Eleven False Statements

by John Shaw

Editor’s note: There’s a lot of photo-mythology floating around out there. Visionary Wild instructor John Shaw puts a few of his favorite myths to rest.

1.  Images for the web should be sized at 72 dpi.  First of all, “dpi” refers to dots per inch, and computer screens have pixels, not “dots.”  But “72 ppi” is also false.  Pixels dimensions are the only criteria for computer images.  1200 pixels are 1200 pixels, whether they be 1/inch or 1200/inch.  You still have 1200 pixels.  Say you have an image that’s 1000 x 500 pixels at 72 ppi.  How many total pixels is that?  1000 x 500 = 500,000.   Resize to 1000 x 500 pixels at 300 ppi.  How many total pixels is that?  1000 x 500 = 500,000.  Exactly the same.  If you’re resizing web images to 72 ppi, you’re simple adding a useless step to your workflow.

2.  Mac monitors use 72 ppi while Windows ones are 96 ppi.  Sorry, this is a myth.  If it were true, a monitor would have to change resolution depending on whether it was connected to a Mac or a PC.  Want to know roughly what the resolution of your monitor is in ppi?  Measure the horizontal width of the screen and divide this into the horizontal pixel dimension at the monitor’s native resolution.  My laptop’s screen is 1920 pixels wide, and measures about 13.5 inches horizontally.  1920/13.5 = about 142 ppi.

3.  You should set Adobe RGB in your camera if you’re shooting RAW files.  While this might affect the image displayed on the camera’s LCD, it does not directly affect a RAW file.  After all, if Adobe RGB were actually applied, the file would no longer be RAW data.

4.  For the best RAW file results, set a specific white balance in the camera.  Don’t use Auto White Balance.  RAW files have no white balance.  Just as I said above, if a white balance were applied the file would no longer be RAW.  A specific white balance is only set when the file is processed into a standard graphic file format such as .psd or .tiff or .jpeg; that is, when it is no longer a RAW file.

5.  This RAW image is how it appears right out of the camera.  Not true.  A RAW image has to be rendered in some way before you can even see it.   Exactly how it is rendered depends on the default settings of the RAW conversion software you use.

6.  You can evaluate exposure by looking at the image on the camera’s LCD.  You can adjust the LCD’s brightness on almost all DSLRs, so exactly which level of brightness would be “correct?”  Sorry, not true at all.  For that matter, the camera LCD most certainly is not a color corrected and calibrated monitor.  You can evaluate composition; you cannot evaluate color or exposure.  You definitely should use the histograms for exposure information.

7.  Always use a UV filter to protect your lens.  From what?  Dirt and fingerprints?  Then you must take the filter off for every shot, otherwise you’re shooting through a dirty, fingerprinted filter.  Use one for “protection” only if you can state from what it is you’re protecting the lens.  Salt spray?  Yes, this might be an answer, but I live about 100 miles from the ocean and on the other side of a mountain range, and if there is salt spray here, protecting my lens will be the least of my worries.

8.  12 frames/second is better than 10/frames per second.  In what way?  Neither one guarantees you’ve caught the peak moment.  Consider this:  let’s assume a shutter speed of 1/1000 second.  12 frames/second captures 12/1000 of the action, and misses 988/1000 of it.  Holding down the shutter button at the highest frame rate yields lots of images, but not necessarily the one you wanted.

9.  Always underexpose a half-stop to richen the colors.  Intentional underexposure with digital cameras is one of the worst things you can do.  It simply adds noise.

10.  Professional photographers get all their equipment free from the camera manufacturers.  Boy, do I ever wish this were true, but it isn’t.   For that matter, I wish it were true for cars and houses also.

11.  All information on photography forums is true.  You might remember back when there was an actual discussion about using Scotch® tape to clean camera sensors.  I’m fairly sure someone fell for this, and actually tried it.  We all know that it’s not Scotch® tape you should use, but duct tape, right?  (Well, I read about using duct tape on the Internet, so it must be true.)

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