technical or medium format and narrow depth of field

[ibear88]

Hi, there may be an obvious answer to my question, but I searched the medium format forum and could not find it, so here I am.

When looking at the "fun with" threads, I notice that technical camera images generally are very sharp and often include, I assume, some tilt to obtain very deep depth of field. The detail of such images is stunning.

Back in my 4x5 film days, I also liked to make images of very narrow depth of field too. I don't see that among technical camera images. Its quite possible I've missed them or I'm not looking in the right place. But, is there an optical or other technical reason that a technical camera with a digital back may not be suitable for narrow depth of field?

thanks, Jeff

 

[Shashin]

Because, like with 4x5, lenses are optimized to f/11. Maximum aperture for most lenses is f/5.6. Also, most technical camera users are interested in landscapes, which has a preference toward a greater DoF.

 

[Jorgen Udvang]

Because, like with 4x5, lenses are optimized to f/11. Maximum aperture for most lenses is f/5.6. Also, most technical camera users are interested in landscapes, which has a preference toward a greater DoF.

+1 to that. Just let me add the obvious: Since the digital sensor used on technical cameras is much smaller than 4x5, DoF will be much deeper when shooting at the same aperture and FoV.

 

[rga]

Are you thinking about reverse tilt?

 

[ibear88]

Hi,
I get it that landscape photographers may prefer deep depth of field. I like it too. I think my question is more one about the capacity for the digital sensor and technical camera to do short depth of field.

I'm not that knowledgable about the physics of optics but I will take your word that a small sensor will have a deeper depth of field compared to a piece of 4x5 film. Does this attribute of the small sensor make it ineffective to use for the purpose of short depth of field compositions when coupled with a tech camera? Like, can you get a Leica M composition of short depth of field and soft background with a tech camera and digital back combo?

In 4x5, I have used reverse tilt and I have used heavy swing to induce short depth of field. Is that possible with a tech camera and a digital sensor? I've read so much about the limitations of shift with technical cameras, I wonder if those kind of limitations preclude the use of a reverse tilt or swings to effectively induce short depth of field (and smooth bokeh) in the digital and tech camera world?

If anybody has a link to short depth of field images made with a tech camera and digital back, I would be interested.

Thanks for all the comments so far.

Jeff

 

[Jorgen Udvang]

Try the DoF calculator:

https://www.cambridgeincolour.com/tutorials/dof-calculator.htm

As for Leica M, you have access to some very large aperture lenses. If those are sufficient to produce the shallow DoF that you require, only you can decide... and your wallet. A Noct is far more expensive than most large format lenses.

 

[dougpeterson]

For shallow depth of field shots with a medium format sensor I don’t think a tech cam platform is the most common approach. I would suggest alternative lenses on the XF, such as:

https://digitaltransitions.com/fast-portrait-lens-phase-one/

 

[ibear88]

Thanks for the link to the Cambridge calculator. That helps. The calculator clarifies the correlation, of the size of the sensor or film plane, with depth of field.

One tech camera, including shifts, that could do both high resolution and great bokeh would be nice. Perhaps, not practical. Sometime I should rent one along with a long lens and see how I like the results. I also see that Alpa has an adapter to the M lenses, although it requires an electronic shutter and it becomes a quite pricey kit.

 

[dougpeterson]

One tech camera, including shifts, that could do both high resolution and great bokeh would be nice. Perhaps, not practical. Sometime I should rent one.

We have an office in NYC and LA and you'd be welcome to use the tech camera and back equipment we have on-hand to test this workflow. No charge if you're doing so at the shop or nearby, and if it's looking useful you could rent it to use it in longer/more-extended testing.

 

[Ed Hurst]

There is a long, precise answer. But the practical answer is this: depth of field is a function of focal length and aperture. Larger formats involve a longer lens for the same angle of view, so less depth of field. But shooting a digi back on a technical camera involves shooting a format no larger than using the same back on an SLR. So no different depth of field.

So no advantage there, unless you use movements to create the effect you want.

 

[Alan]

I also see that Alpa has an adapter to the M lenses, although it requires an electronic shutter and it becomes a quite pricey kit.

If you have an electronic (IQ3100) or focal plane (Alpa FPS, Fuji GFX) shutter, you could use fast MF SLR lenses (Pentax 67 105/2.4, etc).

 

[pandes]

subscribed, this seems like a very interesting thread

 

[ibear88]

Experimenting with the Cambridge calculator - it looks like one can get to narrow depth of field if using say a lens longer than say 110mm.

I see that Alpa offers a mount for M lenses, although it requires an electronic shutter (or an focal plane shutter alternative). For any scene with movement to it, the electronic shutter sounds like it can introduce distortion. But, the ability to for rise/fall and shift within the image circle is attractive, if not essential.

It would be interesting, to me, to test drive the two alternatives. Perhaps, as Doug offers, when I am in LA sometime.

Jeff