The Basics of Lens Focal Length: FocusEd


In this week’s video, FocusEd discusses lens focal length for photographers. You will learn about what focal length is, how sensor size and lens focal length affects your angle of view, and more!

For more on Focal Length, check out this article.





Loved the video, very informative but also entertaining. You're doing god's work guys. 

For some reason the video isnt playing

I really appreciate that small bit of information and look forward for your next lesson.

Hi Larry

Interesting video except you left out an important reason on how or why advanced amateur and professional photographers use these numbers. If I'm taking a portrait of someone and I frame the subject in a specific manner, (as demonstrated in your video) why would I choose a 35mm lens over a 105mm lens? According to your video it's compression of the background (or foreground) vs subject. But the 3 sample photos that were shown I was hard pressed to see much difference (other than the background island getting bigger) so I have to disagree. Your audience doesn't know (or necessarily care) where a background object(s) is(are) in relation to the subject, nor are they aware how large an object is (again as demonstrated in your those 3 examples). In my opinion the more important reason for focal length choice is the depth of field. An experienced photographer will want to control what is in focus and what is not using DoF with all other factors being equal (ISO, shutter speed and F stop). There will be times where adjusting F-stop/shutter speed for DoF control can't achieve the desired result.

An example of focal length choice for the 35mm (full frame) format is a lens in the 85 - 105mm focal length range called a "portrait lens". The photographer will have a good working distance from the subject, control of the framing of the subject's face and at the same time keeping the background out of focus minimizing distracting content. There are other instances of focal length adjustment like a TS lens that allow creative image capture that was impossible prior to digital manipulation. But I digress here. I just think that focal length is mostly mis-understood by newbies and veteran camera people alike. This is especially obvious when a photographer wonders why they can't get the same results with smaller format cameras. It's not the angle of view that's the problem but the focal length. This concept should be taught at the outset when folks become interested in photography.

I hope this makes sense.


Concise, informative and applicable.  Will apply terms more knowingly. Thanks

Question:  when using a tripod to what degree does IS OFF matter?

The information in this video was great - thanks.  The way it was cut (all those choppy zoom cuts) and the pace was distracting!  If you are concerned about the length, maybe make a two part series?  I wanted to be able to see the "compression" artifacts (background appears to come forward with increase in focal length) but that section went by so fast I didn't have time to scan left and right to see the difference.  I know I could pause, but then I'm not hearing what you are saying.   Anyway, great video, but a little frenetic.