PhotoWalkPro

I was working on some images yesterday when I discovered something about the Adjustment Brush that I never knew before.  While burning in an area of the image, I was wishing that I could use the brush for straight lines like I do in Photoshop.  If you want to paint a straight line in Photoshop, I simply click with the brush in one spot and then hold down the Shift key and click in another area and Photoshop draws a straight line between the two spots. Read the rest of this entry »

I was reading an email that I had received from someone that had purchased my Canon 50D: From Snapshots to Great Shots book and they asked me a great question.  How do you know what F-Stop to start with? This is actually a pretty common question and it’s one that I heard several times over the past couple of weeks while teaching a photography class in Malaysia.  The truth is that there is no simple answer.  A lot of the decision depends on other factors that go in to determining an appropriate exposure setting like; What is the best ISO for the scene? Do I need to use a fast shutter speed because I am going to be hand-holding my camera? How much light do I have to work with? and on and on.

Depending on the subject you are shooting, you will want to vary the amount of depth of field in your image.  Remember that there is only one plane of focus but the depth of field will render a range of acceptable focus depending on the selection of the aperture.  This also has a lot to do with your distance to the subject and the length of the lens.  Wide angle lenses have a greater apparent depth of field due to the wide angle of view, which makes everything look smaller and thus sharper.  Remember that everything looks sharper and more in focus when it’s smaller, which is why I always tell people to zoom in on their LCD screens.  Everything looks great on a 3″ screen.  A longer lens will offer a more narrow field of view and make everything look larger.  Long lenses can also produce a more narrow depth of field than wide angle lenses.

So with all of these things to consider, where does one start?  Well, you could start with your sharpest aperture setting.  This will usually be one of the f-stops in the middle of the range of available f-stops for your lens.  It is also referred to as the sweet spot and it’s usually somewhere around f/8 or f/11.  This doesn’t mean that you should always shoot at f/8.  For example, if I am shooting a landscape or panorama, I will try to use a smaller f-stop (f/16 or 22) to get a greater apparent depth of field from near to infinity.

If I’m shooting a portrait, I will tend to go the other direction by selecting a larger aperture opening (f/4 or 5.6) so I can narrow the depth of field and place more emphasis on my subject while blurring distracting background objects.

It’s possible to see the effects of your aperture setting as it relates to depth of field by using your camera’s Depth of Field Preview button.  Most lenses do not close their aperture down until the moment the photo is captured.  This is done so that you have the brightest possible view in your viewfinder.  When pressed, the DOF Preview button will close the lens down to the selected f-stop and will allow you to actually see how much depth of field you are getting at the chosen f-stop.  It also makes the image in the viewfinder appear darker at smaller f-stops due to the lower amount of light coming in through the lens when it is stopped down.  Note that not all cameras have a DOF Preview button so consult your owner’s manual.

While the DOF Preview is a good starting point, the only way to really determine just what the proper f-stop should be is through experience.  Sometimes it’s a good idea to shoot at multiple f-stops just to see which one you like the best.  Over time you will develop an eye for what will look good with a lot of depth of field and what would look better with just a little.  From that point you will be able to adjust the other camera settings to get just the look you are after.

See, I told you it wasn’t simple,  but with practice, it will get easier.

For a little more on Depth Of Field, check out my post on Hyper Focal Distance.

Most photographers know that the tripod is an indispensable tool for capturing long exposures but so often I see it used in an unstable manner.  Most tripods have a center column that can be raised to offer an even higher vantage point for your camera.  The problem is that the higher the column is raised, the more unstable your camera becomes.

Think of it like a tall skyscraper.  As it reaches further up into the sky, it actually moves from side to side as a result of the wind.  This is the same effect that you can get from raising your center column.  And though you won’t get a 16′ side to side motion like the Sears Tower, you will get enough motion to add a soft blur to your image, especially on a windy day.  To ensure that you are getting the maximum stability from your tripod, keep the column all the way down so that the camera is resting at the apex of the tripod legs.  This position will provide maximum stability for your camera and help you to get tack-sharp images.

A while back I posted a video on how to set up the Nikon D300 for shooting HDR using the Auto Bracketing feature (click here to read the post and watch the video).  I received a lot of emails about the tutorial, most of which asked about other cameras and how to set them up to do the same thing.  Unfortunately I don’t have the resources to answer this question for every digital camera out there but I can give a few pointers that will work for the majority of dSLRs and a few point and shoot models to boot.

The first thing you will need is a tripod.  This is important for two reasons. 1) The images need to be perfectly registered to achive a good HDR result. 2) You won’t be able to use the continuous shooting mode because you will be making manual changes to the exposure, which means that you will not get good alignment of your images by handholding the camera.

The next step deals with making the exposures.  For a good HDR image, you should try to use at least 3 images to cover the entire dynamic range of the scene.  I use 2-stop increments and get pretty good results.  There are times when I will need 5 images but 3 is my norm.

Getting the exposures without an auto-bracket feature can be pretty straight forward.  The first option is to use the Exposure Compensation feature of your camera.  Most cameras will allow for +/- 2 stops of compensation, if not more.  You should have your camera set to Aperture Priority and select the aperture that you think is most appropriate for your scene.  After setting the aperture, take your first picture.  This will be your normal exposure.  Next, find your exposure compensation dial/button/setting and dial in -2 stops and take another image.  Finally, go back to the compensation and dial in +2 stops and take your last image.  You should now have 3 images that are ready for HDR processing.  By the way, if you are using an auto-focus system (and who isn’t these days) you should set your focus for the normal image and then turn the lens to manual focus to make sure it doesn’t shift between exposures.

The other way of getting your bracketed shots is to use the Manual mode on your camera.  You can start off by placing the camera in Aperture Priority and taking a meter reading with your selected aperture setting.  Let’s say the meter is giving you a reading of 1/250 at f/11.  Remember that reading and then switch to Manual and dial that setting in.  After taking your first image, simply change the shutter speed to 1/60 and take a shot and then 1/1000 and take another, remembering not to change the aperture between exposures.  You now have your 2-stop bracketed images for making the HDR image.

You can see that, with all the changes that you will be making to the camera, the use of a steady tripod is really key to getting a great HDR shot.

The other piece of advice I would give everyone is to sit down with your owners manual and look up Bracketing or AE Bracketing and see if there isn’t a built-in solution for your camera.  You might be surprised at what you find.

You’ve probably heard me talk about the Hoodman HoodLoupe in the past and what a great tool it is for shooting outdoors.  By sealing the LCD into a light tight environment, the LCD screen can then be easily seen even in the bright sun of the beach.  It’s something that I try not to leave at home if I know I am going to be shooting outdoors.  Now I have an even greater incentive for keeping it close by, in any shooting situation.  It helps me see the screen with my old eyes.

Just the other day I was shooting on a tripod and the camera was up pretty high, shooting straight down.  I was only able to get about 6 inches above the camera to review my screen when I had one of those defining moments that can truly be depressing…  I couldn’t see the screen clearly!  Yes, my eyes are starting to change and I now need reading glasses to see very small text and objects that are closer than about 12″ from my nose.  It sucks when you realize you are getting old but it was even worse to realize it and not be able to overcome it at the time.  That’s when I dug out my Hoodman HoodLoupe and pressed it to the rear LCD and hit the playback button.  At first I was worried that everything would look soft but then I remembered that the loupe has a diopter adjustment which made it perfect for close inspection of the screen.  Sure enough, a little fine tuning of the top eyepiece on the loupe and my LCD screen was tack sharp from only 2 inches away.  The loupe doesn’t magnify the screen, it simply refocuses so the eye can see it sharply and, just as important, without glare.  I might just have to go as far as attaching it to my camera strap so I can’t ever leave it behind by accident.

Adjusting your Camera -

And while I am speaking of diopter adjustments, I got a great tip on correctly adjusting the diopter on my Nikon DSLR from some very smart Nikon Tech Reps the other day.  You probably know that the diopter adjustment is that small knob or slider switch on the side of the camera viewfinder that adjusts the focus of the viewfinder to accommodate folks that wear glasses.  It’s also helpful for those of us whose close-up vision is starting to get a little weak.  What you might not know is that the best way to adjust the diopter setting is without a lens on the camera.  Here’s how it works, take your lens off the camera, turn the camera on (some models do funky things in the viewfinder until they are turned on), point your camera at a white wall, look through the viewfinder and then adjust the diopter until the focus points look sharp.  That’s it, you are all set to replace the lens and take some photos. Apparently having the lens attached when changing the diopter can slightly fool the eye into thinking the screen is sharper than it is.  Removing the lens means that you are only adjusting for the focus screen.   Granted, this isn’t as important if you only use the autofocus but if you ever plan on manually focusing your lens, it can make a huge difference.

That’s a wrap for this Wednesday.  I hope to see you here tomorrow.