The utter joy of manual focus

[Itsallicanafford]

I attended a Christening over the weekend so decided to fish out some of my old gear a run a roll of film through it.

So after I had cured the stuck shutter on my Canon T90 (by firmly banging it on the table, well the Japanese used to call it 'The Tank') and with just the standard 50mm 1.8 I shot a roll of FP4.

What total and utter joy to compose a shot, focus manually and see the image in sharp focus on a large bright uncluttered focusing screen.

For those of you that have never done it, i would highly recommend it...

When i get the result back i will post one up (so they better be in focus!)

[MysteryLemon]

Must admit that I miss the viewfinders on old manual film SLRs. They were so much better than what we get these days, even on very expensive kit.

[Simpo Two]

Stick a digital back on it and Bob's yer uncle.

[marctwo]

Simpo Two said:

Stick a digital back on it and Bob's yer uncle.

I didn't think these existed for 35mm?

[K12beano]

marctwo said:

Simpo Two said:

Stick a digital back on it and Bob's yer uncle.

I didn't think these existed for 35mm?

Probability is you don't have an Uncle Bob either. But - in a universe somewhere - I'm sure someone's gaffer taping a sensor into an analogue body. Camera manufacturers just wouldn't be profitable if they'd solved this one!

Agreed, that sometimes MF is a nice experience, but it's all a compromise on digital!

[Simpo Two]

marctwo said:

Simpo Two said:

Stick a digital back on it and Bob's yer uncle.

I didn't think these existed for 35mm?

I think they were experimented with but never caught on. But the point I meant was that then you could have all the big bright ground glass fresnel split-prism loveliness of a 35mm SLR and 1.8 lens with the convenience of digital

[MysteryLemon]

Simpo Two said:

I think they were experimented with but never caught on. But the point I meant was that then you could have all the big bright ground glass fresnel split-prism loveliness of a 35mm SLR and 1.8 lens with the convenience of digital

I think it was more down to the fact that every body would need a different solution.

I have seen ideas of having "digital film" where the sensor and electronics are all contained within a film roll canister with a very thin strip that goes across the shutter that contains the sensor. Doable i'm sure but again, every camera will be different and require a different solution. Film cameras just aren't designed in any way to take a static piece of media to record on to.

[Simpo Two]

MysteryLemon said:

I have seen ideas of having "digital film" where the sensor and electronics are all contained within a film roll canister with a very thin strip that goes across the shutter that contains the sensor. Doable i'm sure but again, every camera will be different and require a different solution. Film cameras just aren't designed in any way to take a static piece of media to record on to.

Well, they were all designed to take a piece of 35mm film that was static at the time of exposure.

[Itsallicanafford]

Its interesting that Pro full frame digital cameras still have compromised viewfinders. Is there a reason for this? I always sort of assumed that looking through a D4 would be similar to looking through an F5 or F6

[MysteryLemon]

Simpo Two said:

Well, they were all designed to take a piece of 35mm film that was static at the time of exposure.

Static at the time of exposure but then moved immediately afterwards. The position of the frame on the film will be different in every camera body. Unless you come come up with some infinitely positionable sensor that could fit in the place of a paper thin piece of film, then I think you're going to struggle. I suppose you could have an oversized sensor (in width) to compensate for not knowing the position of the frame but then you still have the paper thin design to overcome. Maybe there is technology out there to do it? I dont know.

Edited by MysteryLemon on Monday 20th April 17:23

[Simpo Two]

MysteryLemon said:

Static at the time of exposure but then moved immediately afterwards. The position of the frame on the film will be different in every camera body. Unless you come come up with some infinitely positionable sensor that could fit in the place of a paper thin piece of film, then I think you're going to struggle.

Do you mean position left/right/up/down or backwards/forwards?

I expect it would be bang on the centre line of the lens. If you could get a sensor the same size as a frame of 35mm film (which you can), and place it where the film would normally go (the little underground station symbol on the body) I can't see why it wouldn't record the light the same as the film.

[MysteryLemon]

Simpo Two said:

Do you mean position left/right/up/down or backwards/forwards?

I expect it would be bang on the centre line of the lens. If you could get a sensor the same size as a frame of 35mm film (which you can), and place it where the film would normally go (the little underground station symbol on the body) I can't see why it wouldn't record the light the same as the film.

But thats what I mean, you could position it exactly in the right place but then that position would be different for every body. You would need a specific solution for each body out there as the position would differ from body to body. Just isn't viable i don't think. Probably why we've never seen one. The demand isn't there and the tech is too expensive or doesn't exist yet.

It can be done and has been done but it's always been a modification by someone spending hours designing and hacking a body to fit digital components into it. Hardly an off the shelf solution to make any SLR a DSLR.

[Simpo Two]

Open back, stick sensor on, run wires to electronic gubbins where the film spool would be... I see it as a maker's upgrade not eBay special. But we're 10+ years out on this.

[Super Slo Mo]

It's got to be a case of the sensor being thicker than the film, so the back door would need modifying.

Not only that, and this is more critical, that thickness of the sensor will incorporate an IR Filter, so meaning that the sensor won't be quite in the correct place for the focal plane of the lenses, so non of your lenses will focus properly, especially not wide open. And yes, a few hundredths of a millimetre is all it takes. To get around this will require some very precise machining.

[Simpo Two]

I'm sure Nikon, Pentax, Canon, Olympus and Minolta could have managed it. But history took a different route, perhaps because of all the extra controls and room needed.

As for needing 'a few hundredths of a millimetre' to get sharp focus, is a wobbly bit of celluloid strung between two rollers that precise? Evidently so.

[Bacardi]

Simpo Two said:

As for needing 'a few hundredths of a millimetre' to get sharp focus, is a wobbly bit of celluloid strung between two rollers that precise? Evidently so.

Not really. Lenses have a tolerance called 'depth of focus': http://en.wikipedia.org/wiki/Depth_of_focus

There was a Contax which had a vacuum to suck the wobbly bit of celluloid flat for optimum results.

IIRC there was also a gizmo that fitted the film canister chamber and had a bit with the sensor stretching out of the the film plane aperture, but this was in the ealy days and never took off.

The only manufacturer I can think of to make a digital back for a 35mm film camera was Leica, with their DMR. So you can use your R9 for film or digital. The sensor doesn't have an IR filter so punches above its 10mp resolution and focusing manual Leica lenses makes modern Canon/Nikon etc feel like Fisher Price

[Itsallicanafford]

This guy had the idea

http://petapixel.com/2013/08/16/convert-your-old-f...

Don't think it caught on...

[RobDickinson]

Itsallicanafford said:

Its interesting that Pro full frame digital cameras still have compromised viewfinders. Is there a reason for this? I always sort of assumed that looking through a D4 would be similar to looking through an F5 or F6

Because manual focus is only used y a fraction of people and its on average better to have a bright viewfinder for slower lenses and all the digital/autofocus information than a clear fast focus screen thats useful to about 2% of shooters.

Pro's mostly dont manual focus. Left that behind in the 80's.

And for when you do you can always use live view or a focus peek system on modern evil cameras.

[tog]

Simpo Two said:

Open back, stick sensor on, run wires to electronic gubbins where the film spool would be... I see it as a maker's upgrade not eBay special. But we're 10+ years out on this.

Nearly 25 years out in fact, although the electronic gubbins were in a large external box not just the space where the film spool would be.

http://camera-wiki.org/wiki/Kodak_DCS_100

[Super Slo Mo]

Simpo Two said:

I'm sure Nikon, Pentax, Canon, Olympus and Minolta could have managed it. But history took a different route, perhaps because of all the extra controls and room needed.

As for needing 'a few hundredths of a millimetre' to get sharp focus, is a wobbly bit of celluloid strung between two rollers that precise? Evidently so.

I guess it is. Without opening up a film back, which would necessitate digging one out from wherever they are stashed, I seem to recall there was a spring loaded 'plate' of some kind that gently pressed the film flat and tight.

As the other poster mentioned, Depth of Focus is the factor. It's just like Depth of Field, except at the back of the lens, and also varies with iris/aperture opening, so it's non-existent at large apertures.

On Broadcast spec lenses, there is an adjustable flange at the back of the lens that allows the operator to precisely adjust the focal point of the lens so it hits the 'film' plane exactly. The amount of movement is more or less imperceptible to the naked eye.
I think this is to allow for tiny differences in manufacturing tolerances, or perhaps that level of precision isn't so critical on larger chips like DSLR cameras.