Aperture Priority
I rarely shoot anything but aperture priority. Occasionally I shoot manual when I need a specific sort of control (such as controlling ambient light with flash). Many sports shooters use aperture priority, too. Here’s how I use it:
- depth of field — choose an aperture for appropriate depth of field. This doesn’t mean automatically choosing the smallest apertures, such as f/16. I will use f/16 when I really need deep depth of field, but I will shoot f/8-f/11 for distant scenes where depth of field is unaffected by f-stop; f/8-f/11 tend to be the sharpest parts of most lenses. I will choose wide apertures such as f/2.8-f/4 for selective focus effects to keep subject sharp and background soft. I will typically shoot close ups at f/5.6-f/8 to gain some depth of field, but not too much (since it is difficult to get close-up backgrounds sharp anyway, I would prefer them more out of focus).
- action — choose the wide f-stops. A pro technique is to set the lens at its widest or maximum aperture, such as f/2.8-f/4. You are looking for the smallest number you can set with your lens. Then with aperture priority, you guarantee that you always will shoot with the fastest shutter speed possible for the conditions. You cannot do that with shutter speed priority. The wild turkey seen here, for example, was shot with aperture priority, max aperture, so that as the bird moved through different levels of light, I was always getting the fastest shutter speed possible for the conditions.
The only time I might consider shutter speed priority would be if I wanted to use a very specific shutter speed, such as a slow speed for a water blur.
Some photographers are very comfortable with manual exposure, which works fine, but some photographers use it because they think they “should” in order to be a “real” photographer. I used to feel that way many years ago. But honestly, modern auto exposure systems are so good that they are faster, more convenient, and can be just as accurate. They certainly require a lot less thought about technology! And with digital, you can quickly see if your exposure is right or not by using the LCD with highlight warnings and histogram.
July 23rd, 2009 at 6:55 am
Another reason for manual is for some of the “special” shooting for post processing, like panoramas and HDR.
July 23rd, 2009 at 7:09 am
If you need to shoot a series of pictures (10-30) in a particular setting, say, outdoor wedding, portrait, or mid-day event, then you really want CONSISTENCY in your exposures. The only way to get consistency is to 1) make sure your exposure is correct using a gray card or incident light meter 2) setting your camera to manual (manual ISO, shutter, aperture). You can’t use your camera’s metering because no matter how fancy your 21st century center or matrix [scene recognition] metering is, it is still reflective metering that more than often than not, fools your camera meters. The alternative to consistent exposure is to just shoot everything in A mode and then go back to Lightroom/Photoshop and adjust exposures one picture at a time– this adds PAIN in your workflow.
As for S/Tv vs. A mode, in today’s world, you have a 3rd alternative. I actually use “ISO priority” a lot when lighting is less than ideal. Let’s say for sports, I want to shoot with at least 1/1000 second with the minimal ISO I can get. To do that, I simply set to auto-ISO, then set it to 1/1000 second and the widest aperture possible (e.g. f/2.8 on a 70-200mm). The camera will then set the minimal ISO that meets the 1/1000 f/2.8 criteria. If you over-expose even at the minimal ISO, you can play with other parameters (stop down for better sharpness, or faster shutter for better freeze action). Trade-offs.
Lastly, f/8-11 is the rule for full frame cameras. On DX/EF-S, the sweet spot is usually 1-2 stop lower For example a lot of the APS-C lenses (look at photozone.de and other sites with MTF) have center sweet spots between f/4-f/5.6, and corner sweet spots reached aroud 5.6-8.0.
July 23rd, 2009 at 7:23 am
Definitely! Thanks for reminding me, Michael. Although for HDR, I usually use aperture priority and auto exposure bracketing. That allows me to ensure minimal movement of the camera, and can even be used to create handheld HDR!
Rob
July 23rd, 2009 at 7:56 am
Interesting comment, Kevin. Thanks for sharing!
I think all photographers must find a way to make exposure work for them. I have shot in the conditions you mention, and indeed will use manual exposure, but I find no need for an incident meter or gray card. I am sure that works for you and you should use what works for you. I studied the Zone System years ago and also spent a lot of time professionally in a studio setting. The only time I liked using an incident meter was with flash, yet some of my colleagues always used an incident meter. What does that prove? That you get good exposure based on a way of working that works for you.
It is possible to get spot-on exposures with your camera’s metering system. I know, because I have done this professionally with great success. With digital, you use an auto exposure shot for your “metering”, then set a manual exposure based on how that sets up with the histogram and highlight warnings. It is possible to do this as accurately, faster, and with less gear.
I’m afraid I cannot recommend auto ISO. I feel very strongly that you should control noise and color which cannot be done with auto ISO. This is why sports pros who shoot aperture priority for shutter speed use aperture priority and not auto ISO.
Finally, I am not one who believes much in shooting test shots and evaluating real world performance of a lens with them. I think they are valuable for lens designers, but the photographer needs to shoot and see what lenses do. If this had been a pure blog about sharpness, I would have said that. I have found that my lenses, both for APS-C and Four Thirds, do perform at their best generally around f/8-f/11.
That said, I rarely shoot that way. I shoot for what is needed by the scene and the subject. If it needs a specific depth of field, I shoot for that. I typically shoot distant scenes at f/8-f/11 not for the sharpness of the lens, but because that nearly always gives a shutter speed that will hold the sharpness of the lens as appropriate.
Rob