DOF scale

How come that almost everyone say that the older lens have a DOF scale and newer lenses don't?

When you actually go and compare you will find that almost all the prime lenses (new or old) have a DOF scale and almost non of the zooms. It's quite logical since with prime lenses it's a fixed value but with zoom it changes depending the focal length.

Has it something to do with it that people use prime lenses more in the old days and now zoom are more popular?

Old zooms often have DOF scales, but usually only the trombone type.

Trombone zooms don't seem fashionable these days.

Far better to use DoF tables, there are some good iPhone apps.

Yes only some lenses from the Pentax A series have the scale on the "zoom" tube but older lenses like the M or K series don't have it.
Don't know how it is with other brands?

Sorry I don't understand it really, do you mean it's not on the newer lenses because there is an iPhone app?

Actually you brought me on a good idea, why can't they display the DOF scale on the back of the LCD screen? Lenses these day give away the focus distance they are so it should be possible.

No, I've always used depth of field tables.

Good idea about displaying it on the screen - patent that idea now.

I've truly never used a DOF table, if I want to know the DOF I simply use the optical preview. I'm probably just too lazy too look them up I think

I use "iDoF Calc" off the App Store - it includes hyperfocal distance as well (which is handy).

I'm not 100% sure that the Pentax K interface 'knows' the distance. I have a feeling that there is no suitable info (and even if there was it would probably be very granular).

Matt

Matt look at your EXIF data with the lenses with a digital info contact you've some form of focus distance.
Also Dimitrov talks about it. link
The F 50/1.7 at most 16 different distance settings according to him.
Good enough I think show the relative interesting part of the chart.

But going back on topic, which zoom lenses do have a DOF besides the few lenses from the Pentax A series?

Lots of independent makers' lenses do - far too many to really catalogue.

Thank you John, I thought there where only a few that did it.

I'm using 'simple DOF' with cinematography and film formats up to 10x8, quite comprehensive.