[BigMackCam]

I just received a beautiful "new in box" Canon EOS 5 35mm SLR, and have a couple of inexpensive prime lenses arriving in the next couple of days, which I'm looking forward to trying out. Just tonight, though, I got to thinking... I have fine tuned the AF in my Pentax DSLRs for each of the lenses I own, but I wondered whether this facility / practice existed on AF film SLRs too, or if it's a product of the digital era instead? I'd have thought that the same problems with tolerances in camera manufacture must be present in film bodies, and in fact I'd have thought it is more difficult to guarantee a consistent distance from the lens to the film plane due to potential movement of the film medium. So my questions are (1) does this same potential issue exist using a film SLR with AF lenses, (2) if so, how much of a problem was this for photographers in the past (did it result in a greater number of inaccurately-focused shallow-depth-of-field shots), and (3) did any film SLRs offer AF fine adjustment for lenses? This doesn't bother me - I bought the camera to have some fun with film, and I'm not too concerned if I get variable results. But I'm interested to know

[Unregistered User 8]

Great question BMC. I don't know either, so I will be watching this thread with much interest.

[CarlJF]

AFAIK, micro focus adjustment didn't exist in the film days. You had to bring the camera and lens in a shop if you thought they need adjustments. For what I remember of these days, the rule of thumb was to not trust the AF and go MF for anything requiring precise focusing. Which wasn't really difficult since the VF was made with MF in mind...

So, for your questions:

1) Yes
2) You get to know your equipment and know what was AF great and what wasn't. For most people,the easiest solution to deal with this was simply to switch to MF when you were in a situation you knew you couldn't trust the AF.
3) AFAIK, no. See above.

[MadMathMind]

I have the MZ-S. It's certainly the most advanced film SLR Pentax ever made, perhaps one of the most advanced ever made. (Although others likely had better AF systems or whatnot.) The MZ-S has no fine focus adjustment.

The LCD of film SLRs was a late addition and very limited in what you can see. Furthermore, how you would even *do* the adjustment is a major question. You'd have to shoot with a variety of settings, wasting a roll of film. Then you'd have to develop it. If you weren't capable of doing your own, that would mean waiting a week or more. Then you'd need to blow them up to see the detail. And then you'd have to remember which photo was which setting.

Unless your AF is *way* off, you're not going to notice much at 5x7 or 4x6. Perhaps even 8x10--printing of the time wasn't that good. Given the little return and the HUGE hassle of it all, it wasn't a feature anyone was clamoring for, more likely than not.

[Adam]

Since phase detect autofocus has been around since the film era, so have adjustments (i.e. at repair shops)- but I don't think users could make those adjusents themselves until DSLRs came about.

[One3rdEV]

Ahhh, the ole film days. A much simpler time. At least as far as pre-AF is concerned. A time with well developed off-the-film-plane metering & true TTL flash metering. A time when you could buy a lens and simply just mount it on your camera. A time when you could expect that the camera and the lens both shipped from the factory set within a notably tight optical tolerance. When manufacturers did not ship product having a wide specification range, and gross lack of attention or effort to seek nominal - hiding under the guise that electronics make the product easy to tune; and that somewhere, somehow, somebody is going to do the end of production line tuning that they no longer feel responsible for.

Mind you I love my Pentax digital equipment. But I am rather surprised by the trend of where the manufacturing aspect of the industry is headed, considering where it once was.

[stevebrot]

Since phase detect autofocus has been around since the film era, so have adjustments (i.e. at repair shops)- but I don't think users could make those adjusents themselves until DSLRs came about.

This is definitely true. Pity the means to make the adjustments is not exposed to the user.

...You'd have to shoot with a variety of settings, wasting a roll of film. Then you'd have to develop it. If you weren't capable of doing your own, that would mean waiting a week or more. Then you'd need to blow them up to see the detail. And then you'd have to remember which photo was which setting.

It is easy enough to assess focus accuracy with most film cameras by simply placing a groundglass plate across the film gate and viewing the image with a magnifying loupe. I have an Olympus split-image focus screen co-opted for that purpose for adjusting rangefinder calibration.

BTW...Your EOS 5 has eye-controlled focus point selection...very cool feature


Steve

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Last edited by stevebrot; 04-01-2016 at 10:04 PM.

[stevebrot]

I wondered whether this facility / practice existed on AF film SLRs too, or if it's a product of the digital era instead?

It is a product of the fairly recent digital era. It has only been in the last few years that user tweaking of PDAF calibration was a dSLR feature.


Steve

[pentaxus]

With a digital camera you take the picture and then have the ability to evaluate it by zooming in on the image right after you take the picture. With film you would have to take pictures, then look at the negatives under a magnifier or have expensive test equipment. Letting you adjust focus would not be practical.

[BigMackCam]

Thanks for the replies, all. Interesting stuff. It kind of suggests that the average hobbyist photographer during the AF film era probably was less fixated on absolute AF accuracy than we've become with our DSLRs? I wonder too how the AF algorithms compare to what we now take for granted with current DSLR technology... The limited experience I have with film has been with MF lenses. I'm interested to see how well this EOS 5 handles its AF duties

BTW...Your EOS 5 has eye-controlled focus point selection...very cool feature

Yeah, I've been reading about that. It only works with the camera held horizontally, but it sounds like a clever feature...

[wombat2go]

https://www.graflex.org/articles/auto-focus.html

A day late?

[zapp]

You basically should understand now why a flat digital sensor reveals any misalignemnt of classic cameras. Alignment between lens and focusing screen or distance meter was always a tricky thing. One could always blame film unflatness when problems occured, so pressure plates were used to keep film flat. I think Alpa is the only manufacturer who allow manual shimming/adjustment by the user fro all lenses and film/digital backs.

[stevebrot]

Letting you adjust focus would not be practical.

Probably not, though you don't even need to have film in the camera to evaluate and adjust the focus system on most film cameras.


Steve

[stevebrot]

https://www.graflex.org/articles/auto-focus.html

A day late?

This is good for a laugh, but such a system would work and it occurred to me that all dSLRs having live view might have the means, on-board, to auto-calibrate the PDAF system using the CDAF system using a variation of the popular DotTune protocol. I suppose I should research to see if the idea has been patented. Oops! Spilled the beans by mentioning it here!


Steve

[CarlJF]

This is good for a laugh, but such a system would work and it occurred to me that all dSLRs having live view might have the means, on-board, to auto-calibrate the PDAF system using the CDAF system using a variation of the popular DotTune protocol. I suppose I should research to see if the idea has been patented. Oops! Spilled the beans by mentioning it here!


Steve

The newest Nikon (D500 and D5) have this auto adjust feature.