Normal vs Telephoto

Looking through my images, I found two other pictures showing difference in perspectives of images of the same subject with two different focal lengths.

This is a Satellite Dish Head.

I took these two pictures with the lens Canon EF 28-135mm f/3.5-5.6 IS USM on a Canon T1i.

This image is related to an earlier post on wide angle vs semi telephoto (which is actually normal). Here the difference is much more obvious since the background isn't just a wall.

If you ignore the fact that one is a bit overexposed and one is a bit underexposed, you can clearly see a huge difference in term of perspective.

There are several things that affect perspective, one of them is the sensor size. Both of these images were captured with the same camera, T1i, which has a crop size sensor. More precisely it's a APS-C Sensor that if I'm not mistaking has the dimensions of 22.3 x 14.9 mm. This means that if a full frame sensor size camera was used with the same lenses and captured the image in the exact same settings, The image would contain more of the surrounding. In other words, a crop sensor, gives you a cropped image of a full sensor's image.

Given that the sensor is the same in both pictures, the background is clearly seems closer to the subject in the 135 mm shot than in the 56 mm shot. This is due to the properties of light and lenses and how light from a source changes it's path while it goes through a lens depending on its distance from the lens.

I don't want to talk much about bokah and depth of field (DOF) for this image because, the aperture varied and that would make the discussion biased, since aperture plays an important role in depth of field and bokah levels.

In general, you want to use telephoto imaging to reduce the amount of background and foreground in the images since it will compress the horizon. This means telephoto is good for portraits. And normal focal length photography is good to capture a decent amount of the background  and a subject... for instance, portrait with background photography.

Again, when I started shooting i wondered how flash could affect images.

One circumstance in which Flash photography is important is when you take a picture Indoor and you can see Outdoors through a window. If you don't use flash, and use automatic settings, you can notice a problematic effect: either the indoor is too dark or the outside is too bright.

Of course you can take an HDR (high dynamic range) image that allows you to view both the outside and an inside, as us humans can see but... that is not always a realistic choice since it requires more than one shot and some preparation.

The easy solution is to turn on your flash and illuminate what's in the room to match the brightness of the outside world.

Now you have to notice one thing, if it's sunshine bright outside, your flash is probably not strong enough to compensate for day light, but this could work during not so shiny evenings.

Anyways, I took an interesting shot a few years ago of a glowing LED of a Christmas tree on a Window, and here's how it looks with and without flash.

Settings are:
With flash: focal length: 50 mm aperture: f/ 9.0 shutter speed: 1/200 s ISO 400
without flash: focal length: 55 mm aperture: f/ 7.1 shutter speed: 1/100 s ISO 100

I had my camera (Canon T1i) on P, which is Program mode. Which is pretty much automatic.

HOWEVER, what made the image have the right exposure was the Metering mode. It was set on Spot metering. And the middle (the spot) was on the LED. the LED was my reference point for the exposure which allowed the outside exposure to be quite similar in both images.

Anyways, i find it's an interesting comparison here are the images:

Wide Angle vs. Semi Telephoto

A few years ago, I started with photography as a hobby. I was still confused about how does the lens affects the image. Over time i learned that the lens you chose is much more important than the body you chose.

I discovered that lenses play a big role on perspective, among many other things that i wont discuss in this post. More precisely, the focal length you chose with your lens.

When i was practicing the techniques of photography, I tried to shoot the same subjects from different distances and different focal lengths in order to see what would be the difference.

I took two shots, one at 18 mm and one at 55 mm with the lens that came with my Canon T1i which is the 18-55 f/3.5-5.6. And now that I'm looking back at my pictures I decided to compare the two shots and make some notes on them. The differences aren't obvious because the choice of subject and background was not perfect for educational purposes but it's good enough.

Here are the main differences:

•  Background & Foreground visibility
• Depth of field
• Bokah level
• Horizon compression/stretching
• Distortion level

Here is the picture