Monday, September 27, 2010

Exercise 3 - Focus at different apertures

With this exercise I should find out, what will be the focus area at different apertures with focus set in the middle of the picture. Leaving in 10 minutes driving from Baltic sea, I decided to take some shots of the row of concrete stones on the sea shore. For all three shots focus has been preset at 7m. Here are the shots I finally got:

1. The widest aperture - f/3.5; shutter speed - 1/640s.
2. The middle aperture value - f/13; shutter speed - 1/60s.

3. The smallest aperture value - f/22; shutter speed - 1/20s.

The conclusion for these three shots is that the larger is the aperture the smaller is depth of field, the smaller area of the picture stays in focus. Depending on what you want to be in focus you may use wider or smaller apertures. E.g., when taking macro pictures it is good to highlight the object more and blur the background. In these cases the big aperture might be preferred. Also, the big aperture would compensate the faster shutter speed, which is crucial when taking picture of moving object (birds, animals, insects). In this way moving object will be sharp and background blurred.


Exercise 2 - Focus with a set aperture

For this exercise I have chosen my Roland keyboard. The sequence of keys is long enough to see the difference.
However, the constrain was that the super-zoom lens Tamron 18-250 is not a perfect option for taking pictures similar to macro. The keys were a bit too small, and to make it look nice, I had to adjust the angle (focal distance) a bit. The biggest aperture of my lens would be f/3.5 at focal distance 18mm. I was shooting at approximately 22-25mm and with maximum aperture f/4.2. Anyway, here are three pictures with focus on different parts of the object:

1. Aperture - F/4.2; Focus distance - 0.45m; shutter speed - 1/60s.

2. Aperture - F/4.2; Focus distance - 0.7m; shutter speed 1/50s.

3. Aperture - F/4.2; Focus distance - 1.1m; shutter speed - 1/50s.


  • On the first picture the focus is on the front side of the keyboard at focus distance 0.45m. Though the first three black keys are not in focus, as the shooting distance was a bit too close for this lens. 
  • On the second picture the focus has moved a bit further to 0.7m. There are now five black keys blurred, while keys on a longer distance are in focus. I think this shot is the best out of three, as it gives the whole view of the row and focus is evenly spread. 
  • On the third picture focus has moved even further from 0.7 to 1.1m. This has pulled the focus out of the keys to the button behind the keys. This makes 90% of the picture blurred and does not really look nice.

Friday, September 24, 2010

Exercise 1: Focal length

To be honest, I was a bit confused by the first exercise... I had to take three pictures: one at longest focal distance, the second at the shortest focal distance and the third at a standard focal distance. I did not have any problems with first two pictures. But I struggled with understanding, what means standard focal distance. After consulting with mu tutor I got the following shots:

The picture at 'standard' focal length was at 60mm:

Here are also the two other pictures:

At the smallest focal length of 18mm:

 And at the longest focal length of 250mm:

Project: Getting to know your camera

Looking through the first project and comparing it to my camera features, I found certain things that are useful to know. I was quite aware about the options of the camera, but decided to get into more technical details.

I know exactly now, what f-stop means and how it is calculated. Basically, f-stop is a focal ratio, which equals focal length divided by aperture diameter. This explained to me, why the bigger is F-number, the less light is getting through the aperture.

The full exposure step is a square root from 2. Most of modern cameras use 1/3EV, which comes together with ISO standard. I checked and it appeared the same for my Nikon D40. At least I know now, what this 1/3 EV means.

As for aperture diameter meaning. Keeping it simple, aperture determines, how many rays of light reach the sensor. With wider aperture object in front is in focus and background is blurred. This is a good thing to know, when taking macro pictures.

Shutter speed determines the time aperture is open.

So, basically there are two parameters that determine everything - the size of the 'hole' and the time 'hole' stays open to get the light. Depending on which parameter you change, the other parameter is being adjusted to another. In other words, you can get the same result either by changing the 'size of the hole' or 'the period, while hole stays open'.

I hope, I am not too confusing...

As regarding my camera Nikon D40 and lenses, the parameters I have learned now, are:

  • Exposure step = 1/3EV
  • Sensor size = 23,7 x 15,6, which equals to most modern cameras ratio 4:3
  • Tamron lens: f-number = 3.5 till 6.3; Focal length 18 - 250 mm, which gives angle view range from 100 to 10 degrees.
  • Tokina lens: f-number = 4; Focal length 12 - 24 mm, which gives angle  view range about 118 to 84 degrees. 
Considering sensor size, the angles of both my lenses should be multiplied by 1.5 (crop factor), which will give the actual angle that lenses cover.


Wednesday, September 22, 2010

Equipment overview

Before getting further to tasks, it would probably be worth to list the equipment that I am going to use for my tasks. When moving further, I would also like to find out, whether what I have is enough for taking good shots and whether it is sufficient for myself. If not, then I am looking forward to find out, what else I need to be happy with my shots. At the moment I am a happy owner of the following photography stuff:

1. Camera Nikon D40
I am pretty sure that this camera is a good budget choice for a person like me, who is just starting with photography as a hobby. However, there are at least two constrains with this camera: 1) It does not have a built-in auto focus motor, which will define the range of lenses for some extend 2) It does not have a port for cable remote control port. Of course, it has infra red port and it is possible to use remote control without cable, but I had a couple of situations, where I wished I had a cable for longer shutter speeds to avoid camera shaking. Anyway, I still like my D40 and we will see how he will manage with all the assignments of this course.

2. Lens Tamron AF18-250 F3.5-6.3 DiII with built-in motor.
This is again a budget version of superzoom lens. I like it, because it works for nearly all types of pictures I want to take. However, again, there are some minuses that I have notices: 1) a bit slow auto-focus; 2) vignetting at the longest zoom, especially if I have polarizing filter on it.

3. Lens Tokina 12-24mm F4.
This lens I bought especially for landscape photography, as it gives slightly wider angle than my Tamron lens. At the moment I can't think of any problem that I had with lens. Again, good budget lens.

4. Tripod Vanguard with level.
I am quite happy with it, as it is robust and useful thing to have. To add some criticism, I would say that the head of the tripod could be a bit better, I find it difficult at times to set horizon line right with it.

5. Filters: I am using Hoya Polarizing and simple glass filter when taking pictures with Tamron. I also have Cokin set of gradual density filters.
I am absolutely happy with all of them. I hope to get more knowledge about how to use grad filters while doing this course.

6. As for post processing I have just installed Photoshop on my MacBook Pro. This is area where I know absolutely nothing. I have not tried to add some post-processing to my pictures up until now. I would be happy to start doing this.


Joining Open College of The Arts

I tried photography as a hobby quite a long time ago. The further I went with my hobby the more it seemed  that photography is an endless field for development and creativity. At some stage I realized that I need to develop my skills in a more structured way. When I accidentally read an advertising in DSLR Photography magazine about opportunities at Open College of the Arts, I thought that it could be a perfect opportunity for me. So, this is my first course within OCA and my first course of photography with professional photographer. 

In one week after joining the course I received the materials by post. This might sound stupid, but I was absolutely delighted by the soft red paper that was covering the materials inside the package! Besides course materials folder and different user guides, there was a nice notebook for learning log and a photography book that I find rather interesting and hope that I will have some time to read it and share some ideas that I will find most exciting there.

So, let's see, what I have here... I have my blog spot ready, I received all materials, I got in contact with my tutor, I have even paid my bill for the course!...It seems that it is time to start working NOW. My first deadline for the first assignment is 16th of November, and there is plenty to do before submitting the assignment. I wish myself good luck!