[haring]

- Is focus trap a feature of the lens or the camera? I am sorry if the question is too basic.-

- Is there a list of DSLRs I can use "focus trap" with? Canon, Nikon, Sony, Leica, Mamiya, Hasselblad, etc...?

- Can I use with any lens on cameras which capable of the focus trap feature?



I have a few old manual lenses and it would be great to focus on moving subjects...



Thanks a lot!

[Brightcolours]

[quote name='haring' timestamp='1302697028' post='7593']

- Is focus trap a feature of the lens or the camera? I am sorry if the question is too basic.-

- Is there a list of DSLRs I can use "focus trap" with? Canon, Nikon, Sony, Leica, Mamiya, Hasselblad, etc...?

- Can I use with any lens on cameras which capable of the focus trap feature?



I have a few old manual lenses and it would be great to focus on moving subjects...



Thanks a lot!

[/quote]

You can not focus trap with Canon EOS cameras, at least not with the "low end" ones. I do not know if the 1D series behave differently. The Canons do not offer "focus priority" without auto focus. I think with Nikon you can, although I do not know if all models behave the same. Whether you can actually focus trap with old MF lenses with Nikons I do not know. It may well be that the AF sensor will not be active without lenses with the right electronics.

[mst]

To my knowledge, it's a dedicated feature on some Canon cameras (not sure which, though). I must admit that I'm not sure if it's a feature on any Nikon camera (read: if there is a dedicated menu entry called "focus trap"), but you can egt the same effect with any Nikon that allow to assign AF to a dedicated button on the rear and offer focus priority in AF-S (Single Shot, not Silent Wave) mode. With such a setup, focus where intended, press the shutter button, wait for subject to move in focus, camera releases.



This should be possible with any lens on a Nikon. On a Canon camera, it may require an AF confirmation chip in the lens.



-- Markus

[Brightcolours]

[quote name='mst' timestamp='1302697873' post='7595']

To my knowledge, it's a dedicated feature on some Canon cameras (not sure which, though). I must admit that I'm not sure if it's a feature on any Nikon camera (read: if there is a dedicated menu entry called "focus trap"), but you can egt the same effect with any Nikon that allow to assign AF to a dedicated button on the rear and offer focus priority in AF-S (Single Shot, not Silent Wave) mode. With such a setup, focus where intended, press the shutter button, wait for subject to move in focus, camera releases.



This should be possible with any lens on a Nikon. On a Canon camera, it may require an AF confirmation chip in the lens.



-- Markus

[/quote]

With Canon, you probably will need an 1D series, as you need to be able to set focus priority, which is linked to single shot AF with most models. So... without AF, no focus priority.

[mst]

I think it was a dedicated feature (a Custom Function) on the initial and Mark II models of the 1D/1Ds. Not sure if it's still available in current Mark III and Mark IV cameras.



But yes, you will need AF confirmation for this to work. Which means: a chipped lens.



-- Markus

[DrJohn]

There is an easy workaround which should apply to any Canon camera and any AF lens:



http://translate.google.de/translate?u=http%3A%2F%2Fwww.matzew.com%2F2011%2F02%2F11%2Ftrap-focus-fokusfalle-auch-bei-kleinen-canon-modellen%2F&sl=de&tl=en&hl=&ie=UTF-8



For MF lenses and Canon, you need at least an adapter with an AF chip, but I'm not sure if the above trick will work at all.

EDIT: Most likely, it won't work with a chip since such a chip tells the camera that there is an AF lens in MF switch position. For the trick, you need the switch to be in the AF position.



By the way: Which MF lenses do you have? Are you aware that you cannot adapt all lenses to all systems?

[popo]

Just looked for the feature on the 1D. I think it might be Personal Function 16. P.Fn are different from custom functions in that you have to set them connected to a computer.



The exact description of P.Fn 16: Enables automatic shooting when focus is achieved at the fixed point of focus while the shutter button is fully pressed.



BUT to me that description could also fit a "focus priority" continuous AF so I'm not 100% sure if that is it. e.g. when I had the Sony A350 I remember the default behaviour in continuous AF mode is that the shutter only releases when it thinks it has focus.

[frank]

[quote name='mst' timestamp='1302697873' post='7595']

To my knowledge, it's a dedicated feature on some Canon cameras (not sure which, though). I must admit that I'm not sure if it's a feature on any Nikon camera (read: if there is a dedicated menu entry called "focus trap"), but you can egt the same effect with any Nikon that allow to assign AF to a dedicated button on the rear and offer focus priority in AF-S (Single Shot, not Silent Wave) mode. With such a setup, focus where intended, press the shutter button, wait for subject to move in focus, camera releases.



This should be possible with any lens on a Nikon. On a Canon camera, it may require an AF confirmation chip in the lens.



-- Markus

[/quote]



Markus, may I have two questions (for focus trap with Nikon, e.g. D700):



1. Will this method work with a manual-focus lens also?



2. How is this method compared to the AF-C focus mode?



Thanks,

Frank

[netrex]

AFAIK, all Pentax cameras can do this. At least the K10D, K-x and K-5 which I've owned and own now, and they could do it. It also worked and works great.

[PuxaVida]

[quote name='haring' timestamp='1302697028' post='7593']

- Is focus trap a feature of the lens or the camera? I am sorry if the question is too basic.-

- Is there a list of DSLRs I can use "focus trap" with? Canon, Nikon, Sony, Leica, Mamiya, Hasselblad, etc...?

- Can I use with any lens on cameras which capable of the focus trap feature?



I have a few old manual lenses and it would be great to focus on moving subjects...



Thanks a lot!

[/quote]



For a Nikon with AF lenses;



- set the AF activation to "AF-ON only",

- push the shutter release all the way down and keep it there,

- wait for the moving subject to get trapped in focus plane...



the shutter will be released and voila! you get your photo in perfect focus.



Serkan