ISO Experiment

[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

[Mike McCarty]

I wonder why it chose these settings on such a bright sunny day?

Jean,

Thank you for that question.

Given the lighting conditions you describe, the camera made a perfectly reasonable choice.

If you had taken the time to switch your ISO setting to 200 or 400, then taken a photograph of the same scene with the same light, you would not be able to tell the difference one little bit. The only difference would be that the camera would have chosen a progressively higher shutter speed.

And, if you had returned to that same scene in the late evening with much less available light, with your camera in auto ISO mode, it no doubt would have selected a much higher ISO.

When you, or your camera, select a higher ISO, it

[Jean Kelly]

Thanks Mike, sorry you lost your first post! I'm getting it! I played again today with different ISO settings with all the other settings done manually instead of auto. After I get more time on the computer I'll post my results. I found one small sentence in the instruction book about ISO settings on this camera. It states that settings higher than 50 will produce noise (increasing as the ISO is set higher). I don't know if that is for my model only (5400 Coolpix) or all Nikons in general of that vintage. Maybe yours is an "improved" version! I used the tripod today for all my playing around. I'm anxious to load them up but hubby gets the computer now, I get it later (we share).

Jean

[Mike McCarty]

I found one small sentence in the instruction book about ISO settings on this camera. It states that settings higher than 50 will produce noise (increasing as the ISO is set higher).

That seems very curious to me. Fifty is an extremely low ISO setting. When they say "noise," this is what I was calling "grainy." To suggest that there would be a reduction in quality at something just above 50 seems incredible to me. My Nikon D70 (a different, SLR type of camera) has 200 as it's lowest ISO setting. I'm pretty sure that your Nikon has a completely different type of chip but it's not that old. I would not have expected that kind of disclaimer.

It would really be interesting to see a similar type experiment that I've done above with a camera like yours. Even if it were only with two references like the 50 and then a 400 ISO. What is your highest ISO setting?

[Jean Kelly]

Hi Mike, my highest ISO setting is 400. I had a wiling model today, who was able to stay still for long periods of time, so I took about 100 pics at different settings. Here are three of them, same pose, same light, different ISO, all done manually. This was a really interesting experiment.

1st: ISO 400, shutter1/15, f-stop 5.7, there is a lot of "noise" in the colors of her fur. Random spots of violet, yellow etc.

2nd: ISO 100, shutter 1/4, f-stop 5.7, the random spots are disappearing, but still a little when I really zoom in. But not too bad.

3rd: ISO 50, shutter 1/2, f-stop 5.7. Clear as a bell no matter how far I zoom in.

These were all taken indoors with available light. Southern exposure but under an overhang. And all using the tripod.

Jean

After seeing this posted I guess I really have to crop closer to see the difference. I'll be back.

[Jean Kelly]

Okay, here are close crops of what I'm talking about. This is actually quite ridiculous, as I'd never need to see something this close! The first is at ISO 400, second at 50.

Jean

[Garth Herrick]

Dear Mike and Jean,

I think what we are finding in your comparisons between cameras, is that ISO 200 on the Nikon D70 (or my D100) yields a similar picture quality to ISO 50 on the Nikon Coolpix 5400, and along the same scale, ISO 1600 on the D70/D100 is about the equivalent picture noise quality as ISO 400 on the Coolpix. This has everything to do with the actual size of each pixel on the sensor. The sensor is much, much larger on the SLR type digital, and therefore each pixel is relatively larger too. When the pixels are larger they work cleaner and generate less noise at the equivalent ISO rating. This gives the Nikon D70/ D100 vastly increased sensitivity in low light without much sacrifice in quality. On the other hand, the Nikon Coolpix 5400 has the great advantage of being lightweight, handy and portable all day in a pocket, with no bulky long lenses knocking into everything. There is a good reason for liking each camera.

Garth

[Mike McCarty]

Jean and Garth,

This digital equipment is still pretty new to me and I'm learning a lot as we go. I think your analysis, Garth, is accurate. Nikon has all but told us so in the way they have configured the different ISO selections between the two cameras. One 50-400 the other 200-1600.

Having a better understanding of the individuals equipment can give us a better insight into how we might advise them through different situations.

In those ancient film days photography was film specific. No matter how clunky your equipment, you could shoot state of the art film. With digital, it's all equipment specific.

I've learned a great deal here.

[Jean Kelly]

Thank you both. Being the real novice here, I really feel I've gained the most from this experiment, and had fun too (and gotten some great flood pics)!

Jean