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A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 10:30 pm
by Alex
Hi all,

This is a stupid question, but as someone who's never used anything but the kit lens and 70-300 G I am a bit puzzled.

I just purchased a 2nd hand Nikkor AF 28mm 2.8f lens. I see aperture and focust rings and I understand how they function.

Just where the window with distances is there is a bar, which I guess needs to coincide with the aperture ring settings to show aperture (with D70 not required as f is controlled by d70 itself). To the left of the bar is a dot (I guess this needs to be matched with the distance numbers for maual focusing).

My question, however is: What do the aperture(?) numbers 22 16 11 to the either side of the bar represent and what is their function (if any). I know it's probably a very basic question for someone, but I never had a lens like that.

Thanks in advance....

Alex

P.s. a hell of a quesiton for someone with a 'senior member' status :oops:

PostPosted: Thu Sep 01, 2005 10:38 pm
by spartikus
From what I know, you have to set the aperture as wide open as possible with the ring i.e. 22 on the scale, and then the D70 will take care of everything else. This is certainly the case with some older lenses, my D70 just spews out errors otherwise.

Could be wrong though, anyone else?

Re: A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 10:42 pm
by genji
Alex wrote:My question, however is: What do the aperture(?) numbers 22 16 11 to the either side of the bar represent and what is their function (if any). I know it's probably a very basic question for someone, but I never had a lens like that.

Thanks in advance....

Alex

P.s. a hell of a quesiton for someone with a 'senior member' status :oops:


Alex

the 11, 16, 22 are aperture numbers relating to DOF, ie when you set the apeture to f11 and focus on an object, look at the distance marker and the distance between the 16 is the distance in focus

cheers
tai

Re: A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 11:08 pm
by Alex
genji wrote:
Alex wrote:My question, however is: What do the aperture(?) numbers 22 16 11 to the either side of the bar represent and what is their function (if any). I know it's probably a very basic question for someone, but I never had a lens like that.

Thanks in advance....

Alex

P.s. a hell of a quesiton for someone with a 'senior member' status :oops:




the 11, 16, 22 are aperture numbers relating to DOF, ie when you set the apeture to f11 and focus on an object, look at the distance marker and the distance between the 16 is the distance in focus

cheers
tai


Alex

Thanks guys.

Tai. This is very useful. It's like a manual DOF preview. Thanks very much. It's clear now.

Alex

PostPosted: Thu Sep 01, 2005 11:10 pm
by krpolak
Going futher into primes you can find Hyperfocal Distance as an usefull tool. However with AF lenses I don't use it that much. Uselly I choose my focusing point keeping in mind chosen apperture and in consequence DOF. Once I got focus right I compose my framing.

More details about Hyperfocal can be found here:

http://www.dofmaster.com/hyperfocal.html#focusing

Have fun with primes Alex :)

Regards,

K.Polak

PostPosted: Thu Sep 01, 2005 11:10 pm
by MattC
This article could be useful.

http://www.luminous-landscape.com/tutor ... /dof.shtml

Cheers

Re: A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 11:12 pm
by Doughnut
Alex wrote:<snip>
To the left of the bar is a dot (I guess this needs to be matched with the distance numbers for maual focusing).
<snip>


Hi,
I may be wrong here but I think this dot is the Infra-Red compensation index.

Cheers,
Edward

Re: A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 11:13 pm
by Alex
Doughnut wrote:
Alex wrote:<snip>
To the left of the bar is a dot (I guess this needs to be matched with the distance numbers for maual focusing).
<snip>


Hi,
I may be wrong here but I think this dot is the Infra-Red compensation index.

Cheers,
Edward


Hmm.. sorry. What does IR compensation index do?
Thank you

Alex

Re: A stupid lens quiestion

PostPosted: Thu Sep 01, 2005 11:29 pm
by MattC
Alex wrote:Hmm.. sorry. What does IR compensation index do?
Alex


It is used to compensate the focus for black and white infrared film.

How it works, I have no idea. :D

Cheers

PostPosted: Fri Sep 02, 2005 11:21 am
by Alex
krpolak wrote:Going futher into primes you can find Hyperfocal Distance as an usefull tool. However with AF lenses I don't use it that much. Uselly I choose my focusing point keeping in mind chosen apperture and in consequence DOF. Once I got focus right I compose my framing.

More details about Hyperfocal can be found here:

http://www.dofmaster.com/hyperfocal.html#focusing

Have fun with primes Alex :)

Regards,

K.Polak


Thanks for the link, Krystian. Looks interesting.

Cheers
Alex

PostPosted: Fri Sep 02, 2005 11:22 am
by Alex
Matt,

Thanks for the link.

Cheers
Alex