Need some AF tips

[480sparky]

Right. No autofocus system on a 500mm or longer lens can keep up.

So I guess I should just toss out all those shots I took at 500mm and longer as they're now out of focus?

Try it with kids playing football sometime, when you can't even see who has the ball, and everything is stacked up....what is the AF going to pick?

Easy. The one I tell it to.

I can do that because I know how the AF system and modes work on my camera.

 

[wfooshee]

It's going to pick what your SINGLE selected sensor is on.

If you're working with AF sensor groups, you have NO control over what gets picked. All of these bird shots posted had control of the focus because they used a single sensor and placed that sensor on the desired focus point of the image.

 

[Ornello]

Right. No autofocus system on a 500mm or longer lens can keep up.

So I guess I should just toss out all those shots I took at 500mm and longer as they're now out of focus?

Try it with kids playing football sometime, when you can't even see who has the ball, and everything is stacked up....what is the AF going to pick?

Easy. The one I tell it to.

I can do that because I know how the AF system and modes work on my camera.

See attached. It's easier when they break out....but sometimes a shadow ruins the shot!

 

[480sparky]

It's easier when they break out....

......whether you manually focus or use AF. The method is not relevant if you don't have a subject.

 

[Ornello]

Right. No autofocus system on a 500mm or longer lens can keep up.

So I guess I should just toss out all those shots I took at 500mm and longer as they're now out of focus?

Try it with kids playing football sometime, when you can't even see who has the ball, and everything is stacked up....what is the AF going to pick?

Easy. The one I tell it to.

I can do that because I know how the AF system and modes work on my camera.

How does the AF know which kid has the ball?

 

[480sparky]

How does the AF know which kid has the ball?

I tell it.

 

[Ornello]

How does the AF know which kid has the ball?

I tell it.

LOL. You're hilarious....

5 Situations When Manual Focus is Better than Auto Focus - Digital Photography School

10 Reasons to Turn off Your Autofocus - Digital Photography School

http://thepoliticalcarnival.net/wp-content/uploads/2013/02/cartman-hippies.jpg

 

[JacaRanda]

Ornello, what camera and lens combination are you using to shoot youth football?

 

[480sparky]

How does the AF know which kid has the ball?

I tell it.

LOL. You're hilarious....

5 Situations When Manual Focus is Better than Auto Focus - Digital Photography School

10 Reasons to Turn off Your Autofocus - Digital Photography School

http://thepoliticalcarnival.net/wp-content/uploads/2013/02/cartman-hippies.jpg

Well, apparently you have all the focus problems of the world figured out. Autofocus has no use in todays' craft. I'll just let you go about your merry way, manually focusing and nailing each and every shot perfectly.

However, let the rest of us go our ways, stupidly using AF. Some of us actually use our cameras instead of going to the Internet School of Photography.

 

[Ornello]

Ornello, what camera and lens combination are you using to shoot youth football?

560mm Leitz Telyt-R f/6.8. Leicaflex SL2. Fuji Pro 400 film.

This is the lens:

http://www.iscanmanuals.com/ebay/opticxchange/01032013pic170.jpg

Leica Telyt R 560mm 1:6.8 560/6.8 im Zubehörpaket mit Schulterstativ und Tasche

560mm telyt - Google Search

 

[Ornello]

How does the AF know which kid has the ball?

I tell it.

LOL. You're hilarious....

5 Situations When Manual Focus is Better than Auto Focus - Digital Photography School

10 Reasons to Turn off Your Autofocus - Digital Photography School

http://thepoliticalcarnival.net/wp-content/uploads/2013/02/cartman-hippies.jpg

Well, apparently you have all the focus problems of the world figured out. Autofocus has no use in todays' craft. I'll just let you go about your merry way, manually focusing and nailing each and every shot perfectly.

However, let the rest of us go our ways, stupidly using AF. Some of us actually use our cameras instead of going to the Internet School of Photography.

Well, it's winter now, and my gear is resting....

 

[480sparky]

Well, it's winter now, and my gear is resting....

What? You don't have any birds to manually focus on? They've all gone south?

 

[Ornello]

Well, it's winter now, and my gear is resting....

What? You don't have any birds to manually focus on? They've all gone south?

There are some geese hereabouts...

 

[wfooshee]

How does the AF know which kid has the ball?

I tell it.

LOL. You're hilarious....

5 Situations When Manual Focus is Better than Auto Focus - Digital Photography School

10 Reasons to Turn off Your Autofocus - Digital Photography School

http://thepoliticalcarnival.net/wp-content/uploads/2013/02/cartman-hippies.jpg

Yeah, he wasn't joking.

It also depends on the AF system in the camera. I had immense difficulties shooting an air show with my D5000 back in 2011. About 70-80% throw-aways for missed focus. No way to do the "pre-focus on a spot" at an air show, either.

Had a D7000 (same lens, though) for the 2012 show, shot 11 frames, not a single shot missed focus.

The other situations in your links, I agree with. Long exposure, low light, landscape, HDR, etc, focus manually (and consistently.) Giving it up for action shots, no way. Good AF can keep up.

As for "How does the camera know which kid has the ball?" you tell it. By pointing the one active AF sensor at that kid. That's what it focuses on.

Question, though. You say you're using a 40-year-old manual-focus film camera, and you're arguing against auto-focus. So what AF camera do you have that you've tried to shoot with in that situation? I'm asking because if you've not used AF, or have used AF on something like a P&S or a consumer-grade camera (like the D3000 or my old D5000) then you may be going on bad information. While I was using my D5000, I would have argued that AF was useless in action photography. My D7000 has told me otherwise.

Your camera has the split-image rangefinder in the viewfinder, so you KNOW when your subject is focused. AF cameras have ground glass only, no indication of precise focus. (Some have a focus LED that lights up, but you have to look around in the viewfinder and take your eye off your subject. Fast, precise manual focus is simply not possible with the OP's D7100. Your insistence that manual focus would be better for him is ludicrous, given what he's using. Also given what he's using, learning how AF works and knowing which mode to use, he should be able to get completely useful birding images.

 

[Ornello]

How does the AF know which kid has the ball?

I tell it.

LOL. You're hilarious....

5 Situations When Manual Focus is Better than Auto Focus - Digital Photography School

10 Reasons to Turn off Your Autofocus - Digital Photography School

http://thepoliticalcarnival.net/wp-content/uploads/2013/02/cartman-hippies.jpg

Yeah, he wasn't joking.

It also depends on the AF system in the camera. I had immense difficulties shooting an air show with my D5000 back in 2011. About 70-80% throw-aways for missed focus. No way to do the "pre-focus on a spot" at an air show, either.

Had a D7000 (same lens, though) for the 2012 show, shot 11 frames, not a single shot missed focus.

The other situations in your links, I agree with. Long exposure, low light, landscape, HDR, etc, focus manually (and consistently.) Giving it up for action shots, no way. Good AF can keep up.

As for "How does the camera know which kid has the ball?" you tell it. By pointing the one active AF sensor at that kid. That's what it focuses on.

Question, though. You say you're using a 40-year-old manual-focus film camera, and you're arguing against auto-focus. So what AF camera do you have that you've tried to shoot with in that situation? I'm asking because if you've not used AF, or have used AF on something like a P&S or a consumer-grade camera (like the D3000 or my old D5000) then you may be going on bad information. While I was using my D5000, I would have argued that AF was useless in action photography. My D7000 has told me otherwise.

Your camera has the split-image rangefinder in the viewfinder, so you KNOW when your subject is focused. AF cameras have ground glass only, no indication of precise focus. (Some have a focus LED that lights up, but you have to look around in the viewfinder and take your eye off your subject. Fast, precise manual focus is simply not possible with the OP's D7100. Your insistence that manual focus would be better for him is ludicrous, given what he's using. Also given what he's using, learning how AF works and knowing which mode to use, he should be able to get completely useful birding images.

I had the split-image + microprism replaced with plain microprism, on my SL2s. There was a special-order plain ground-glass available.