Mike McCarty

We’ve been talking about the ISO setting on our cameras lately, what we used to refer to as film speed with film cameras. If you shoot only in artificial light, or outdoors in sunlight, you could set your camera on a low ISO and fugetaboutit. But, if you choose to operate indoors in available light then a greater understanding of how ISO affects your results may be in order.

One thing I really like about my new digital camera (Nikon D70) is that I can experiment all I want and it doesn’t cost me a dime, and, I don’t even have to leave the house. So I thought I’d try and investigate what the variance would be between ISO 200 (the lowest setting on my camera) and ISO 800 (the highest number worth considering for this work).

I always felt comfortable with good quality color film at 400 speed (ISO), but have heard that the good digital cameras may produce an equally acceptable quality at 800 ISO. The term “sensitivity” is more apt than “film speed” for digital cameras but as best I can tell the theory is the same.

As with most things in life there are trade offs to contend with. We want the best possible image, dense and crisp, but we also want to shoot in low light conditions. These two factors are at constant odds. Somewhere between functionality and quality we have to strike the balance.

For me it was always that if the light was so scant that I could not operate with 400 speed film then I was not going to proceed. I new that an 8x10 (the larger the image the worse it gets) image shot at 800 ISO would not yield the type of quality image that I desire. The difference was that noticeable. The term used to describe the deficiency was/is “grainy.”

I shot the following at JPEG, Fine, Large. This produced an image of 3008x2000 pixels and about 1 mb each. The cropped examples (first the 200 ISO, then the 800) were cropped to the maximum for forum use at 400x600. So the images should be as good as you can get for forum use.

The first two images are the full images shot. The first was shot at 200 ISO setting and the camera produced an exposure of -- shutter speed 50th of a second at 4.5 aperture (f stop). The second is at 800 ISO and produced an exposure of -- shutter speed 200th of a second at 4.5.

The salient point above is the difference in shutter speed from a 50th of a second, almost the minimum for hand held operation and subject movement, to 200th of a second, comfortable for any use. The question is -- did our increase in functionality, 50 to 200, produce a reduction in quality such that we would deem it unacceptable.

Attached Images

       

__________________
Mike McCarty

Mike McCarty

From what I can tell there is a slight degradation but this shows up most noticeably in the background. This of course is a blurred out of focus element anyway. I would like to have the two prints side by side for a comparison.

The first image was the 200 ISO, the second the 800 ISO and the combined shows the 200 on the right.

Attached Images

     

__________________
Mike McCarty

Jeremiah White

I used to be more concerned about excess noise at higher ISO settings but now I really don't anymore. I recently purchased a Sony F828 and at higher ISO settings it is noisy but this program called Noise Ninja really cleans things up well without losing quality in the image like filters in photoshop and others do. It's pretty fun to play around with too because of how clean it makes things. It takes a bit of playing around with to get used to it but once you get a good grip on how to use it, it becomes a great tool in your digital photo software arsenal.

The link for that program is http://www.picturecode.com

__________________
JJWPortraits.com

Chris Saper

Mike,

I can't say that I see any real problem with the images - at either ISO. It is interesting to see the extreme close-ups, since the snapdragons are well beyond actual size, and you wouldn't really ever need that for a human.

__________________
www.ChrisSaper.com

Michele Rushworth

Interesting demo. I can't see anything about the 800 ISO images that would be unpaintable. Time to go try this out with my own camera.

Also, thanks for choosing snapdragons for this demonstration. There is a large floral arrangement in the portrait I'm working on now and it has lots of snapdragons in soft, even lighting, much like you show here. I can use these photos as extra reference! (Of course, I'll need you to sign here, here, and here, to give me permission to violate your copyright. But then again, I'm hoping you'll never find out.)

__________________
Michele Rushworth
www.michelerushworth.com
mdrushworth@comcast.net

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.

Attached Images

 

__________________
Mike McCarty

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.

Attached Images

       

__________________
Mike McCarty

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.

Attached Images

       

__________________
Mike McCarty

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.

__________________
Mike McCarty

Michele Rushworth

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

__________________
Michele Rushworth
www.michelerushworth.com
mdrushworth@comcast.net