Where is infinite focus?

[Helen B]

Mike,

The important thing is that you know what you want, and you know how to get it. Thank goodness that we don't all do things the same way.

Best,
Helen

 

[Helen B]

I have just come across another article on depth of field in landscape photography that may be of interest : http://www.englander-workshops.com/documents/depth.pdf It is mainly for large format, but much is relevant to all landscape photography.

Best,
Helen

 

[ksmattfish]

Depth of field is all about setting the limits of acceptable blur. If you set the lens to the hyperfocal distance the horizon will not be in sharp focus, but it will be out of focus - in fact it will be just on the limit of acceptable blur.

If the horizon is not in sharp enough focus, and that isn't acceptable, then wouldn't that be an example of outside the limit of acceptable sharpness?

You may run into this problem when using someone else's idea of the hyperfocal distance (like the camera/lens manufacturer or a DOF calculator) which is why everyone should do personal testing with their own gear to determine their own settings, and of course each photographer must make their own judgment on what is "acceptable".

For tricky night focusing I shine a laser pointer where I want to focus. It's easy to see when it's in focus or not.

 

[Jeff Canes]

Auto focus works by see the contrast between colors. In a dark setting it may not work well. Matt subjection to use a laser pointer should help with both auto and manual focusing.

 

[Helen B]

"If the horizon is not in sharp enough focus, and that isn't acceptable, then wouldn't that be an example of outside the limit of acceptable sharpness? ;-)"


Yes, there is plenty of scope for word-play with this subject. In practice everyone should decide the relative importance of sharpness in different parts of the image for themselves.

As for the laser pointer, in cinematography we use a laser that is synchronised to the camera shutter - so it is visible in plain view and through the viewfinder, and by the follow-focus system but it does not record on film.

Best,
Helen