Light Getting Low? Before Cranking Up The ISO Instead Of Using A Tripod There Be Something You Haven’t Considered

I almost never do this but this is the same image that I included in my last post but with a
completely different editing treatment.  You can see the other image here.  I thought this scene
could be interpreted in a number of interesting ways.  Do you have a preference?  (click to enlarge)

The light is fading fast.  You want to continue to photograph but the light is such that either you need to get your tripod out or significantly raise the ISO in your camera and continue to handhold your images, relying on the camera's image stabilization.  What is the better course of action?

Typically, and I'll include myself in this, with the help of advanced in-body-image-stabilization (IBIS) or lens-based image stabilization (IS) or the combination of both synchronized, most of us would choose to just raise the ISO and continue to photograph.  Of course, we know that more digital noise will be generated at high ISOs but, in the back of our minds, we also know we have the ability to reduce or eliminate that pesky digital noise in an unprecedented manner using Lightroom's new AI noise reduction, Topaz's Photo AI or DeNoise AI, DXO's PureRaw 3 or other noise reducing programs that use machine learning.  After all, with those image stabilization features, we can negate camera shake and with the advanced noise reduction software, we can now take care of the noise, why would we bother to lug around a tripod, set it up, move it, adjust it, move it again, etc.  Make sense?  Many of us would do just that.  As I mentioned, including me.

However, there may be something of which you are not aware or you might know it but don't think about.  That something is that anytime you raise your camera's ISO, your dynamic range is reduced.  Yep.  That's a fact.  In fact, typically around ISO 3200 you have about half the dynamic range available to you as you would at your camera's base ISO.  (See the charts below that I constructed from Bill Claff's site, wwwphotonstophotos.com.  My thanks to Mr. Claff for all the work he does for us and posts on his website.)

I have included in the below charts the major popular brands of cameras and three or so of the popular current cameras in each brand.  In every camera, the higher you raise your ISO the less dynamic range you have available to you.  In the last chart, I included at least one camera from each of the three popular sensor formats—medium format, so-called full frame, APS-C and Micro 4/3 so you can see a comparison of dynamic range versus sensor size.

Another interesting observation from the charts is that once you start raising the ISO, there appears to be change in dynamic range between camera brands/models as well as those sensor formats.  Only at base ISO do we see maximum dynamic range.  One more observation, at least in the cameras shown in these charts.  We've always been told that "Base ISO" gives you the best image quality and if we set our ISOs below "Base ISO" we lose dynamic range.  These charts show that any loss is negligible.  Just FYI.  I've used 'extended low' ISOs for years knowing that I really am losing nothing.

So...maybe the better answer to the above scenario is to take that tripod, get it out when appropriate, maximize your dynamic range and keep your digital noise to a minimum or to zero instead of being lazy (I'm calling myself that, not you) and relying on the camera's technology to squeak by with a decent image.  

Photonstophotos.com seems to be the 'go-to' source for looking at our camera models and seeing what noise and dynamic range are as compared to other models.  Here are the charts I put together from that site for education and illustration.  Again, my thanks to Bill Claff for doing the work in calculating these numbers.  Also, just an interesting point, have you noticed that Claff's calculations for noise and dynamic range vary quite a bit from DXOMark.com's numbers?  I don't know why but I suspect they each use a different method in their calculations.

Here are the dynamic range versus ISO graphs for three current highly regarded Canon cameras.

This graph shows the dynamic range of three current Fujifilm cameras.  Note how much more 
dynamic range exists with a medium format sensor.

This graph shows how dynamic range changes as you raise ISO in three current Nikon cameras.

Here is a graph showing dynamic range versus ISO in the OM-1 and two previous Olympus cameras.

Here are three current Sony cameras.

Here are the differences in dynamic range in some current popular cameras.  These graphs
represent medium format, so-called full frame, APS-C and Micro4/3 sensors.  There is less
difference than we may suspect, especially as you raise the ISO.

I would encourage you to go to Bill Claff's site to directly read the information he includes with his calculations.  I think it is important to understand these graphs in context.

I hope this information is helpful to you.  We all enjoy making technically excellent images and technique is quite important to achieving that goal.

Join me over at my website, https://www.dennismook.com.  

Thanks for looking. Enjoy!  

Dennis A. Mook  

All content on this blog is © 2013-2023 Dennis A. Mook. All Rights Reserved. Feel free to point to this blog from your website with full attribution. Permission may be granted for commercial use. Please contact Mr. Mook to discuss permission to reproduce the blog posts and/or images.