Photo Tips and Quips: Managing Your Depth

When considering how to make an image one that is better than average depth of field is one of the most important things to think about. Depth of field is essentially how much of what you are looking at is sharp and how much is blurred out. Depth of focus is controlled by setting your cameras aperture. If you are used to shooting your camera in auto mode but are not happy with average results maybe is time to take the next step and move on to Aperture Priority. All SLR cameras have this option and some point and shoot models allow you to. You might consider changing your camera settings to manual, but fair warning, if you don’t understand the shutter speed and ISO then a switch to manual is going to require you to juggle all three (aperture, shutter speed and ISO) at the same time.

Just about everyone has heard of a pin hole camera, a card board box with a small pin hole in it, it is that tiny little hole that allows light in to hit the film and expose the film. That tiny little hole is considered a small aperture because it is not very open and allows light in very slowly. The result of this small aperture is that everything that is in the image is sharp from the front of the image to the back (it has a very wide depth of field). Conversely if you use a camera lens with a large  aperture  you let a lot of light in, but if you are letting a lot of light in you can’t expose the film or sensor for very long. If you are in aperture priority the camera will set the shutter speed fast so that your image will not be overexposed.   The result is the light from things more distant from where your camera is focused will be blurry. This is because the light has not had enough time to reflect off of more distant points in your composition and get back to the sensor in time to have any detail. (A simplistic explanation). So If you want to understand all this garbleygoo I have been talking about here do this little exercise.

1. Set your camera on AV. You might need your manual to be able to know how to change the aperture.

2. Put a lens on your camera that says it is somewhere around 70mm to 100mm. Set it on the largest focal length possible (Zoom in as much as you can)

3. Ask someone to model for you. Stand them about ten feet in front of some trees or bushes or something that has some definition. Then you get back far enough from them that you can fit at least half there body in your viewfinder.

4. Find your camera’s largest aperture. It will probably be 3. something or possibly 4 or 5. something. Take a picture. If you are using digital you should be able to see that the background is blurred out.

5. Now change that same number until it says 16. Take the picture again from the same place. Now whatever was behind your model should now be in focus.

If it worked you have just taken your first steps into more advanced photography. If it didn’t set your ISO to around 400 and try it again. If it still doesn’t work email me at info@kentonrowephotography.com and I will see if I can help you figure out what is going on. Good luck, and let me know how it goes.

This image has a very wide depth of field. Everything from the house to the turtle is sharp.

This has a very shallow depth of focus.  Auston’s eyes are sharp and his ears are soft.

Why Canon?

I wish I had a dollar for every time I have been asked this question, and I thought it a fitting first “Tips and Quips” post because it was asked of me once again today.

Back when I was interning with my NGS photographer friend, Joel he had just purchased the Nikon D2X and was having a terrible time with it back focusing. Cursing under his breath he said “Maybe I should just switch to Canon”. He never did but he does use Canon Rebel’s on the laser camera traps he uses to capture wildlife.  I mention this to high light that every photographer gets frustrated with their equipment. Some photographers switch back and forth like changing clothes; this is not something I will be able to afford to do in the near future.  I think it is important to highlight  that for what I do, I think Canon is the best fit  for me and this is why. If you pay attention to the sidelines at the Winter Olympics right now the majority of the lenses you will see are white meaning Canon glass. I believe the reasons for this is simple Canon pushes hard to have more sensitive and quicker auto-focus systems while Nikon pushes for higher image quality (smaller pixel size). When I stated this to the individual who asked me the question today she quickly said I want the better quality, which sound rational right? Not so fast! On a technical testing sheet the image quality might be a little bit different, but where the rubber meets the road is sales, and to date I haven’t had an editor look at my images and think they were not high enough quality because they were shot with a Canon system. To me that is the test that matters and it wasn’t so long ago that I was shooting for magazines with a pair of worn out Canon 20Ds and I never had a complaint with those ancient bodies (5 year old technology). If that isn’t enough there are plenty of top photographers who shoot Canon and they wouldn’t if there was a marked difference in quality. Also I have heard that Canon spends 10X more on research an development than Nikon so if that is true one of these days there should be a clear leader. So as for me I am a Canon man I want the fastest most sensitive auto-focus I can get because if I am going to capture that little bluebird in flight again its all about shooting on the fly. Please Respect Copyrighted Images