What lens to get for most shallow depth of field on 4x5?

[Oslolens]

I have a 150mm Xenar D f3.5 If you need shorter focal length, it is possible to add a close-up filter. The Nikon and Canon are best

Sent fra min SM-G975F via Tapatalk

[Bob Salomon]

You are absolutely right - I am not! Thanks

You can also manipulate DOF by your image placement, pulling the subject away from the background or from the foreground, or both.
Applying some tilt and/or swing can play with DOF and, of course, using a longer lens to minimize DOF.

Are you doing people or things? If people the foreshortening of short lenses like your 50 could present more of a problem then your DOF.

[Arne Croell]

I am currently using a "fullframe" digital camera in combination with the fastest lens in consumer market, the Mitakon 50mm f/0.95. So for me to call a lens "super fast" it has to have a 35mm equivalent aperture below f/0.95.
If we compare the diameter of the 4x5 format (153.7mm) to the one of 35mm film (43.3mm), 4x5 has a crop factor of 0.28. So the lens should have at least a maximum aperture of f/3.4 and focal length of 178mm to produce as shallow DoF as the Mitakon does on fullframe.
I like to shoot wider than 50mm (to be honest, I don't really like the look of a 50mm lens on 35mm), so the focal length should be around ~140mm to ~100mm. To get most shallow DoF I will probably only consider lenses with a maximum aperture larger than f/3.2.

Initially I only looked at 8x10 because this format has a really crazy crop factor of 0.14 with the potential of crazy shallow DoF. But cameras and film just get so much more expensive, and cameras become quite heavy.

Thanks for all your lens recommendations, I will check which one fits onto my 4x5 camera of choice (Chamonix C45F-2).

In the 100-140mm range, you likely won’t find 4x5” lenses with openings larger than F/3.5. Essentially, 135mm f/3.5 is the only combination I can think of, either as Schneider Xenotar, Zeiss Planar, or Zeiss Jena Biometar.

[Corran]

I am currently using a "fullframe" digital camera in combination with the fastest lens in consumer market, the Mitakon 50mm f/0.95. So for me to call a lens "super fast" it has to have a 35mm equivalent aperture below f/0.95.
If we compare the diameter of the 4x5 format (153.7mm) to the one of 35mm film (43.3mm), 4x5 has a crop factor of 0.28. So the lens should have at least a maximum aperture of f/3.4 and focal length of 178mm to produce as shallow DoF as the Mitakon does on fullframe.
I like to shoot wider than 50mm (to be honest, I don't really like the look of a 50mm lens on 35mm), so the focal length should be around ~140mm to ~100mm. To get most shallow DoF I will probably only consider lenses with a maximum aperture larger than f/3.2.

Initially I only looked at 8x10 because this format has a really crazy crop factor of 0.14 with the potential of crazy shallow DoF. But cameras and film just get so much more expensive, and cameras become quite heavy.

Thanks for all your lens recommendations, I will check which one fits onto my 4x5 camera of choice (Chamonix C45F-2).

Firstly, many options (especially affordable ones) have no shutter, which means you won't be able to use them on that camera, unless you are shooting longer exposures. But with a fast lens, I'm guessing you need fast exposures, if you are shooting in any kind of daylight. Secondly, the options in shutter, often have limited fast shutter speeds, so that also becomes an issue. The 150mm f/2.8 Xenotar, when I had it freshly CLA'd, only could shoot 1/125 at it's fastest setting (marked 1/200, but LF shutters generally don't get to their marked fast speed).

Also, 150mm is pretty much the shortest lens you are going to get with those kind of apertures, at least with full film coverage. As Arne mentioned, the 135mm f/3.5 lenses available are about as fast as those focal lengths get.

I recommend you first consider buying a Speed Graphic with working FP shutter, and then consider what you want to spend. By the way, the very popular Aero-Ektar lens comes in a 6" or 152mm length, which will be a bit "wider" than the more common 7".

And if you don't mind a little bit of vignetting, a really interesting option will be the Schneider Gottingen 12.5cm f/2 Xenon. This lens is pretty rare and covers a bit more than a 3x4 inch sheet of film, so certainly has nice wider field of view on 4x5 if you don't mind some black corners.

Regarding your 35mm "equivalents:" Along with the different aspect ratio, LF depth of field simply looks a little different, and in my opinion shooting even at f/4 or f/5.6 can give a very pleasing amount of focus with a stark difference from in focus to out of focus, so don't get tunnel vision looking for the fastest aperture ever and only shoot there.

[scheinfluger_77]

All else being equal, you can generally assume that longer lenses and shorter focusing distances will also give a shallow d-o-f. This is a rule-of-thumb practice. Each lens has its own characteristics, and personal experimentations are the only way to put this subjective phenomenon into practice. Strict focus on lens physical characteristics is only part of the story.

[Dan Fromm]

Hmm. 6"/1.9, also sold as 150mm/1.9, Dallmeyer Super Six. Unobtanium, unshutterable. I had a 6 incher, sold it on because it was valuable and unusable with any camera I was likely to have.

8"/2.0 Super Six. 200/2.0 S.F.O.M., some were engraved Kinoptic as well. I had one, a real dog (poor condition) not engraved Kinoptic. Highly superior desk weight. Unshutterable.

But remember that depth of field is controlled entirely by magnification and aperture. If high magnification doesn't make sense for the image, all that's left to get narrow DoF is a fast lens shot wide open.

The OP might do well to use a format smaller than 4x5, and for several reasons. High aperture lenses for 35mm still are abundant, not too heavy and not too expensive. High aperture lenses for larger formats, even 6x6 (that's most of the 6"/2.8 Elcans on the market, their serial numbers start with 138; 6"/2.8 Elcans that cover 4x5 have serial numbers starting with180 and are very scarce), are larger, heavier, less common and hard to put to use.

[dubiduck]

So I guess for very shallow depth of field nothing compares to 8x10 (or even larger)?

[Bob Salomon]

So I guess for very shallow depth of field nothing compares to 8x10 (or even larger)?

No, it depends on your lens, your aperture and the magnification. Not with film size.

[dubiduck]

Sure, but given the fact that a larger film size will show you more of the scene (e.g. imitates a wider focal length) you have to get closer to the subject leading to a greater magnification leading to shallower DoF. And because some lenses, which cover 4x5, also cover 8x10, you get that f/5.6 @ 8x10.

[Dan Fromm]

So I guess for very shallow depth of field nothing compares to 8x10 (or even larger)?

For the same image (subject and framing) shot at the same aperture, the larger the format the shallower DoF will be. This because filling the larger frame requires more magnification.

So, OP, decide how large you want to print from 4x5. This will give you the Circle of Confusion needed to calculate DoF given magnification and aperture. Decide how large the subject you want to image on 4x5 is. This will give you magnification. Then crank up your DoF calculator and play around to get the aperture that will give you the DoF you want.

Tedious, and you'll have to do the exercise every time you change the subject's size. But that's what you'll have to do. No simple rule of thumb will guide you well, you have to do the arithmetic.

Don't be a piker. Go to 16x20.