MF AF

[Dick Roadnight]

I bought an MF back to use it on a view camera, but for a grand or so more than the back price, I got a complete MFDSLR with an auto-focus zoom, which I thought was good value for money.

Today I was photographing ballerinas in supposedly static poses (if you can stand still with one leg horizontal) ...the photographs are to accompany an application for an audition for admission to a ballet school.

When I was setting up the studio (photographing a light grey reflector on a dark grey chair) the autofocus worked.

When I got the lighting set right and started photographing the ballerina, the autofocus would not lock on and allow me to take a picture, so I gave it up and focussed manually.

I was using 4 1500 ws Elinchromes (at between 1/4 and 1/16 power) with all the modelling lights full on, under a low white ceiling. (A gallery at the rear of a dance studio/hall, with a window.)

Was I doing anything wrong?

Do you have to get your models to wear contrasty checks to enable you to auto-focus?

Will the H4D-60 be any better? (I was not having to focus and re-compose, as I was photographing one ballerina).

[gdwhalen]

I am probably in the minority and this statement does not address your AF issue but when I shoot people I don't use AF.  I just don't find it reliable in the sense of what I want to be the focus point.  I've tried to autofocus w/people but just can't get the results I want.

[Dick Roadnight]

I am probably in the minority and this statement does not address your AF issue but when I shoot people I don't use AF.  I just don't find it reliable in the sense of what I want to be the focus point.  I've tried to autofocus w/people but just can't get the results I want.

When we had split-image rangefinders, I focussed on the ears, so that the hair was sharp, and the  face was slight soft-focussed ...has anyone invented an AF system that will do that?

Can I have a split-image focussing screen for my   HD3/4?

[Dick Roadnight]

There are many ways... I could have used the built-in fill flash to trigger the studio flash system (no problem if no one else is using flash), but it now occurs to me that I could have used the infa-red beam on my SCA unit of my Metz TTL flash for the Autofocus... this would add another half kilo to a 3 or 4 kilo camera/lens combo! ...presumably the beam needs the flash battery, and I cannot use it without?

For "big room" work I am thinking that I would use the 4 big Metzs for the main subject, and the 4 1,500 ws Elinchromes for the background (which might be a 10 * 30m theatre stage), and my 4 35 year old Bowens flashes for any corner that needed a little more light.

[Jonathan Wienke]

A laser pointer aimed at the intended autofocus target (as long as that isn't somebody's eye) pretty much guarantees correct focus lock, assuming that AF is calibrated properly in the first place. The only drawback is that you need to turn off the laser before shutter release.

[tho_mas]

Can I have a split-image focussing screen for my HD3/4?

e.g. from Bill Maxwell or Brightscreen

[AlexM]

I heard H4D will have an improved AF assist light.
Currently in lower light environments I ask an assistant to point a flash light at a model's face for a couple of seconds for focusing.
MFAF leaves a lot to be desired. Sometimes it works in absolute darkness sometimes it won't lock in normal light settings.

[Dick Roadnight]

A laser pointer aimed at the intended autofocus target (as long as that isn't somebody's eye) pretty much guarantees correct focus lock, assuming that AF is calibrated properly in the first place. The only drawback is that you need to turn off the laser before shutter release.

Thanks...

Custom option 16  (AF assist light) was set to "external". which I had used for my Metz flashes, an I should have set it to "camera" to use the AF assist light on the camera for use with a studio flash system, or in low light conditions.

It seems to work OK when there is contrasty detail to focus on, but I wonder if it would work on the fine-mesh leotards?

With bright modelling lights on, I would have thought that AF should have worked without the AF assist light.

I need to create custom profiles for studio flash, or Metz, etc.

[eronald]

When we had split-image rangefinders, I focussed on the ears, so that the hair was sharp, and the  face was slight soft-focussed ...has anyone invented an AF system that will do that?

Yes, they have invented a system to give sharp ears and hair and blurred eyes. It used to come as standard on most digital SLRs and was called "Backfocus".

On recent models eg. Hasselblad it seems this feature has sadly been deprecated, however one can still restore on the more advanced models  with the help of a menu item called "Focus micro-adjustment"

Glad that at least one forum member has realistic expectations of what a digital camera can be expected to do.

Edmund