tools for zone focusing

[barnninny]

As my vision get worse with age, I've been mulling ways I can get sharp focus that don't depend on the sharpness of my own eyes. Autofocus is an obvious candidate, but just as obviously isn't an option in the LF world, or even much of an option in MF. (I don't know of anything bigger than 6x4.5cm that has autofocus. Am I overlooking something?)

A more traditional -- not to mention, cheaper -- approach would, of course, be zone focus. Which brings me to my question. What tools are there for getting accurate distance measurements?

A tape measure works over short distances, of course, and even over medium distances, depending on how big the tape measure is and whether or not you can get to the subject. My next thought was one of those rangefinders like golfers and shooters use. After looking into them a bit, though, I've been pretty disappointed with their precision. Some of the high-end models ($400+) have [claimed] precision almost down to the inch, but the rest usually don't claim anything more accurate that +/-3 feet.

That would be okay if you're working with sufficient DOF, but that's pretty limiting. What have you guys used to get accurate subject distances? Are there devices like this that are designed for photography? (Googling any combination of "rangefinder" and any photography term produces RF cameras, of course.)

[Jac@stafford.net]

I doubt that your eyes are worse than mine - uncorrectable to 20/20. I cope by using two good loupes, a 4X and 8X. Anything more powerful than 8X is worse for me on my particular ground glasses. So, try a couple different magnifications.

Also look into Aerial Focusing right here on this site at: http://www.largeformatphotography.info/forum/showthread.php?45251-aerial-focusing

Separate, optical rangefinders intended for cameras exist, but are usually old and dark or broken. Regardless, you would have to mark the rail(s) on a large format camera to translate the rangefinder to the camera, and for that you need to focus on the glass to make the marks the first time. See the two suggestions above.

Hyperfocal techniques do not make it for LF, at least for me. If you use movements, it's almost impossible.

You might consider using a rangefinder LF (largely limited to 5x4 max). The Linhof Super Technika, some Graflex, and my Printex use RF focusing.

[Mark Woods]

There's a company, Cinematography Electronics, that make an electronic tape for cinematography applications. Very pricey and very accurate. My assistant made one and used it on features I shot and his worked quite well. He made his (total geek) but you could buy the CEI electronic tape.

[barnninny]

I doubt that your eyes are worse than mine - uncorrectable to 20/20. I cope by using two good loupes, a 4X and 8X. Anything more powerful than 8X is worse for me on my particular ground glasses. So, try a couple different magnifications.

Also look into Aerial Focusing right here on this site at: http://www.largeformatphotography.info/forum/showthread.php?45251-aerial-focusing

Separate, optical rangefinders intended for cameras exist, but are usually old and dark or broken. Regardless, you would have to mark the rail(s) on a large format camera to translate the rangefinder to the camera, and for that you need to focus on the glass to make the marks the first time. See the two suggestions above.

Hyperfocal techniques do not make it for LF, at least for me. If you use movements, it's almost impossible.

You might consider using a rangefinder LF (largely limited to 5x4 max). The Linhof Super Technika, some Graflex, and my Printex use RF focusing.

Thanks for the info, Jac. That thread is really fascinating, in a totally geeked out kind of way. And I've been keeping my eye on the RF Graflexes on the bay, for that very reason; my little Leica IIIf can be extremely easy to focus, even in quite low light.


There's a company, Cinematography Electronics, that make an electronic tape for cinematography applications. Very pricey and very accurate. My assistant made one and used it on features I shot and his worked quite well. He made his (total geek) but you could buy the CEI electronic tape.

Gadzooks! Looks like an incredibly powerful too, Mark, but $7k is a bit more than I was hoping to spend. :)

[Bob Salomon]

"(I don't know of anything bigger than 6x4.5cm that has autofocus. Am I overlooking something?)"
Rollei 6x6 6008 AF. Hasselblad did offer a couple of rudimentary AF lenses in the 60s. Rollei HY6 cameras.

[Mark Woods]

I should've mentioned that you sit down before reading my post. ;-)

[barnninny]

"(I don't know of anything bigger than 6x4.5cm that has autofocus. Am I overlooking something?)"
Rollei 6x6 6008 AF. Hasselblad did offer a couple of rudimentary AF lenses in the 60s. Rollei HY6 cameras.

Thanks, Bob. I had forgotten about the 6008. Replacement battery/charger availability has always scared me away from those.

[barnninny]

I should've mentioned that you sit down before reading my post. ;-)

No kidding. For the amount of time I spend shooting, I could hire an assistant at that price and have them focus for me (then go hold lights, reflectors, keep the riff-raff away, etc.). Let's see the CEI do that!

[Bob Salomon]

Thanks, Bob. I had forgotten about the 6008. Replacement battery/charger availability has always scared me away from those.

The 6008 operates off of a battery that has been available for decades. It might be dedicated to the cameras but they are around, as are the chargers. There is also aa AA option (which I would not rely on). And most modern digital and most analog SLR and smaller cameras use dedicated batteries today anyway. So do a lot of current MF cameras as well. Even the 45 Linhof Aero Technika EL used dedicated batteries if not used on aircraft current.

[barnninny]

The 6008 operates off of a battery that has been available for decades. It might be dedicated to the cameras but they are around, as are the chargers. There is also aa AA option (which I would not rely on).

Really? Everything I've ever heard about the dedicated ones and the chargers is that they're rare as hen's teeth.

[Bob Salomon]

Really? Everything I've ever heard about the dedicated ones and the chargers is that they're rare as hen's teeth.

Depends on where you look and who you ask. They are easily obtained even now. Easier a few years ago.

[gliderbee]

You might try one of these laser distance meters architects use (a.o.). I have one made by Bosch that works up to 50 meters, accurate to the centimeter.

Stefan.

[Bob Salomon]

You might try one of these laser distance meters architects use (a.o.). I have one made by Bosch that works up to 50 meters, accurate to the centimeter.

Stefan.

But once you know the distance what is he supposed to do? To zone focus he needs footage scales on his camera. Very few view cameras have them. A cammed Master Technika does but only for the lenses cammed. And then there is no DOF scale on the focusing scale on the camera like there is on medium format and smaller cameras.

[gliderbee]

But once you know the distance what is he supposed to do? To zone focus he needs footage scales on his camera. Very few view cameras have them. A cammed Master Technika does but only for the lenses cammed. And then there is no DOF scale on the focusing scale on the camera like there is on medium format and smaller cameras.

He could make a ruler to put on the camera with markers for e.g. infinity, 50m, 25m, 12m, ... A different ruler for each lens of course, each to be calibrated once. It's a lot of work, I agree. I for one would keep working with a loop for as long as I can.

Another tool that might be useful is a laser pointer: it gives a very clear point on the subject to focus on.

Stefan

[Bob Salomon]

He could make a ruler to put on the camera with markers for e.g. infinity, 50m, 25m, 12m, ... A different ruler for each lens of course, each to be calibrated once. It's a lot of work, I agree. I for one would keep working with a loop for as long as I can.

Another tool that might be useful is a laser pointer: it gives a very clear point on the subject to focus on.

Stefan

Be a lot easier to get a brighter gg and Fresnel and a good adjustable loupe. He would need these anyway to make calibrated focusing scales.

[Bob Salomon]

....You might consider using a rangefinder LF (largely limited to 5x4 max). The Linhof Super Technika, some Graflex, and my Printex use RF focusing.

Also the Wista RF. And the Super Technika was replaced by the Master Technika in 1972. But the Super technika 57 was also a rangefinder camera with coupled lenses.

[ic-racer]

Have you tried a magnifier loupe on the ground glass?

[Jac@stafford.net]

And the Super Technika was replaced by the Master Technika in 1972.

Yes, I really should update.

[barnninny]

He could make a ruler to put on the camera with markers for e.g. infinity, 50m, 25m, 12m, ... A different ruler for each lens of course, each to be calibrated once.

Something along those lines is what I was thinking, Stefan. Like the handy little scale on the side of my Mamiya C330. I don't have any plans to acquire or use more lenses than my 150, right now. Someday I'd like to get a longer one, though; a 300, probably.

But you guys are probably right about it being more trouble than it's worth. I'm just looking for options.

[barnninny]

Be a lot easier to get a brighter gg and Fresnel and a good adjustable loupe. He would need these anyway to make calibrated focusing scales.

Maybe I'll look into that and see how far it gets me. Not having used a LF camera before this one, I don't really know how to set my expectations for the GG image. Maybe the GG in this particular camera could be substantially improved on.

[barnninny]

Have you tried a magnifier loupe on the ground glass?

Yes.

[Jim Noel]

"That would be okay if you're working with sufficient DOF, but that's pretty limiting. What have you guys used to get accurate subject distances? Are there devices like this that are designed for photography? (Googling any combination of "rangefinder" and any photography term produces RF cameras, of course.)"

Yes there are such things. When rangefinders began to appear on 35 mm cameras, the demand for unmounted ones grew. They were made by many companies. There are still many around which are clean and working well because they generally came in some kind of small case. Put in a search. I wish you success.

[premortho]

If you are focusing past 50 feet, I would use a hunters lazer rangefinder. For focusing closer than fifty feet, one of the old rangefinders for 120 roll film cameras will work very well. The main advantage to the Kalart type rangefinders used on Speed Graphics is that they are coupled to the lens. With a view camera, that is really no advantage as compared to the un-coupled rangefinders mentioned above.

[ataim]

Easy and darn near free. I've never used it, but in concept it looks pretty sound. http://tomchuk.com/misc/rf/

[barnninny]

Easy and darn near free. I've never used it, but in concept it looks pretty sound. http://tomchuk.com/misc/rf/

I dunno how accurate it would be, but it's clever as hell. Thanks, ataim.

[Drew Wiley]

Decent laser distance meters can not be obtained for as low as about $150 from outfits like Bosch, Stabila, or Spectra. These
all share the same Leica mechanism internally. Don't go cheaper, and avoid anything that says Stanley on it like the plague.

[Drew Wiley]

Sorry... misleading typo .... should be, can "now" be obtained for around $150. It wasn't too long ago that a decent meter
cost more like $750, but they're quite affordable now as long as you stick with a reputable brand.

[barnninny]

Thanks, Drew. I'll look those up.

[Drew Bedo]

There is/was a guy in England who did church interiore in LF with hyper-focal techniques and he was legally blind ("Registetred Blind" in England). He pre-figured the hyper-focal parameters for his lens and cut a stick to separate the front and back standards the correct amount. In use, the stick is placed on the bed rail and the front standard racked back till the stick is held firmly between the standards.

With some calculation and trials, one could make a set of focusing jigs for several combinations of focus and f-stop . . .for a selection of lenses.

Would this work for you?

[barnninny]

He sounds like a remarkable man.

Yes, I assume it would work for me, too. At this point, though, my eyes aren't that bad; I'm hoping for a simpler solution.

[Michael Rosenberg]

I suggest trying a green laser - point the laser on the nearest object and focus, then do the same for the furtherest. Measure the change in the bed of the camera, then move the bed to 1/3 or 1/2 of the distance between the two and stop down. I cannot be corrected to better than 20/35 in my right eye, and 20/400 in the left. I am also night blind. I used this technique for many of my cathedral images.

[barnninny]

I suggest trying a green laser - point the laser on the nearest object and focus, then do the same for the furtherest. Measure the change in the bed of the camera, then move the bed to 1/3 or 1/2 of the distance between the two and stop down. I cannot be corrected to better than 20/35 in my right eye, and 20/400 in the left. I am also night blind. I used this technique for many of my cathedral images.

Much thanks for that, Michael. In fact, if we had a "Thanks" button, I'd click it.

[Jerry Bodine]

I suggest trying a green laser - point the laser on the nearest object and focus, then do the same for the furtherest. Measure the change in the bed of the camera, then move the bed to 1/3 or 1/2 of the distance between the two and stop down.

That will work, but the question becomes how much to stop down to obtain adequate depth-of-field. To get the answer to that question, here (http://www.darkroomagic.com/DarkroomMagic/Camera.html) is one way.
Scroll down to "Depth-of-Focus Ruler", read the directions for use, then open the pdf file and copy the scale and gauge. I did this and laminated them for durability. This will work for you, provided your vision permits you to adequately read the scale and gauge. You'll find that the scale is in millimeters; I did not have to print the scale since my Sinar Norma has this scale built in on both front and rear standards.

[David Karp]

. . . the question becomes how much to stop down to obtain adequate depth-of-field . . . .

This works too: www.largeformatphotography.info/fstop.html.

I made a card, laminated it, and always keep it in my backpack. My field camera does not have a mm scale, so I found one on the web, printed it out, laminated it, and stuck it to my camera with double sided carpet tape.

[john reed]

How about this:
Sinar has an exposure wand that will allow you to detect the light intensity at any spot on the film plane. How about mounting a passive autofocus CCD in a similar fashion and using that to determine the focus at any point on the film plane. This would address the focus with swings and tilts which are a major advantage of view cameras.

I'm looking into what would be required to gin up a prototype. I would imagine starting with a metering wand and an appropriate ccd sensor that culminates in a meter which will show the max sharpness for the point of the film plane. It should work on either side of the ground glass since it would be a relative peak. It could also be mounted at the end of a small tube like a loupe.

Anyone interested in contributing ideas along the line. If so, we could start a separate thread so as not to bore the real people silly with a lot of tecky geek stuff.

[barnninny]

Sounds like an interesting idea, but I'd be no help with the techy geek stuff.

[gleaf]

In the lab we use small video cameras to record very fine inspection defect details. One has a small hand held monitor that fits in the hand, battery powered with AC adapter (wall wart). Light levels should be sufficient.

[Jac@stafford.net]

In the lab we use small video cameras to record very fine inspection defect details. One has a small hand held monitor that fits in the hand, battery powered with AC adapter (wall wart). Light levels should be sufficient.

Would it work with aerial focusing?

[john reed]

An electronic loup. An interesting idea. I had something like a meter that would indicate the peak contrast in mind, but this might be a simpler solution. I'll take a look around the local sources and see if I can find one to test. What brand do you use in the lab?