Learning this exposure thing

REFTRA

Back in a previous life, when I was in the Navy aboard a ship, we underwent periodic ship-wide training. This was a normal procedure following significant ship yard level updates. It was meant to refresh the crew with ship level systems and procedures. It was referred to as "REFTRA" for Refresher Training.

I woke up early this morning at about 2:30, let the dogs out to take care of things, but couldn't get back to sleep. Instead of just laying there, I decided to read, as I often do. I had my "Understanding Exposure" by Bryan Peterson book under the bed (not my normal library location, but I guess it's been there for a while) and grabbed it.

I remember the first time I read it, perhaps 6 months ago, when I was just starting my photography adventure. As I mentioned before, I had some experience with videography, but it was still a bit of learning curve to get a grasp of the relationship between shutter speed, aperture, and ISO. As I was re-reading the book this morning, it all seemed so obvious and hard to imagine someone wouldn't know what he was talking about.

I guess that means that some of the technical aspects of photograpy have become ingrained. I won't go so far as to say "second nature", because upon this second reading I was still picking things up.

ISO is my foundation

One statement Mr. Peterson makes that stuck a nerve with me is that higher ISO's result in less color saturation or contrast being recorded. I think I've noticed that but never made the connection.
I mainly use ISO 100, sometimes 200, even less do I use 400, and I've only tried any of the higher ISO's just because they're there and to see what they look like. But when I can, I use 100. I even wish I had a ISO setting of 50 available!

Because I don't do much at higher ISO's I probably haven't noticed the reduced color saturation or contrast as much. But it makes sense - and I would guess that shorter exposure times also do the same thing. It's similar to if you look at something (like a computer monitor), close your eyes, and then open and close them again as fast as you can. You'll see a quick flash of the object, and some level of color and contrast.

If you try it again but keeping your eyes open longer, you'll get more of a sense of the color and contrast. You might even see the image burned into your eyes while looking at your closed eyelids.
With less light sensitivity, that is, with a lower ISO, the sensor (film or digital) must be exposed to the subject longer, causing more saturation and contrast to be recorded proportionally.

In addition to increasing the noise level when the ISO setting is increased, it just makes sense to try to always use the lowsest ISO setting possible. I'm glad I read Mr. Peterson's statement again - it made me think about another level of ISO factoring in the exposure equation.

So while I rarely change off of my ISO of 100, if I do, it's the first thing that gets set, followed by the shutter speed and aperture. But I always aim for the lowest ISO setting I can get.

Here's a link to an explanation of ISO from Nikon: http://www.nikonusa.com/en/Learn-And-Explore/Article/g9mqnyb1/understanding-iso-sensitivity.html#!

Aperture

I didn't read much this morning on aperture settings. It was mentioned how there is a sweet spot (for a particular lens), and how f/22 can give you a good front to back sharpness in your image. I know from my prior reading that he does discuss focal length in more detail.

For the pictures I seem to take more of, primarily landscapes, I seem to fluctuate between what I think is my lens "sweet spot" of f/8 to f/11, up to the smallest aperture available such as f/22, depending on the zoom or focal length chosen.

I've never really tried shooting a test photo with the different aperture settings to see if the lens was sharper at one aperture vs. a different aperture. I should do that...

I have read about my lenses and it seems that different people report different values. I tend to think my sweet spots are in the f/8 to f/11 range because that's what seems to be very typical.

I have started trying to avoid the extreme ends of the aperture range, but it's easier to do at the small aperture than the large end. I don't have a lens that's bigger than f/5.6 (I want one, but, well, they're expensive!).

There are some images, though, that you want to shoot with a specific aperture setting, especially if you want a large aperture (e.g., f/5.6 ) to limit the depth of field, but it's bright daylight. In that case, it may be necessary to "cheat" by adding filters. On the other hand, if you want a small aperture but it's dark out, it may be necessary to bump up the ISO (I get nervous doing this, at least on my camera).

Shutter Speed

The shutter speed is the last thing I set, and on my camera, it's the easiest setting to change. For ISO or aperture settings I have to push an additional button. I have a hard time hitting the aperture button without looking at it for some reason, and that means pulling my eye away from the view finder (I rarely use the LCD for taking pictures, BTW). The ISO button is even worse - I have the programmable button normally accessed with your left hand on the front of the camera set up to control ISO. This is one of the disadvantages of the entry level camera - fewer dedicated buttons or controls.

I like taking the slower shutter speed images for most of what I do. I almost always am using my good, sturdy Manfrotto tripod so I don't even really think about the impact of shutter speed. Unless it's windy anyway. It's only when I'm shooting hand held that I think much about shutter speed. And, it's where I have problems.

My hands aren't very steady and never have been as far back as I can remember (and that's back to the 1970's at least). I really have to try to get shutter speeds at least as fast as the common rule of thumb - 1 over the focal length (e.g., if your focal length is at 200 mm, you should get a shutter speed of at least 1 / 200 of a second).

If I can't get that shutter speed with the ISO and aperture I am trying to use, my choices are to change one or the other of those settings or to risk a soft (blurry) picture. Sometimes you just have to take the risk, such as when it's a picture that is fleeting and may not be around if you start futzing with other settings.

The very bottom line

Again, the last thing I want to change is to go to a higher ISO, again, on my camera. I've seen pictures other people have taken with the D3200 at higher ISO settings and they don't seem to have much noise in them. Either I'm not doing something that they are or I have a bad D3200 or who knows what. At this point, though, I understand that I have issues with noise, and often even at ISO 100. But I also know my noise issues increase at anything above ISO 400.

I have started buying into the idea that more megapixels in the sensor is not always a good thing, and that with fewer but larger cells on the sensor, especially for darker shooting conditions, might be a good thing. If nothing else, it's a reason to try a full frame camera with fewer megapixels!