My second exercise today was also about focal lengths but this time the subject in the picture should remain same size. I first took a picture of a monument with my lens zoomed to 85mm. I then zoomed the lens to it’s widest setting which is 24mm. Then I walked straight towards the monument until the monument appeared same size as with 85mm.
Compared to the earlier exercise, this time the perspective changes dramatically. I placed the top right corner of the monument in the same position in the picture so you can really see the effect of using different focal length with different distance to the subject. Note that the distance is the key this time (see my earlier post). (more…)
Posts Tagged ‘focal length’
Exercise: Focal lengths and different viewpoints
Exercise: Focal lengths
This exercise is to appreciate the effect of different focal lengths as to know which is the amount of view of different lenses. The point is, I believe, to understand that focal length only set the angle of view. This mean that if you magnify a part of image taken with a wide angle lens (short focal length) and then compare it to same image taken with a telephoto lens (long focal length), all the relationship between different objects in the scene remain the same. I will prove this in the end of this post.
One should also note that I use Nikon D700 camera body which is so called Full Frame (FF-body). This means that the sensor in this camera body is the same size as 35mm film camera film frame (24 x 36mm). The focal length of lenses is expressed in mm. If a digital camera sensor is smaller than FF sensor it records smaller area of the view with same lens as FF camera body. This difference is called crop factor. For example Nikon APS-C (Nikon DX) camera bodies have a crop factor of 1.5. So, on a DX camera, a lens of 100mm focal length gives the same amount of view as a lens of 150mm of focal length on an FF camera. (more…)
Project: Getting to know my camera
At first glance the start of this course looked very simple. But even the first exercise did reveal some new information to me. Even though I thought that, I knew my camera. Well, I have read my camera manual and I have learned the f stops, shutter speed etc. a long time ago. My first thought was that these first exercises are quick and easy to do and they mostly help me to get along with my learning log.
The first exercise was about the lens and focal length. This was something that I had never paid too much attention before. On the 35mm film or ‘full-frame’ digital SLR’s the so called standard focal length is generally accepted to be 50mm. The standard focal length varies depending on the sensor size (film size). My other camera, Panasonic GF-1 is a Four Thirds system and the standard focal length on it is around 20mm to 25mm. (more…)