EOS 1000FN AF

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chris-red

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Just checking something I here I bought a EOS 1000FN to start doing a bit of film shooting and the AF is Terrible in anything but bright light! You have literally no chance of it focusing on somebodies face inside or in low light, with the ****** weather I haven't had much chance to use it outside in daylight. It'l focus on say a lamp or on an on TV.

Just checking this is a limitation of the technology of the time not a problem with the camera. The lens is a Nifty Fifty with works fine (aside from a noise AF motor) on my modern bodies. The 35-80 USM lens that came with the camera is also the same.
 
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I own an EOS 33. Not the same camera, I know, but similar. With a 50mm 1.8 on, it does hunt a fair bit in the dark, more so than when it's attatched to my DSLR.

Someone correct me if I'm wrong, but I think it is partially to do with the lens too. My canon 50mm 1.8 struggles to focus in the dark more than my Sigma 30mm 1.4 (both on a DSLR in the same scenario).
 
I think that would simply be because the 1.4 is letting in almost twice as much light, it's interesting to see how AF has progressed! It never occurred to be it would be something that has got much better!
 
chris-red said:
I think that would simply be because the 1.4 is letting in almost twice as much light, it's interesting to see how AF has progressed! It never occurred to be it would be something that has got much better!
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It wasn't letting in twice as much light; as I stated, both at the same aperture / shutter speed / ISO - the sigma is much quicker to focus (well, it's actually able to focus in very dim light)

But yeah, even on my very modest DSLR, the focusing is better, certainly in the dark at least. I'm interested to try an EOS 3 / 1V and see the difference in them and modern DSLR's seeing as the focus system was the same until the 5D3 came out.
 
Ash. said:
It wasn't letting in twice as much light; as I stated, both at the same aperture / shutter speed / ISO - the sigma is much quicker to focus (well, it's actually able to focus in very dim light)
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It is letting in twice as much light - the lens will meter and autofocus wide open, so the maximum aperture is what is important. One small caveat is that not all bodies can use apertures wider than a given amount for extra metering efficiency or autofocus accuracy. From what I remember, Pentax uses an effective aperture of about f2 for focussing and metering irrespective of whether the lens is faster than this. Naturally, this is not the same as the imaging aperture, so you still get the benefit of the faster glass there.
 
Ash. said:
It wasn't letting in twice as much light; as I stated, both at the same aperture / shutter speed / ISO - the sigma is much quicker to focus (well, it's actually able to focus in very dim light)

But yeah, even on my very modest DSLR, the focusing is better, certainly in the dark at least. I'm interested to try an EOS 3 / 1V and see the difference in them and modern DSLR's seeing as the focus system was the same until the 5D3 came out.
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The aperture is only set when you depress the shutter, until then the lens is at wide open for when it AFs other wise it would be too dark to AF. If you use a teleconverter you knock down the aperture a fair bit some lens without a wide aperture loose the ability to auto focus because they are too dark at minimum aperture I think it is about f8 when this happens.

Try it out set it to a really small aperture and fire off a shot while looking down the lens you'll see the aperture blades close up as the shot is taken.
 
Cuchulainn said:
It is letting in twice as much light - the lens will meter and autofocus wide open, so the maximum aperture is what is important. One small caveat is that not all bodies can use apertures wider than a given amount for extra metering efficiency or autofocus accuracy. From what I remember, Pentax uses an effective aperture of about f2 for focussing and metering irrespective of whether the lens is faster than this. Naturally, this is not the same as the imaging aperture, so you still get the benefit of the faster glass there.
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I see! learn something new every day.
 
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