Comments on: The Aperture is Forgotten

By: Kevin H. Stecyk

Kevin H. Stecyk — Sat, 04 Jun 2011 16:45:27 +0000

I enjoyed your article. I had never thought to relate distances to ƒ stops on lenses. Once I read your well written article, it made perfect sense.

I did notice one small error.

>>In the old film days, we’d look at our lenses and always understand that the difference between F/2.8 and F/4 is one stop of more light (50-percent brighter) in one direction and 50-percent less light in another direction (darker).

When you increase an ƒ stop, you double the light. And when you decrease an ƒ stop, you halve the light.

So going from 2.0 to 2.8 is doubling the light. And then going to 4.0 is a double again. Thus, going from 2.0 to 4.0 quadruples the light. Going from 4.0 to 2.8 reduces light by half. And going to 2.0 is half again. So, going from 4.0 to 2.0 reduces your light by three-quarters, leaving only one quarter remaining. I know you know this stuff better than I do. However, it might be helpful to others.

Your text should be written as:

::In the old film days, we’d look at our lenses and always understand that the difference between F/2.8 and F/4 is one stop of more light (100-percent brighter) in one direction and 50-percent less light in another direction (darker).

If others find this confusing, think of money. If you have $0.50 and you double it, what do you have? A $1.00, right? And, if you reduce a dollar by half, what do you have? $0.50, right? It’s the same idea.

Thanks again for the article!

By: olivier borgognon

olivier borgognon — Wed, 02 Dec 2009 12:23:19 +0000

I totally agree on that loss, a great shame, most of the people using point & shoot and then some p&s allowing more and more “parametering” with some manual modes, but something like hybrid stuff… doesn’t really make sense, with optical and digital zooming making things even worse.

Thanks for reminder about the inverse square law, always good to get back to the basics.

I don’t mind the information being on screen through the lense viewer, but i agree that i would appreciate being able to change it on the lense or on the “wheel”. albeit the changing of this aperture was mechanical before thus every “click” was physically opening and closing the shutter, not it’s all electronically controled it is quite different.

By: Carlos Moreno

Carlos Moreno — Tue, 20 Oct 2009 12:58:39 +0000

I throughly miss the process by which we used to take pictures with a film camera. Turning the the aperture ring and thumbing the shutter speed dial are such physical components of photography that I loved and now miss. I remember occasionally finding my reflexes wanting to look for a knob or dial when I first started using the newer digital cameras. I still enjoy turning off the auto focus now and then and using the manual focus ring with certain lenses. However, it’s with a bittersweet pill that I find that I cannot easily read an aperture ring without the aid of reading glasses. The LCD screens are easier to read than the tiny numbers on an aperture dial.

By: Ian Worthington

Ian Worthington — Sat, 12 Sep 2009 23:09:52 +0000

And don’t forget the loss o the DoF scale that accompanied it. I miss that *more*.

By: DantePasquale

DantePasquale — Thu, 10 Sep 2009 01:26:44 +0000

Hi Mr. Gomez,

Thanks for pointing this out. It was one of the most difficult things of switching from my “analog” camera to digital (also, the delay when I press the shutter has taken some getting used to too). Is there a reason why some digitals have stuck to the “inverse square” values and others have those weird values? very confusing when jumping from camera to camera. Ciao, Danté