authorizeduser Loc: Monroe, Michigan

What determines if the focus indicator light functions? I want to try an old lens from film days. Been told I can set it up in non cpu and have metering work but will focus indicator work?

Lens is Tokina 500mm F8 mirror lens.

RWR Loc: La Mesa, CA

Check your user's manual under "Compatible Lenses." I'm pretty sure your focus indicator will only work with lenses f/5.6 or faster, so you'll have to use the focusing screen.

BHC Loc: Strawberry Valley, JF, USA

What camera. Some will indicate focus at f/8. It's usually the same as your AF limit.

jerryc41 Loc: Catskill Mts of NY

A quick test with the lens should give you the answer. I would think that the camera analyzes the image on the sensor to determine focus.

authorizeduser Loc: Monroe, Michigan

Reading the Nikon D300 users manual answered my question. For the focus indicator to work the lens must have a speed of 5.6 or greater. Appears 8 is NOT going to work.

jerryc41 Loc: Catskill Mts of NY

Good to know.

agillot

on a D300 , i use long lenses / T mount , manual focus , no focus aid there , will not work .but A priority on exposure will work .

amfoto1 Loc: San Jose, Calif. USA

I do not use Nikon or D300... I use Canon, but it might be the same.

When using an adapted, manual focus lens with my Canon's, in order for the Focus Confirmation to work I have to remember to first switch the camera to One Shot (I think Nikon calls it Single Servo AF or something like that). Focus Confirmation can't and doesn't function at all in AI Servo (Nikon Continuous Servo AF?).

In order to set my Canon to the correct focus mode for Focus Confirmation, it's necessary to have one of my modern AF lenses mounted on the camera. So, in other words, if I want Focus Confirmation to work with those adapted vintage lenses, I have to first set the camera up with a different lens installed... I also have to set up the focus pattern (such as Single Point or Multi Point) and select the AF point I want to use, while the modern AF lens is still on the camera. Then when I switch to the adapted, vintage lens, Focus Confirmation will work and the focus pattern/AF point selection I set up earlier will work with it, too.

However, the adapter used on the vintage lens needs to be "chipped"... Those adapters are available with and without those electronic contacts. On Canon, only the ones with the contacts will enable Focus Confirmation. They cost a little more, but I've found them worth it.

On my Canon there really is no f-stop limit with adapted, vintage lenses... But, AF and Focus Confirmation on most Canon may stumble a little at f5.6, will start to slow down and falter more noticeably at f8 or so, then typically fail with f11 and smaller apertures. To a large extent, the contrast of the subject and lighting conditions influence this, too. If the subject is well lit with lots of contrast and detail for the AF to lock onto, Focus Confirmation will work better at smaller apertures than if lighting is flat and the subject has little contrast and detail.

Note: adapted vintage lenses do not remain wide open until the instant of exposure, the way a modern lens does (presumably the same on Nikon as on Canon... and the way those vintage lenses might have done when used on the cameras for which they were originally designed).... So the max aperture of the lens isn't maintained. The lens actually stops down whenever any smaller aperture is selected, so whatever is set will dictate whether or not Focus Confirmation is slowed or if it will even work at all. (BTW, the optical viewfinder will dim down, too... when smaller apertures are set on the adapted, vintage lens. Live View with Exposure Simulation enabled can help the photographer see to compose and focus, but it's difficult to use with anything other than a completely stationary subject.)

This was shot using a vintage, adapted, manual focus macro lens on one of my Canon....



This a Tamron lens with interchangeable Adaptall2 lens mounts....not really an adapter, per se... but a completely interchangeable bayonet mount that allows the lens to be used on virtually any 35mm SLR system.

But it works the same way as an adapter, is "chipped" in the same manner. And - thanks to shooting a highly detailed/contrasty subject in strong, full sun - in this case Focus Confirmation did work in spite of f11 being used (even though the particular camera model's AF is only rated to f5.6)... However, I still had to take about 75 shots just to get a few good ones, it was very difficult to maintain focus on the quick moving subject, plus a light breeze moving the flowers around, and especially with the relatively shallow depth of field of a macro close to 1:1 magnification. I had to trip the shutter very quickly, as soon as I got Focus Confirmation (even when in focus, a lot of the shots were no good for other reasons: poor composition, subject facing the wrong way or partly hidden, etc.)