focal length

Gorbsteruk

Gorbsteruk

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Mike
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Please could you advise me on the focal length of my d90 , I am trying to get my head around it , would I be right in saying that if my 18-105mm lens is fully extended to 105mm if I times it by (1.5x) the actual focal length of my lens will be 157.5mm ? if this is correct when I put the data of what I shot my photo at (exif data ) do I put 105mm as my lens states or do I have to add on the 1.5x , Hope that makes sence of what i'm trying to ask :)


mike
 
The exif should be present out of the camera, not sure why your having to add it?

On my D50 I get 2 fields: actual focal length and also a 35mm equivalent (so actual x 1.5).
 
Hi

The focal length remains unchanged, it is solely a property of the lens. If you have a crop factor camera the effective focal length has changed, well its really the field/angle of view that the is accurate description.

If you were going to appended EXIF info directly onto the image or border for example and you also included the camera body, then most folk will be able to determine the effective focal length from that.

EDIT - Therefore I would put D90 @ 105mm


Andy
 
Last edited:
AndyB1976 said:
Hi

The focal length remains unchanged, its is solely a property of the lens. If you have a crop factor camera the effective focal length has changed, well its really the field/angle of view that is accurate description.

If you were going to appended EXIF info directly onto the image or border for example and you also included the camera body, then most folk will be able to determine the effective focal length from that.

EDIT - Therefore I would put D90 @ 105mm


Andy
Click to expand...

Thank you I was just unclear as what to put Its all new to me and very confusing at times but I am getting there .

mike:thumbs:
 
It's a common misconception. The x 1.5 crop factor doesn't turn a 105mm lens into a 157mm, it's still a 105mm but has the same field of view as a 157mm on full frame or a 35mm film camera.
 
MartynK said:
It's a common misconception. The x 1.5 crop factor doesn't turn a 105mm lens into a 157mm, it's still a 105mm but has the same field of view as a 157mm on full frame or a 35mm film camera.
Click to expand...

BandyQuill said:
it doesnt make your lens longer, it just gives you the equivalent field of view as a 157mm lens...
Click to expand...

That makes it much clearer in my mind, Thank you, I'm sure I will have many more questions :thumbs:

mike
 
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