bn 2009

room 206

Shot 2 - Object Buffer Pass

I was ironing, and then i just accidently took a picture of the blanket i use to iron.

Objects in motion

For this first part of the experiment I set my camera to a focal length (f) of 50mm and an aperture of f/5.6 (N = 5.6). The distance (U) between the camera and the object was 615mm. The last missing variable in the Depth of Field (DoF) formula ((2CNU^2)/f^2) is C - the Circle of Confusion.

Computing C as follows:

Let's say: everything smaller than 1.5 blur counts as in focus.

The picture's size is 1176 x 1665 pixels. So the diagonal of it is: sqrt(1176^2 + 1665^2) = 2038 pixels.

The APS-C Sensor of my camera has a size of 15.8 x 23.6mm and thus a diagonal of 28.4 mm.

So I compute C = 1.5 / 2038 * 28.4 = 0.0209.

Now I can compute the theoretically expected DoF:

DoF = ((2*0.0209*5.6*615^2)/50^2) = 35.41mm. Since the ruler is at an angle of 45°, this result hast to be modified by multiplying by sqrt(2): DoF = 35.41*sqrt(2) = 50,08mm.

Looking at the picture, I'd consider the numbers between 140mm and 90mm in focus (DoF = 50mm). So the experimental result fits the theoretical result very well.

nikkormat+nikkor 80mm f2+Ilford iso 100

at f4, 1/60

View On Black

Yes, I'm a chain smoker :P

(Taken with my "quality" cell phone camera)

Just a random shot. :P

On the left, dead, useless plug. On the right, lively, scooter-powering

plug. Know the difference! It finally occurred to me the check the plug

after my scoot wouldn't start for the third or fourth time in a week. I

changed it in the corner of 18th and Washington. A man asked me for a

cigarette while I was doing so.

(Sent from my phone.)

One of my favorite past times.

Objects

12/365

Object 365

Familiar kitchen objects, viewed from an unfamiliar, close up, perspective: a Starbar. Not exclusively found in kitchens, but it was there on this occasion.