Saturday, April 23, 2011

Fast Lenses -- How Do You Use Yours?

Mike Johnston has written an interesting article on f1.4 lenses.  I agree with most of what he says, especially that using fast lenses at their maximum aperture at all times is just silly.

I like fast lenses because they give me options to shoot at low light when using slower lenses is not possible to get the pictures I want. Sure, you can crank up the ISO to compensate, but as the light dims, there is only so much headroom you can get from ISO.  We all know that as the ISO increases, the image quality decreases.  Fast lenses allows me to shoot at lower ISO and still maintain sharpness with fast enough shutter speed.

Fast lenses are also made better, especially with modern lenses.  This was not really an issue in the past, when lenses were all made with longevity in mind.  If you compare an FL 50mm f1.8 and the FL 50mm f1.4, you will notice that they were practically made identically, except the optics, but you can already tell there is a difference between a New FD 50mm f1.8 and the New FD 50mm f1.2.  

Freedom of depth of field control is another benefit for fast lenses.  For many people, this is the major reason to buy fast lenses, but like everything else, there are situations where thin depth of field is not appropriate, and there are situations where creative use of thin depth of field can make your pictures stand out from the norm.

If you read my previous posts, you will see many pictures with very thin depth of field.  I like to isolate my main subject from background.  Looking at the pictures with very thin depth of field immediately tells you where the main subject of interest is.  The most interesting bokeh is usually at the widest aperture, and unfortunately, I am an incurable bokeh addict.  That's why I have so many pictures with thin depth of field.

The question comes down to this:  does it matter how you use your lens?  Absolutely not!  A lens is a creative tool.  If your creative vision is best expressed at f32 with an f1.4 lens, who's to say that's wrong?  The softness from diffraction limit combined with huge depth of field may create interesting pictures.  Of course you would argue why not just buy a cheap slow lens, but what if you want to shoot at f1.4 the next minute?  See, fast lenses give you a choice that a slow lens can't.

I am addicted to fast lenses.  It really is an expensive and unhealthy addiction, but I enjoy it nonetheless.  Some like fast cars, and I like fast lenses, and I use them anyway I like.

Hands -- NEX-5 & JML 50mm f0.95 @ f0.95. Click to see larger.


    1. I agree I shoot it the widest open for most of the shots unless I want to have multiple subjects to be in focus or the whole subject instead of partial I would stop it down. Would buy lens cause of able to be wide open and if I want everything in focus I would buy a wide angle lens with a short infinity.

    2. I love a thin DOF and really enjoy shooting in that style. I did a quick test with a couple Rokkors of mine, a PF 1.4 and a PG 1.2, and when both shot at 1.4 the PG 1.2 ultimately lets in more light. +1 for faster lenses. Another thing I love about 1.2 lenses is that you can shoot stopped down at 1.4, which for my 1.2 lenses makes them sharper than my 1.4 lenses wide open. 1.4 is still a nice thin DOF for us bokeh junkies too :)

    3. @Chung Dha Lam: Yup. One should use the lens however they want.

      @natebarnz: A fast lens has better image quality when stopped down to the same aperture as the slower lens' maximum aperture.