ektar; a fast F1.5 Fluro Ektar. I used a lighter F3.5 210mm xenar for sports; and the radically heavier 178mm F2.5 Ektar too.<BR><BR>What has happened is that the press doesnt used 4x5 anymore; film pack died about roughtly 1980. Large format users got old; frumpier; scared to shoot any sports at all; even if for fun. LF 4x5 users thus use more tripods than the press chaps decades ago. LF users have gotten old;t the cameras slower; film pack dissappeared; now they are more of a landscape camera; and little if any used by press users.

<img src="http://d6d2h4gfvy8t8.cloudfront.net/1387989-lg.jpg">

Kelly, your 7"/2.5 AeroEktar is a tiny little lens of nothing at all. You should have seen the 6"/1.9 Dallmeyer Super Six that I bought a couple of years ago. I had visions of having it mounted on a 2x3 Pacemaker board and using it on my little 2x3 Speed. Not a good idea for shooting hand-held. I later sold the lens. Outrageousness is nice, but it turned out to be worth much more to a collector in Japan than to me.

 

To get back to the original topic, Gerald, generalizations like the ones your friend made aren't always true. I've shot a well-respected macro lens for 35 mm, viz., a 200/4 MicroNikkor AI, against a process lens that's sometimes used as a taking lens on LF cameras, to wit, a 210/9 Konica Hexanon GRII. At 1:2 and ~ 30 feet, at f/8, f/11, and f/16, on EB the GRII beat the MicroNikkor. So it isn't always the case that a lens for 35 mm still is sharper than a roughly equivalent lens for LF.

 

Cheers,

 

Dan