What exactly do the 'mm's' stand for on the lenses? Hi, Excuse me for such a ridiculously silly question... I know it is already, but cannot find the actual answer to this anywhere.

Emma1979 Loc: Western Australia

Hi,

Excuse me for such a ridiculously silly question... I know it is already, but cannot find the actual answer to this anywhere.

What exactly do the mm's stand for on the lenses? For example a 50mm, a 70-300mm or a 10-24mm per se?

Thanks Emma

Mallardo Loc: NW Louisiana

Hi, Emma. The "mm' stands for millimeter.

Emma1979 Loc: Western Australia

Yes lol. I know mm stands for millimetre and cm centimetre etc, apologies I didn't make myself clearer.

What does it actually mean though? What is a 50mm lens, does it mean I have to be at least 50mm away from the subject?

selmslie Loc: Fernandina Beach, FL, USA

Emma1979 wrote:

Yes lol. I know mm stands for millimetre and cm centimetre etc, apologies I didn't make myself clearer.

What does it actually mean though? What is a 50mm lens, does it mean I have to be at least 50mm away from the subject?

This forum might not be the best place for such a fundamental question. Almost any basic book on photography will cover what you need to learn about lens focal lengths, etc.

If you are too far from a library or bookstore, you could start with: http://www.cambridgeincolour.com/tutorials/camera-lenses.htm

Db7423 Loc: Pittsburgh, PA

Hi Emma, see: http://www.digital-photo-secrets.com/tip/215/what-does-the-mm-mean-on-a-lens/# -for a good answer to your question.

Emma1979 Loc: Western Australia

Selmslie - I have read many 'basic' photography books and have never found a satisfactory answer. I have also searched google where the only answer I have found is what the lens actually does. For example wide/macro etc. No question should be seen as too stupid if you genuinely want to assist ppl to become more comprehensive photographers. Please don't be so condescending, it really isn't necessary. Thank you for your response and I will check out the link.

Thank you very much Db.

Danilo Loc: Las Vegas

Hi Emma! 50mm, or 85mm, etc. is the "focal-length" of a lens. Focal length is a measurement from the sensor in your camera, forward to a mysterious place (optical axis) in the middle of your lens. It's most useful in telling you the approximate "field of view" a given lens will render. For example: a 50mm lens on a 35mm camera renders roughly a 45 degree angle of view. A lens with a lower # measurement (28mm, 24mm) will have a wider field of view, and a larger # (85mm, 200mm) will have a narrower field of view.
Just as a basic rule, if you want to photograph a wide area view of something (landscape, for example) you may wish to grab a lens with a small mm # (20mm, 24mm).
DO NOT, under any circumstance, stop asking questions!

Db7423 Loc: Pittsburgh, PA

Emma1979 wrote:

Selmslie - I have read many 'basic' photography books and have never found a satisfactory answer. I have also searched google where the only answer I have found is what the lens actually does. For example wide/macro etc. No question should be seen as too stupid if you genuinely want to assist ppl to become more comprehensive photographers. Please don't be so condescending, it really isn't necessary. Thank you for your response and I will check out the link.

Thank you very much Db.

Emma, hope the link was what you were looking for. As you can see your question doesn't lend itself to an easy (comprehensive) answer. Now regarding your question- it was not stupid- asking questions is one of the primary ways people learn and answering questions and discussing problems is what the Forum is for.

ioptfm Loc: Isle of Palms, SC

I agree that no question should be below the advice on this forum....Some are more into photography than others and all should realize that at one time or another all were considered a novice

Nikonian72 Loc: Chico CA

Danilo wrote:

50mm, or 85mm, etc. is the "focal-length" of a lens. Focal length is a measurement from the sensor in your camera, forward to a mysterious place (optical axis) in the middle of your lens.

Bingo! Well stated.

Comparison photos here: http://www.uglyhedgehog.com/t-7776-1.html

mdorn Loc: Portland, OR

Danilo wrote:

Hi Emma! 50mm, or 85mm, etc. is the "focal-l... (show quote)

:thumbup:

SharpShooter Loc: NorCal

Emma1979 wrote:

What exactly do the m&m's stand for on the lenses? For example a 50mm, a 70-300mm or a 10-24mm per se?
Thanks Emma

Emma, not rediculous at all.
But first it depends on whether you are talking chocolate, peanut or glass!?
Actually Danilo did a fine job on the glass ones.
Just don't ask why a 600mm telephoto is only 450mm long and everything will be OK.
Emma thanks, I've been waiting two years for someone to ask about M&Ms. Again, thanks

Linda From Maine Loc: Yakima, Washington

selmslie wrote:

This forum might not be the best place for such a fundamental question. Almost any basic book on photography will cover what you need to learn about lens focal lengths, etc.

And who made you, selmslie, the expert on what level of assistance people should be able to request on this site? Gheesh.

RTR Loc: West Central Alabama

Emma, keep asking those questions. Sometimes you run into someone on the boards who 'just don't get it'.

Danilo and Nikonian72, good answers :)

Linda From Maine Loc: Yakima, Washington

Danilo wrote:

Hi Emma! 50mm, or 85mm, etc. is the "focal-l... (show quote)

Maybe helpful also to relate the mm to our own vision: 50mm on that old film camera* is basically what we see straight ahead and without assistance; any number less than that (wide angle) would require us to turn our heads, or at least swivel our eyes, to take it all in; the numbers higher than 50 are like telescopes: bringing something closer than we can see with the naked eye. (*the numbers have changed a bit with digital cameras.)