Monday, July 02, 2012

Photography Quiz (F-stop blues!)

((Apologizing in advance for the weird formatting, I've previewed this post a few times and it looks weird every time, but I am tired and tired of hassling with it...))

More fun with the camera this evening, trying to figure out this whole F-stop and depth of field thing. I tried mightly this weekend, at one of the largest ultimate frisbee tournaments in the world, to capture some of the action on the field, but when I took a look at the pictures afterwards, nearly every shot was blurry.

I was a little frustrated, because I tried just about everything out at the fields to ensure at least a few of my photos would turn out nice. I tried automatic setting, manual setting, single shot, burst shot, and I even tried burst shot while manually changing the focus of the camera as the burst was shooting... but nothing I did made any difference to my blurry photos! If you couldn't tell already, I'm a bit of a newbie...

Last night I did some reading in the camera manual and found that what I needed to be changing is the F-stop. For some reason the automatic setting on the camera reverts to usually the smallest F-stop setting, because at that level, there is less light needed for optimal shooting... the problem lies in the fact that a small F-stop means a very narrow focus range, which means someone's elbow might be in focus but the rest of their body isn't... which makes for a lot of blurry photos!

So why not shoot with a high F-stop all the time to get everything in focus? Well, a lot more light is needed. I'm learning various tricks to get more light, but you always have to give something up to get more light. The longer you expose the photo, the more light you get, but the harder it is to keep the camera still. The higher ISO you use, the more light you get, but the picture gets grainier.

Here are a couple of examples, and then a quiz!

Here are the specs for the above two photos:

top(left?): f-stop 5.6; exposure: 1/6sec; iso: 400
bottom(right?): f-stop 20; exp: 2sec; iso: 400

The bottom picture is a whole lot crisper, and it has to do with the f-stop being much larger, but you see the camera shutter was open for two whole seconds, which means I HAD to have a tripod for this shot or my hands would have shaken the camera into drunken blurriness! If you think (like I thought) that the top photo might have just been blurry, take a look at the difference between the line on the right with "Bill Clinton" and compare the blurriness of that text to the text in the bottom left or top right of the page--THIS is what was happening to my photos at the frisbee tournament--a little bit of focus, but usually not on the action, and the rest of the shot was blurry, which wasn't what I was going for!

Here is another example.

Tilted the page back a bit more in these shots to show the loss/gain of focus--here are the specs:

top: f/5.6; 1/5sec; iso: 400
bottom: f/29; exp: 5secs; iso: 400

Again, in the top photo there is a fine band of somewhat focused text. You have to look close near the Bill Clinton line and compare it to the text at the very top and bottom of the page. The bottom picture is much more in focus throughout, even though the ISO is the same, but you see an even bigger f-stop and now a five-second exposure, 30x the length of exposure of the top photo! Again, thank you tripod.

Now for the quiz! Let's see if anyone still reads this blog and has any interest in photography...

I took seven photos of my computer screen as I began typing this post. The photo was from about six feet away, and zoomed in on the text with a white background to help with light issues--this time I took the photos hand-held, which is a very big factor in the blurriness of photos (which I realize I didn't get into much in this post, but it does help answer this quiz correctly!). I will give you the specs of the seven shots and you tell me which photo you think came out the most in focus, also, which photo came out least in focus--only from reading the specs. I will post the photos Friday!

1--f/45 exp: 1/6sec iso 1600
2--f/45 exp: 1/4sec iso 1600
3--f/29 exp: 1/10sec iso 1600
4--f/5.6 exp: 1/80sec iso 400
5--f/29 exp: 1/5sec iso 800
6--f/20 exp: 1/10sec iso 800
7--f/20 exp: 1/20sec iso 1600

Good luck!



Blogger GeneGinny said...

Too many variables for me!

9:03 AM  

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