Full Time Manual Focus

[FrancisGabriel]

Hi,

Can someone explain to me the above term?

Understand that some lens have it andsome doesn't.

Thank you.

 

[J-Chan]

Simply means you can manual focus the lens anytime by just turning its focusing ring, so you don't really need to switch from AF to MF..

 

[FrancisGabriel]

Simply means you can manual focus the lens anytime by just turning its focusing ring, so you don't really need to switch from AF to MF..

What about those lens that is without full time manual focusing? What will happen if you accidentally turn the focusing ring while on AF mode?

 

[Octarine]

What about those lens that is without full time manual focusing? What will happen if you accidentally turn the focusing ring while on AF mode?

First you will notice that it is quite tight due to the gear system between focus ring and focus motor. Secondly those lenses tend to have a very small AF ring at a position where you hardly touch it accidentally (check all kit lenses). Not much room for 'accidental' moving. If your camera is on AF Servo mode it will readjust the focus. Single Shot mode will be out of focus.

 

[FrancisGabriel]

Thank you so much. Learn something again today!!

So even if accidentally turned the focusing ring, will it cause any harm to the lens? If it does, It could be something to look at when buying 2nd hand lens without full time manual focusing?

 

[yc2005]

Thank you so much. Learn something again today!!

So even if accidentally turned the focusing ring, will it cause any harm to the lens? If it does, It could be something to look at when buying 2nd hand lens without full time manual focusing?

Yes, you will spoil the motor inside the lens.
When buying 2nd hand lens, definitely you need to test the AF of the lens.. Do a search for what to look out for when buying a used lens (hint: its a sticky thread)

 

[allenleonhart]

Yes, you will spoil the motor inside the lens.
When buying 2nd hand lens, definitely you need to test the AF of the lens.. Do a search for what to look out for when buying a used lens (hint: its a sticky thread)

yep. this is quite common in photography. ftm is an advantage. as we all know, af can only focus at a point. it gives a rough idea where the actual focus shld be. however, once u subject moves, the focus will be difference and u need to auto focus again. and its tough

ftm offers teh advantage, where one could override the af and manually focus, so u use ur af to bring u to a rough focus, then u go on to do the minor adjustments.

 

[FrancisGabriel]

Yes, you will spoil the motor inside the lens.
When buying 2nd hand lens, definitely you need to test the AF of the lens.. Do a search for what to look out for when buying a used lens (hint: its a sticky thread)

Mean to say so long as the lens can still auto focus then shouldn't be sn issue is it?

 

[FrancisGabriel]

yep. this is quite common in photography. ftm is an advantage. as we all know, af can only focus at a point. it gives a rough idea where the actual focus shld be. however, once u subject moves, the focus will be difference and u need to auto focus again. and its tough

ftm offers teh advantage, where one could override the af and manually focus, so u use ur af to bring u to a rough focus, then u go on to do the minor adjustments.

Thanks, now I have a better understanding what is ftm focusing is for.

 

[allenleonhart]

Mean to say so long as the lens can still auto focus then shouldn't be sn issue is it?

not really. the af would work, but its either slower, or its less accurate. once motor is damaged, u will noticed that its not as strong during focusing.

 

[heshanj]

hmm, so full time manual focus means that u can completely manual focus even when AF is on? i was under the impression that u can only make small corrections to AF with full time manual
thanks