Friday, January 31, 2014

Camera settings and their actual effect.

A friend just bought his first dSLR and immediately started taking pictures to get to know it, which is the best thing to do once you get one. Don't ogle over it; just go out and start taking pictures, while noticing what changes in your photos when you change a setting at a time.

During his first tries though the results didn't go along with the mental images he had. And I'm guessing here that the manual may be at fault a bit. Most often the manual says that you should try and expose the image correctly with the exposure meter. Yes, you should, even the cheapest of the dSLRs now have great sensors and can forgive a step up or down. (A bit underexposed or over exposed. If the circumstances are such that you can't get a perfect exposure, you can fix it later in lightroom or photoshop. Though that should be the last resort...)

Aperture for emphasis.
Manuals most of the time say that the aperture setting is for changing the lens's iris, allow more or less light in and that will make the depth of field shallow or deep. Now i know you'll yell "semantics!" and you'll be right i guess, but it should be the other way around, that the aperture setting allows you isolate a subject or bring everything in focus. I'm putting it like that to make it easier to realize just by reading it from the first time, that if you want to make a single thing stand out, that's what you'll use, instead that "it changes the amount of light through the lens and in doing so makes stuff blurry or not." People tend to think of non-sharp photos when you say blurry, instead of thinking isolated subjects with bokeh.

Shutter speed as a time function.
Same thing with the shutter. It says to keep a fast shutter to avoid shakiness in your photos. Well yeah, if the results came out shaky and you don't have Image Stabilization, tripod or steady hands, using a faster shutter will help with that. But don't think of the shutter as the thing to make your images ... not shaken. Grip the camera firmly, have the shutter button semi pressed and ready to just press it just a tad more to release the shutter and you can do well with a slow shutter speed. You should think the shutter speed as a way to express time instead, add movement and life in a still photograph. There is this thing that people say; that you should keep your shutter speed at, or above the lens's focal length, meaning that you should have 1/50 for a 50mm lens. Let me tell you that you can go handheld a lot lower than that with just a tiny bit of practice and no IS. If you want to capture a car moving fast, you can use lets say 1/200 and get a steady car, with the wheels blurry from spinning, and the trees blurry from you tracking the car. But do that with a human walking and it's just a frozen thing. May as well be standing still. Go for a slower shutter speed, one that will get your subject's limbs just starting to go blurry from movement and then use the aperture to cut down light. Want to isolate the subject as well? Use a lower ISO setting. Don't have a lower ISO setting? Well at that point you'll need to get an ND filter to cut down light I'm afraid. But the point is that there's still a way.

So don't think the settings as the way to get your exposure meter at the center. Instead think of what you want to show in the picture and use the tools for that, there lots of times you'd want to have motion blur.

Tuesday, January 21, 2014

Noobie trap in Unity. (Or "How time flies". Or "Time.deltaTime")

So i wanted to make a small timer in the upper left corner of my small game.
Extremely easy; you just have a variable storing float values and add Time.deltaTime on every frame to it (deltaTime is the time it takes to render a frame.)
Thing is, if you are using something other than "1" in time scale or playing with timeScale to do some slow motion effects, your timer will get out of sync with the real time that has passed. If the timer is to trigger an event in game to happen, no biggie.
If it's for stage scoring or leaderboards though, then the timer needs to be in sync.
So just take into account timeScale. Just divide Time.deltaTime by timeScale to always keep the timer counting in the same speed. (i.e. real speed, the same speed that a wall clock does).