Friday, February 3, 2012

Focal length examples

Someone was looking to see what various focal lengths actually look like and I thought it was a great question because, while seasoned photographers have the numbers ingrained in their brains, we shouldn't forget that they are abstract to people new to photography.  So what does 10mm, 20mm, 30mm and even 500mm really look like?  Just look at the examples below!

Keep in mind that the distance from the camera to the tree is 10 meters (about 30 feet) and the knot on the tree that you can see towards the end of the series is 6cm (2.5 inches) across.

Also, these example photos were taken with a cropped sensor camera.  Most of the mid to entry-level DSLR's have cropped sensors in them.  Full frame cameras are usually found in the pro line of whatever brand you use and using one of those would produce slightly "wider" or "less telephoto" images than the examples below.  But assuming you have the type of camera that most people have the examples below should be very close to what you'd see.

Focal length example: 10mm

Focal length example: 20mm

Focal length example: 30mm

Focal length example: 50mm

Focal length example: 100mm

Focal length example: 200mm

Focal length example: 300mm

Focal length example: 400mm

Focal length example: 500mm

Thursday, February 2, 2012

Stacking photos for star trails.

Stacking photos allows you to use several photos to create an effect that you may not be able to produce with one shot alone.  In the case of star trails it allows you to create longer star trails than you may otherwise be able to achieve.  You can even go long enough to get circular star trails!

Since we'll be working with a fictional photo to make the idea more clear, you may want to check out some examples of the types of images we're talking about producing from our multiple shots:  Click here for link.

So, let's get to the how-to.  The idea is to take several shots of the sky with short star trails and then combine them together to get the longer trails that you want in your final image.  The illustration below should help you visualize what we'll be doing:

So, assuming you have the above 3 photos and you want to stack them to produce longer, circular, star trails, here's how you'd do it in Gimp.
  • Open all 3 photos as layers in Gimp.  (If you are not accustomed to working with layers in Gimp, please click on the menu on this blog and read up on how to use layers under "Image Editing".)
  • Open the "Layers" menu if it does not open automatically.  (It's in the "Windows" menu under "Dockable Dialogues" and then "Layers").
  • Click on the image above the "Background" layer in your layers dialog box.
  • At the top of the "Layers" box, click the down arrow to select the layer "Mode".
  • Choose "Lighten only".
  • Do the same for all the other layers except the "Background" layer. 
  • That's it!
The "Lighten only" mode allows only lighter things to show through the layers.  This is perfect for star trail photos since the star trails are lighter than the sky that's covering them in the other photos.

Tuesday, January 10, 2012

Carrying a camera at all times

Many photographers carry a camera with them everywhere they go so that, whenever a photo opportunity presents itself, it can be captured.  For beginning photographers this is good advice.  Beginners can get plenty of practice at trying new angles and perspectives to learn to compose a shot well, or even just learn what makes an interesting image..  But as you become a better photographer you start seeing less and less “keepers” coming from these happened upon photo opportunities.

The reason the good photos fall off as your photography gets better is that there comes a time when you've made all the big leaps in learning how to improve your photography from the camera side and you start finding that something called "quality of light" is what makes others’ photos better than the ones you’ve been taking.

Quality of light is what makes landscape photographers get up before sunrise to catch the warm light of sunrise on a hillside, tree, or rocky cliff.  It makes macro photographers hope for an overcast day, and makes architectural photographers get ready just before dusk to capture that magically blue sky balanced perfectly with a building's inside or outdoor lighting.  In short, it’s the exact opposite of happening across a shot.  A lot of planning and forethought go into capturing photos with the best possible (natural) lighting.  

When this realization is made it's easy to decide that photography is work and that simply carrying a camera around and keeping an eye out for photo ops won't yield any significant successes.  In fact, that's what this blog post was going to be about.  The fact that good photography takes work and planning.  But I didn't finish the post, so I left it in draft form to finish later.  Then on Saturday I ended up proving my post wrong when i came across the scene below and was happy I had my camera with me so I could capture it:

Beach Sunset

So, I'll leave the question of whether or not to carry a camera at all times to the reader while noting that you can increase your chances of getting good shots by paying attention to the quality of light and shooting accordingly.  If you see a sunset, it's instinct to shoot it, but make sure you turn around too and see if the warm light isn't putting your best shots behind you.  Make the best of an overcast day by focusing on macros, and use the twilight hour to concentrate on architectural photo opportunities.