ISO Experiment

[Mike McCarty]

Michele,

Take them, use them, abuse them. Here's another one if you please. I'd even send you a high res. if you want.

Jeremiah,

I've not heard of such a thing. No surprise there though.

Chris,

I was a little surprised at how well the 800 ISO held up. When you think that these are pretty radical closeups. I still think I'll draw the line at 400 ISO, but it's nice to know that I have the 800 in the bag in certain extreme circumstances.

[Mike McCarty]

I operate under the principle that anything worth doing is worth over doing. Kind of like the Rocky movies. I had to take this experiment to the extreme.

My camera has a range of ISO settings from 200 to 1600. I re-shot the above using the following ISO settings. The shutter speed was correspondingly selected by the camera in portrait mode, all at aperture 4.5:



ISO 200 shutter speed 100
ISO 400 shutter speed 200
ISO 1250 shutter speed 800
ISO 1600 shutter speed 1000

The first is the full image shot at 1600 ISO. The next three are closeups 400, 1250, and 1600 ISO.

[Mike McCarty]

The first two images are crops from ISO 400 then 1600.

The next two are cropped further (from the bottom right corner of the previous two) from the ISO 400 then 1600.

[Mike McCarty]

This seems remarkable to me. It suggests that from film to digital, in this regard, it's not apples and apples. Someone just said "Da."

I think it's something like this -- if you think of film as in pixels, it only has it's finite best. So this fixed pixel best, was put in combination with a fixed sensitivity (ISO), to create it's best fixed quality. Sombody stop me.

Digitalia, on the other hand, at it's high end settings surpasses the fixed pixel best of film, and maybe by a long shot. If this is true, then you have to re-shuffle your matrix of the limitations of high end ISO settings.

Or, and what is more likely, I am completely full of crap and yet, still walk around without a keeper.

[Michele Rushworth]

There is an amazingly small amount of difference between the closeups of 400 ISO and 1600 ISO shots. Who'd have thought!

[Mike McCarty]

The other thing that tells me the apple cart has changed is that with film, the lowest color print film ISO was 100, then 200, 400 and 800. With slide film I think it went to 25 or 50 ISO. With my camera, Nikon has opted to have 200 as the bottom end.

I'm sure that they have thought about this a lot, and maybe even run some tests. The only thing I can figure is that they must have concluded that 200 digital, is so much better than 100 film, that there's no reason to take it down any further.

I'm tempted to print a couple of these examples out in 8x10 format. Although you would think that if it was going to fall apart it would be apparent here.

Actually, my first reason for doing this exercise was to demonstrate how different ISO settings affect shutter speed. Notice the above settings and how the shutter speed increased when the ISO increased. Higher shutter speeds can be your friend, lower shutter speeds can make you vulnerable to camera shake and subject movement, thus causing blurry images.

I've exhausted myself on this matter, I should nap.

[Jean Kelly]

Hi Mike, I hope you are feeling more rested. I've not been able to photograph people lately due to the increasingly depressive stormy weather, flooding all over and gloomy skies. I've got to get the chroma 50 lights installed upstairs! I did try one experiment yesterday though. We took off on one of our "daytrips" to look at some of the area flooding, and for me to photgraph it. The Baraboo River in my hometown is about 4' over flood stage, so that's where we headed. I set my camera for automatic ISO, just to see what would happen, it was our first day of sunshine in a week with no rain forcast till later in the day. ALL of the pics came back with an ISO of 50! I'm confused but refuse to obsess on it. Next sunny day, I'll try setting the ISO at 200 and 400 manually.

This photo was taken on all automatic settings. Shutter speed 1/144, f-stop 4.4, ISO 50, file size fine. I wonder why it chose these settings on such a bright sunny day? I used to hop rocks in this river, can't even find a rock in the water now.

Jean