AF Questions - Such as "Why?"

[robertdrake]

I've been using a Canon A-1 for nearly thirty years, and I don't get the appeal of Auto Focus lenes. Why would I want one? Can I get Canon lenses for a 20D that are not autofocus? If so, are they cheaper?

I assume I can turn an AF lens off?

[CyberDyneSystems]

You can turn AF off on most lenses..

Canon no longer makes any non AF lenses except for the MPE65 "super Macro"

Canon's older Manual lenses "FD" can not be easily adapted to function on the EOS AF bodies.

[mdude85]

maladjustment of the dioptic on SLR camera viewfinders may lead to a subject that appears in focus when you move the ring, but ends up out of focus when viewed on a screen. better let the camera do the thinking, because it operates independent of the dioptic.

this is just one of many reasons .....

[DocFrankenstein]

Modern digital cameras don't have the "light splitting sircle" :oops: like old film cameras do. It's really hard to get the autofocus right.

But on the other hand, you'd be able to use most of m42 and other old manual lenses if you really don't like the AF.

[Penguin_101_1]

Modern digital cameras don't have the "light splitting sircle" :oops: like old film cameras do. It's really hard to get the autofocus right.

But on the other hand, you'd be able to use most of m42 and other old manual lenses if you really don't like the AF.
My modern 80's camera has it????

[robertdrake]

Modern digital cameras don't have the "light splitting sircle" :oops: like old film cameras do. It's really hard to get the autofocus right.

No focuing aids in the viewfinder? Or just the split circle?

But on the other hand, you'd be able to use most of m42 and other old manual lenses if you really don't like the AF.

What is "m42" lens?

[robertdrake]

maladjustment of the dioptic on SLR camera viewfinders may lead to a subject that appears in focus when you move the ring, but ends up out of focus when viewed on a screen. better let the camera do the thinking, because it operates independent of the dioptic.

this is just one of many reasons .....

Good point. Not even sure how to use dioptic adjustments, and my I'd probably need to given that my eyesight isn't what it was 30 years ago.

[robertwgross]

On all of the modern EF lenses, there is a manual/automatic focus switch. So, if you don't like what the camera and lens are trying to do automatically, you can always switch it to manual

Or, if you don't like autofocus, then stick on a Canon 2x teleconverter to a typical lens. That will inhibit autofocus.

If you have a good clear subject, then autofocus will get it right most of the time, and it happens much quicker than you could manually focus it. On the other hand, if you have a poorly lit subject with poor contrast, then autofocus might struggle around and get it badly. Well, OK, do manual focus then.

---Bob Gross---

[Ballen Photo]

Modern digital cameras don't have the "light splitting sircle" :oops: like old film cameras do. It's really hard to get the autofocus right.

No focuing aids in the viewfinder? Or just the split circle?

But on the other hand, you'd be able to use most of m42 and other old manual lenses if you really don't like the AF.

What is "m42" lens?

The m42 is just the standard 42mm threaded "Screw in" lens. :shock:
In THOSE days, the screw in lenses were interchangable between different manufacturers camera bodies, as they all seemed to use the m42 size. :wink:
-Bruce

[DocFrankenstein]

No focuing aids in the viewfinder? Or just the split circle?
I am not sure what you mean by the focusing aids, but the split circle isn't available for sure.

[Hellashot]

Whenever I can I use manual focusing. Why would I want my camera to get credit for my pictures? :)

Hellashot

[robertdrake]

Whenever I can I use manual focusing. Why would I want my camera to get credit for my pictures? :)

Hellashot

Right! We might just as well send the camera out to take the pictures and stay home...that's what its coming to. How does the camera know what I want to focus on?

[defordphoto]

So, keep your A-1 and move on...

Just curious, and not wanting to raise the hairs on the back of your neck; Why did you even post here? This is a digital forum...

[nosquare2003]

No focuing aids in the viewfinder? Or just the split circle?
I am not sure what you mean by the focusing aids, but the split circle isn't available for sure.

The EOS 1 bodies would have the choice to change to a focus assist split screen.

Set the EF lens to manual focus and you will get a manual focus DSLR...

[robertdrake]

No focuing aids in the viewfinder? Or just the split circle?
I am not sure what you mean by the focusing aids, but the split circle isn't available for sure.

Microprism and or cross-hatch. My A-1 has both.

[quote]So, keep your A-1 and move on...

Just curious, and not wanting to raise the hairs on the back of your neck; Why did you even post here? This is a digital forum...

I know that. A digital does offer some features I find useful, I just don't need the thing to do my focusing for me, or lots of other lazy features.

[robertwgross]

How does the camera know what I want to focus on?

It assumes that when you put the autofocus box on something, then that is what it is going to try to autofocus on.

---Bob Gross---

[djtowle]

You can turn AF off on most lenses..

Canon no longer makes any non AF lenses except for the MPE65 "super Macro"



And the 3 tilt/shift lenses.

[steven]

My 1Ds has the option of changing focusing screen that has both the micro prisim as well as the split image.

Just depends on the camera.

[CyberDyneSystems]

You can turn AF off on most lenses..

Canon no longer makes any non AF lenses except for the MPE65 "super Macro"



And the 3 tilt/shift lenses.

You know I had typed "the tilt shift lenses" at first but then I was unsure.. and too lazy to double chaeck :)

[CyberDyneSystems]

....A digital does offer some features I find useful, I just don't need the thing to do my focusing for me, or lots of other lazy features.

I use Manual focusing when the scene requires it and I have time to make the shot and not be so lazy...

There are times however.. most of the time for me and the type of shooting I do. where AutoFocus,. and even auto exposure modes make or break the chances of getting the shots.

It's all a matter of what you are shooting and how much time your subject gives you to do it.

[robertdrake]

....A digital does offer some features I find useful, I just don't need the thing to do my focusing for me, or lots of other lazy features.

I use Manual focusing when the scene requires it and I have time to make the shot and not be so lazy...

There are times however.. most of the time for me and the type of shooting I do. where AutoFocus,. and even auto exposure modes make or break the chances of getting the shots.

It's all a matter of what you are shooting and how much time your subject gives you to do it.

That's true when I'm shooting action shots, but I'm pretty fast at focusing. My only experience with auto focus is my A75, which is just awful (and not just with auto focus either). No doubt, a good DSLR should greatly outperform the A75's AF capabilities. But I also do still shots, for which I would want to use manual focus, and from what I've read here, there is no problem doing that with the 20D.

[nosquare2003]

But I also do still shots, for which I would want to use manual focus, and from what I've read here, there is no problem doing that with the 20D.

I haven't followed the threads with 20D. But I "believe" that there is no focus assist screen in 20D. Moreover, it is difficult for some EF lenses to do manual focus because their coarse adjustment.

Anyway, I understand why you prefer manual focus. However, Canon's autofocus system is good and you may change...

[Ballen Photo]

My only experience with auto focus is my A75, which is just awful (and not just with auto focus either). No doubt, a good DSLR should greatly outperform the A75's AF capabilities.

If you've never used a prosumer Canon autofocus film SLR(especially) or digital DSLR, then you are in for a treat. Once you get used to how it functions, it seems to be in focus almost by merely "Thinking" it so. :shock: If you want to focus say, on the second or third Horse or whatever just past the first one, you simply put the Red rectangle over it. I've disabled all the focus points except for the middle one on my 10D, and once I've grabbed focus with it, I simply recompose without really even thinking too hard about it. This works best for me, and to coin a phrase, "Your mileage may vary".
In film, everything from the old Elans, A2's, and "1" series were extremely fast as long as you used a decent lens.
In digital, the top end EOS, and especially Canons "D1" series are known as "The Fastest" cameras on this planet.
Dont let the A75's slow focus speed disuade you, it's probably about like my G-5, and YES, it IS slow to focus.
Bear in mind too, that I cut my teeth on manual focus cameras. :shock:
-Bruce

[Tom W]

Whenever I can I use manual focusing. Why would I want my camera to get credit for my pictures? :)

Hellashot

Well, so people can say "you must have a really nice camera!" :)

[maderito]

I've been using a Canon A-1 for nearly thirty years, and I don't get the appeal of Auto Focus lenes. Why would I want one? Can I get Canon lenses for a 20D that are not autofocus? If so, are they cheaper?

I assume I can turn an AF lens off?
This reminds me of the time a few years back when I was so used to driving cars without power steering that I insisted that I wanted my new car with manual steering - so that I could still stay in touch with the road. An indulgent car dealer gently led my thoughts, habits and opinions into the present and away from the past - thankfully.