[ilkand]

Hi all,
Was just wandering what benefits IF (Internal Focusing?) would bring to a lens. Have bought a D70 body and want to add a lens or two. Is this feature any use to a beginner? It is on some nikon lenses but not others.

Thanks
Andy

[Dave]

Might be off the mark here, but is one advantage it stops the lens front rotating, which allows use of filter holder etc ?

[fingerz]

Yep, that's the main thing. Makes using polarising filters much easier.

[Steve]

Internal focusing in not exclusive to any one manufacturer, many use it. The beauty of internal focusing is that generally it allows movement of the glass elements within a contained area (the lens body) and so it is easier to keep the lens sealed. This is great for professionals or users that work in harsh environments. As Dave says as well, the front element of the lens will not rotate either, so that makes using certain filters (circular polarizers) mush easier as well.

[MyPix]

as above, but also the use of cutaway lens hoods to stop flare,

other advantages include near to silent focusing ( without the whirrr ) and also quicker focusing

the lens will also talk to the camera in a better fashion for some of the more complicated stuff like iTTL ,

the D70 can use conventional AF with a motor in the camera ( with the rotating peg ) or the new DX IF system which has the motor in the lens,

its another technical step forwrd

but something Canon has been doin for more than a decade ( motor in the lens bit )

if you get the chance, buy the newer glass, it will serve you better in the long run

MyPix

[Steve]

Originally Posted by MyPix

the lens will also talk to the camera in a better fashion for some of the more complicated stuff like iTTL ,

MyPix

I don't think I am following you here, I don't follow how internal focusing can improve communiction?

[fingerz]

Because there's no outside noise (like women gossiping, etc) to interfere with the communications

[MyPix]

what i mean is the focusing system is fully electronic untill the actual point of turning the glass, the pervious method was to turn the glass with the camera body motor and then comunicate its position via electronics back to the camera for TTL , then turn the glass a bit more to get it right ( or hunting )

having it all controled from one point provides more accurate faster AF , with a lot less hunting

[MyPix]

Originally Posted by fingerz

Because there's no outside noise (like women gossiping, etc) to interfere with the communications

or it could be that.....

MyPix, lmfao

[Arkady]

Biggest benefit is size - IF lenses are about 1/3 smaller and a bit lighter than the older non-IF optics.

More expensive though (or they were).

[MyPix]

Originally Posted by Arkady

Biggest benefit is size - IF lenses are about 1/3 smaller and a bit lighter than the older non-IF optics.

More expensive though (or they were).

i would agree in part...as my nikon lenses are smaller/lighter

but the sigma ones seem to have a bigger diamiter to them, but as stated smaller in length

MyPix

[Steve]

Originally Posted by MyPix

what i mean is the focusing system is fully electronic untill the actual point of turning the glass, the pervious method was to turn the glass with the camera body motor and then comunicate its position via electronics back to the camera for TTL , then turn the glass a bit more to get it right ( or hunting )

having it all controled from one point provides more accurate faster AF , with a lot less hunting

Ahh it all makes sense now

I didn't know that Nikon used/use motors inside the camera body to focus the lens, when did they change that or is it still in use on certain ranges and how does that effect lense compatibilty where some (presumably) lenses have internal motors as well?

[MyPix]

i dont know about the newr D200 etc, but all the AF bodies since film have a servo AF motor in the camera body ( spring loaded to retract while fitting a lens, when off the camera and the focusing ring was turned a small gear could be seen on the bayonet collar turning at the same time

newer lenses with internal motors dont have this gear , and the electronics within must tell the camera this fact

this was always a factor in the Nikon/Canon comparison, as Canons focused quicker in most situation due to the internal motors in the lens, well it was a known problem when i bought a Nikon F601, compared to the Canons of the same era , early 1990's

MyPix

[MyPix]

out of curiosity i just fitted a DX IF lens on my F601 film camera....the AF didnt work,
so one can asume that the newer camera is backward compatable to older lenses ( mechanical AF ), but you cant put IF lenses on mechanical AF camera's.

MyPix

[ilkand]

Look at all these replies - this forum is brilliant, cheers.

it stops the lens front rotating,

So If I use a ND grad , I won't need that whole filter holder assembly thing for the front, like Cokin make? Looks a bit Heath Robinson that. Does anybody use one?

Andy

[MyPix]

i use mine....its stopin the table from wobbling, lol

MyPix

[Steve]

Originally Posted by ilkand

Look at all these replies - this forum is brilliant, cheers.


So If I use a ND grad , I won't need that whole filter holder assembly thing for the front, like Cokin make? Looks a bit Heath Robinson that. Does anybody use one?

Andy

If you buy a screw in one you wont, but unless all your lenses have the same size screw thread then you will only be able to use that filter on that lens. The beauty of the Cokin system is that you can just by cheap adaptor rings to all you to use the same system and expensive filters on all your lenses.

[ilkand]

but unless all your lenses have the same size screw thread then you will only be able to use that filter on that lens

I've seen suggestions to get an adaptor ring that screws in and then use the same (72mm? pro) filters. Is this less bulky, or just a similar tpye of product?

Andy