Everything You Didn’t Know About Your Camera Lenses

by Bret Hoy2 Comments

The camera world is never simple. Never at all. Nowhere else is this more apparent than when you consider lenses, sensors and how they’re used. What’s so easy to forget is that they’re complicated devices that require precise engineering.

The centuries of engineering and science that’s gone into modern optics should never be discounted, and this video, posted by FilmmakerIQ explains exactly why we shouldn’t be taking it for granted.

What’s so interesting about this video is about how much science goes into the basic information of the lens world. Things like apertures become ingrained into your head after you’ve shot long enough, and when that happens you tend to forget they ACTUALLY mean something.

The science and methodology behind the numerical system of apertures was very enlightening, as was the explanation of T-Stops, which I thought I understood.

Hearing what John Hess had to say about it further showed me just how important the T-Stop is to the cinematography world.

Also I love that he discussed the Split-Diopter. Very few people in the photography and cinematography community nowadays even remember that these exist, let alone their use. While I don't really like the effect they have on a picture, it shouldn't be forgotten.

Not only has John Hess and FilmmakerIQ given all kinds of great information about lenses, they’ve gotten me excited about experimenting with them again. Now I want to go back to school and learn more about optics.

The Properties of Camera Lenses

FilmmakerIQ's Introduction to the Properties of Camera Lenses

Via Fstoppers:

John P. Hess, over at FilmmakerIQ.com has launched a second video about lens technology this week. This time dealing with the properties of camera lenses. The information contained relates to both still photography and cinematography, and also details the subtle differences between the two as they relate to lenses. He covers topics such as focal length, aperture (or iris), the differences between primes and zooms, and even a look at anamorphic and parfocal lenses.

Read full article at Fstoppers “FilmmakerIQ's Introduction to the Properties of Camera Lenses”

Note: it is our policy to give credit as well as deserved traffic to our news sources – so we don't repost the entire article – sorry, I know you want the juicy bits, but I feel it is only fair that their site get the traffic and besides, you just might make a new friend and find an advertiser that has something you've never seen before

(cover photo credit: snap from video)


  1. This is a good (but not great) introduction. I was impressed, though, with the excellent discussion of diffraction.
    Mr Hess makes a number of errors.
    >> He misuses the terms “zoom” and “telephoto”.
    >> He repeatedly confuses “as large as” with “larger than”.
    >> He does not correctly explain what a fisheye lens is.
    >> Prime lenses inherently change “focal length” as they are (bodily) focused. It is not the result of poor design.
    >> OIS and IS aren’t the same thing. All OIS is IS,, but not all IS is OIS.
    >> Bokeh is not pronounced “bow-kay”. 
    >> Varifocal lenses aren’t necessarily “bad”, as they can be less-complex for a given performance level. And auto focusing compensates for the change
    >> Worst of all… He doesn’t make it clear that perspective (the relative size of objects) has nothing whatsoever to do with a lens’s focal length. This error is repeated over and over in photography books.
    Nevertheless, this presentation is good in so many ways that just a bit of rewriting could make it perfect.

  2. I disagree with pretty much everything William Sommerwerck said in this response!. All of his statements are personal opinions and not fact, okay all OIS is IS, but not all IS is OIS is correct but the rest is just his personal opinions, for example, I can give you a dozen great sources that say Bokeh is pronounced Bow-KA not Bow Kay, another dozen sources that will argue this. Perspective does have a lot to do with focal length, just take a look at any of the GIF’s that are out there that show the difference that focal length has on a human face and you will see that the perspective changes quite a bit depending on the focal length, even thought the face size stays the same. So while I appreciate his comments, he needs to realize they are his opinion and not the final word on the matter.

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