# Thread: Calculating Shifted FOV and Equivalent Focal Length

1. ## Calculating Shifted FOV and Equivalent Focal Length

I guess this question has two parts: Is there a simple calculation that gives the 35mm equivalent for a lens on a larger format? For instance a 48mm lens on a 36x48mm sensor in 35mm equivalent? Is there a calculation that allows you to calculate the (horizontal) 35mm equivalent of the same lens on the same sensor when shifted, say, 10mm left then 10mm right?

I'm sure there must be, I just can't find it.

3. ## Re: Calculating Shifted FOV and Equivalent Focal Length

I authored both of the above tools and would be glad to answer any questions you have.

Just think about the sensor size increasing by the total amount of movement. +/- 10mm shift left/right results in 20mm wider effective sensor size.

4. ## Re: Calculating Shifted FOV and Equivalent Focal Length

Thanks Chris,

That does help.

Originally Posted by cly

5. ## Re: Calculating Shifted FOV and Equivalent Focal Length

Thanks Doug,

Just to confirm then, that with the DM33 which is a 48mm wide sensor, a 10mm shift left and right would give an overlap of 28mm in the calculator?

Originally Posted by dougpeterson
I authored both of the above tools and would be glad to answer any questions you have.

Just think about the sensor size increasing by the total amount of movement. +/- 10mm shift left/right results in 20mm wider effective sensor size.

6. ## Re: Calculating Shifted FOV and Equivalent Focal Length

Originally Posted by Pelorus
Thanks Doug,

Just to confirm then, that with the DM33 which is a 48mm wide sensor, a 10mm shift left and right would give an overlap of 28mm in the calculator?
That's correct.

Or you can use the DT calculator and next to the camera selector select 2-shots... 20mm between frames in which case you can play with horizontal vs vertical vs diagonal AOV (which becomes very important as you get more into pano formats like 2:1).

7. ## Re: Calculating Shifted FOV and Equivalent Focal Length

Originally Posted by dougpeterson
That's correct.

Or you can use the DT calculator and next to the camera selector select 2-shots... 20mm between frames in which case you can play with horizontal vs vertical vs diagonal AOV (which becomes very important as you get more into pano formats like 2:1).
Many thanks Doug. That's sorted it for me.