IR Jim Loc: St. Louis

I was thinking how cool it would be to a DOF priority setting on a DSLR.
It would work on a single focus point and you could dial in how much DOF you desire behind the focus point. I'm a big fan of the metric system but it would also support imperial measurements. The camera would detect what lens you have and limit the DOF you could select. Shutter speed, aperture, and optional ISO would be automatic. The only major new hardware the camera would need to make it really efficient would be a new rangefinder system, perhaps and Eye-safe Laser Rangefinder (ELRF). I imagine it would be more accurate than current rangefinders that rely on trigonometric parallax, especially on shots with really shallow DOFs at lower F-stops.

Would any of you use a setting like this?

OddJobber Loc: Portland, OR

You lost me at trigonometric parallax, but I like thinking outside the box.

IR Jim Loc: St. Louis

Perhaps I should have said triangulation instead.

HEART Loc: God's Country - COLORADO

Interesting!

IR Jim Loc: St. Louis

I should note that I did not mean to imply that modern DSLRs have trig rangefinders. They have been used on cameras before and I imagine it would be cheaper, easier to integrate, and much lighter to produce than an ELRF.

kruchoski Loc: Albuquerque, NM

This is a rich topic (IMHO) because DOF is so important for turning 'ho-hum' photos into pretty decent photos. (There are a lot of those so-so pics posted here, which is another topic unto itself. Lest you start thinking I'm a snob for saying so, I'll confess I take lots of so-so pics, but at least I know they are. And 'bad' DOF is rarely the most egregious of my sins.)

Just last night I was researching the advances in using mobile devices (smartphones, tablets, iPads) to control DSLRs and add 'live view' capabilities to older (or lower-end) models. I'll be testing an Android app called (oh-so-imaginatively) DSLR Controller [ http://www.dslrcontroller.com -- imagine that! ] as soon as I get the special "OTG" USB cable or adapter to connect my Samsung Tab 3 to my Canon T2i and Xsi cameras.

I'm guessing that DSLR Controller could easily incorporate such a feature or mode. In fact, I might send a link to this topic to the good folks who are developing this app. It's a patentable concept.

(Primer on patentability: You must enumerate your claims, then describe how to make & use a new, useful, and non-obvious 'invention.')

Would I use it as a primary shooting mode? No. But if it were programmed as a 'hard stop' feature -- i.e., "never allow a shutter-aperture-ISO combination that violates the DOF constraints selected" -- I definitely would use it a lot.

Incidentally, the new patent law (since March 2013) is first-to-file, so if you can meet the requirements above, get thee to the USPTO mucho pronto.

IR Jim Loc: St. Louis

It is only at the idea stage at the moment. Thought of it this morning sitting on the deck drinking coffee and watching the sunrise. With as much R&D that goes on at camera manufacturers and the number of photographers in the world, I sincerely doubt I'm the first one to think this up. As much fun as it would be to create engineering drawings and build a prototype I don't have the time or place to do it. I'm looking to buy a house now and when I get one (with a workshop) my first project will be grinding my own telescope mirrors. I really hope it would become a setting one day, I could put away my DOF cheat sheets once and for all.

kruchoski Loc: Albuquerque, NM

Disclaimer: I'm not a patent attorney.

Every patent application is a crapshoot. Yes, it's obvious that lots of brilliant people all around the world are coming up with virtually the same new inventions simultaneously!! And given the time lag for patents to be granted & published after the application is first submitted, not even the big guys (for example, Samsung) can know who'll be first & who'll infringe on another's patent (or how).

More importantly, one needn't "reduce to practice" (i.e., build an operable prototype) in order to get a patent.

Your point is well taken, however. Most of us have other, more important tasks at hand.

My important task this afternoon was to download, install, & test that DSLR Controller app. So far, so good. Some shortcomings (on my Xsi), but some really neat features that I don't understand yet. It's quite promising.

Peekayoh Loc: UK

Automatic? I don't like the sound of that.

There's no need for new hardware, the camera already knows the focus distance, the focal length and the aperture so it would be quite easy for the camera to a calculate and display the DOF; it would be easy to automate the process. I think Canon had/has a system where you can choose a near point and a far point and the camera would set an appropriate aperture.

Not the Automatic version but a DOF display would be handy but not essential. If a reminder is needed, I tell youngsters at the club to get DOF and Hyperfocal Calculator on their smartphone.

IR Jim Loc: St. Louis

I should clear this up, I meant an optional setting for auto ISO. I suppose I shouldn't have mention ISO since you can select it's function in current Aperture and Shutter Speed priorities.



I am quite certain the camera only knows if the subject is in focus, it does not know the actual distance (which it would need to know in order to calculate the DOF you would want behind the focus point).

IR Jim Loc: St. Louis

I'm sure there would only be certain uses for it and you made me think of another feature to add, Lowest / Highest Shutter Speed Cap. This shot for example I could have selected DOF Priority and set it to about 2 feet to have this bird in focus. The actual DOF in this shot was about 2.5 inches but the bird would not wait for me to look it up on a DOF calculator and drag a measuring tape out to the birdfeeder. :lol:

Cardinal (I had focued on the squirrel guard)

Peekayoh Loc: UK

Well yes, that's a given.

All I'm saying is that I'd rather just have the distance displayed in the viewfinder rather than fiddling about dialling in a required amount.

By the time you dialled in the required DOF distance, the moment would be gone.

IR Jim Loc: St. Louis

As I think about it more the only function that would have to be automatic would be aperture. I understand how many of you would not like a fully automatic feature. I wouldn't mind unless I was trying to freeze motion as in the picture above. It would be better if AUTO Shutter Speed and AUTO ISO could be enabled/disabled independently. Optional constraints on min/max shutter speed and ISO would also be handy.
One situation where I could have used a DOF setting was when I was photographing my baby crawl on the floor, I had fast lens and wanted a good amount of bokeh. Continuous Autofocus would keep his eyes sharp but parts of his head would blur due to him moving to and fro thus affecting the DOF. I imagine when he grows up and plays sports I could set the DOF to 1-2 feet and keep him sharp while getting good bokeh.

IR Jim Loc: St. Louis

With such a setting I could have had it set to say 1 foot prior to walking outside to photograph the birdfeeder. The bird would have been in focus.

Peekayoh Loc: UK

Yes but that presupposes you know what setting you are going to need.

Look, I'm not saying having an automatic DOF setting won't work in theory, I just question the value. A visual display would be more helpful but that's just my opinion.