We all know that mid-day is not the greatest time of day to be outside making images. Well maybe not everyone but most people that have been using a camera for more than a week. One reaction is either the conscious or subconscious decision not to make images during the mid-day doldrums. The other is to instantly turn on the auto fill flash - heck most consumer cameras automatically do this for you. For some of you searching to make better images at mid-day you can also go read up at some other sites on how to make use of old used hotshoe flashes for $4.25 and save a lot of money while looking at example images made in the Sahara desert with 14 assistants and 12 ganged SB-900 flashes, and a bunch of large diffusers, stands, etc.
Here is a more simple approach that will apply even if you decide to add additional light sources to the mix. The keyword here is decide. Deciding how to use the light that you have on hand is the key to making consistent images in just about any circumstance. They mght start out as consistently bad but that is good. You can modify one thing at a time until they are consistently good. Auto fill flash has it's place and may make "useable" images that would have been unuseable if you didn't have it but for for the most part using it with no attention to what else is going on with light in the image will not result in great results. In fact I think auto fill flash really get's in the way of most people learning how to deal with light by making them numb to what is really going on in the scene. I see fabulous images that use fill flash all the time in National Geographic and other places. The one thing that they have in common is that the photographer made decisions about the rest of the scene as well.
When the sun is really high there are a couple of things to watch for that wilth a tiny little bit of practice will pay off big time for you down the road no matter whether you decide to use fill flash, a reflector, or add another light source. A technique that I use all the time is using the sun as an accent light. Meaning position the subject (or yourself) in such a way that the sun acting like a hair light or edge light to provide separation and not the primary source of illumination for your subject. This works great for just about any circumstance and has two main variations. The first being every thing in the background is also lit by the sun and goes way bright compared to the subject - this can actually work for a lot of things by de-emphasize the background.
You go this direction you cannot be timid you really want to let the background go and lot's of things will be "blown out" technically speaking but in a lot of circumstances it's a who care proposition and there was nothing back there that you needed or wanted lots of detail. You will get a sense of what is going on. I have seen a really high end wedding photographer on the west coast that makes a living with this technique and her images are way better than the typical auto fill flash wedding crap that I see most of the time with perfectly detailed and exposed subject and background where both subject and background have really crappy light. The background has high noon light and the subject has crappy on camera flash light. Wonderful.
The other direction you can go using the sun as an accent light is with a background that is not lit by the sun but lit by the sky. This in general will give you a very high degree of separation between subject and background. This is a much more common scenario than you might think. Just take a look around next time you are outside at mid-day and note the infinte variations of backgrounds that are in the shade - cant'f find one - turn around and look the other way. The image at the top of the post is that circumstance.
So is this one. I screwed this up from a little bit from a timing perspective but she was walking toward me very fast and there was a very small window as she was walking into the shade to get the sun off of her face but still acting as a rim light. Hey I am not HCB but I will bet you he would consider this a keeper to.
One other note - your DSLR will probably get this exposure wrong. Maybe not but it will be a hit or miss thing. Most of the time your DSLR on evaluative metering will do everything in its's power to keep from blowing out the highlights - what you really want is to spot meter the face of your subject that is not in the sun and open up for about a stop more exposure (Zone VI) or so depending on the skin tone of your subject and what feeling you want in the image.
The key here is to look at what is going on with the light in the scene and make conscious decisions about how you are going to handle it. After a little practice and the wonderfulness of quick feedback with digital this will be come second nature to you. Your pictures will thank you.