Hyperfocal ? Voigtlander 15mm

[Authentic Southerner]

I have read and read on this topic until I am I think more confused than when I started.

Here is what I know. The Voigtlander 15mm is a great lens, I plan to use it on my Minolta CLE rangefinder. I have the shoe mount accessory viewfinder to assist with framing the ultra-wide shot. I understand that the 15mm lens has a very broad depth of field and that most say...Set it at 2 meters and f4.5 -f5.6 and you will be in focus from about 2 meters/ 6 feet to infinity.

Without a complex understanding of how to calculate the hyperlocal distance I hope to find out if that general assertion is true ? i.e. set at 4.5-5.6, focus to about 2 meters, shoot and don't worry....

Also I notice on the focusing distance portion of the lens that the distance (on the actual lens markings) between 2M and Infinity is about 1/4 of an inch (very close) and I also notice that the distance between 0.3M and 2M is about 2 inches...

I take that to mean that close focusing, between 1 foot and 6 feet is much more critical than distant focusing between 6 feet and infinity ? Is that a fair understanding ??

Also at the base of the lens I see fixed markings .... white dot in center...4.5 -- 16 out to right and left from center dot...these markings are just behind the rotating distance focus ring...

I will take a pic with my phone and attach so it will make more sense...

I don't have the mathematical mind to deal with off the cuff calculations and honestly don't want to invest the brain power to understand the science of the concept, honestly I just want to know what to do as a general rule and how changing focus distance nearer/farther will shift the range of depth of field... If I can get the general concept I think there is enough "slop" in a 15mm that I won't have to worry too much about fine details.. Thanks in advance for input...

 

[photoguy99]

Put the infinity symbol on the distance mark for the aperture you're using. Done.

 

[Authentic Southerner]

thanks... the distance mark for the aperture I am using being the 4.5 / 8 /11 /16 to right of white dot on innermost lens ring ?

from that I conclude that the distance mark for the aperture markings on the left side of the dot will indicate the close focus range and the infinity mark on the right side the distant focus range... thus as set in the photo my range of focus close to far is about <.5 meter to infinity ?

The infinity focus mark set somewhere between f8 and f11...

Obviously this doesn't match with the aperture setting above between 4.5-5.6 but I think I understand what these markings all mean now..

Am I thinking correctly ?

 

[Derrel]

Currently, the lens is focused at about 2.5 feet, and moving the eye over to the right of the white dot, we see the infinity symbol is lined up between f/8 and f/11, so that means that 2.5 feet is the hyperfocal distance for the aperture that lies between f/8 and f/11.

Looking at the ring and estimating the distance marks and their spacing, I would say that if the lens were focused at 4 feet, that would place the infinity symbol right between f/4.5 and f/8, and so that would mean 4 feet is the hyperfocal distance when using an aperture between f/4.5 and f/8.

As to focusing accuracy with a 15mm lens: yes, at closer ranges, focusing is much more-critical than it is at longer distances. If you really want a subject that is pretty close, like under six feet, to be as sharp as possible, then it is best to focus on that distance, or very close to that distance. At longer distances, focusing with a 15mm lens is much less hair-trigger.

 

[Authentic Southerner]

Gotcha ! So (and I hate to confuse matters) what are the markings to the left of the focus dot ? 4.5/8/11/16 for ? What purpose do they serve ? there must be some point or they wouldnt be there ?

 

[Derrel]

The marking to the left of the dot are where the point of acceptable NEAR depth of field is read off. The dot is the actual point of focus. On the right hand side is where the FAR limit of acceptable depth of field is read off.

 

[Derrel]

Here is the DOF scale for a Nikon 80-200mm f/4 zoom lens. Keep in mind, Nikon's focusing ring travel direction is opposite from most of the newer Japanese brands. This sample picture has the focusing set to about 3 meters. The apertures on older Nikon lenses are color-coded.

A depth of field scale of this specific type might help you understand a bit more about how DOF gets "narrower" as the lens is zoomed. See how much narrower the lines are spaced down in the 135mm and 200mm ranges?

 

[Authentic Southerner]

Thanks much for the lesson... facts I never learned during the 80s when I enjoyed film photography... Am happy to have finally at least grasped the concept... the good news is as predicted with the 15mm Voigtlander that focus is not accurately portrayed in the rangefinder viewfinder is essentially irrelevant.. the most important variable being trying to establish the frame and orientation as to the horizon.. and of course the usual shutter/aperture settings...To have learned something every day is to me one of the greatest accomplishments !