As I hinted at a few weeks ago, there’s a new camera in the Deauxmayne — a shiny new Canon EOS 7D, kitted with a Canon 28-135/3.5-5.6 IS USM lens. I expect this will be the first of several pieces where I describe my real world experiences with this really nice camera.
Yesterday, trying to take advantage of a very light snowfall, Casey and I decided to get together just before sunrise to do a little shooting. This was the first real excursion for the 7D, and needless to say I was excited. It was cold, cold, cold and windy, making for miserable air conditions. However, the sky was gray, and I thought that might help keep the shadows to a minimum for stuff on the ground. We wound up at MoBot, and I spent the biggest part of my time photographing some of the water features that wander through the garden. I fired off what looked to be terrific shots with the new camera, using both the kit lens, and my trusty 100-400/4.5-5.6L IS USM lens.
After almost five hours in the cold, I came home, got some lunch, warmed up, and began to download images from my card.
One thing I noticed right away was that I had almost 500 images on the card. That seemed odd, as I was pretty sure I hadn’t blasted away with quite that frequency. The key was something I noticed while shooting. I was using the “cloudy” white balance setting, and noticed that the cloud indicator on my panel was blinking. That was weird. What I discovered (after I got home) was that I had accidentally set up bracketed white balance when I was trying to set up bracketed exposure. Not a biggie, but it was a bit of a mystery. This meant that almost everything I shot actually recorded three images using this bracketed white balance. I didn’t even know you could do that. Cool, and something I’ll have to play with in the future.
I imported my images into Lightroom 2.6 (freshly updated with support for the 7D), and noticed that most of my shots were soft. Now, I know that the 28-135 isn’t an L lens, but I was surprised to see so much softness, especially since I had manually focused everything, and most of the images have their focus “fine tuned” using live view. While it didn’t ruin my photos, it did make them just too soft for my tastes.
Today, I decided to experiment to see if I could reproduce the problem.
I decided to enlist the help of a fantastic model for trying to figure this issue out. He’s got loads of character, and doesn’t complain about the pay. 🙂
The setup was essentially the same as I used outdoors at MoBot — 7D, 28-135 (zoomed to 135mm), two second self-timer, ISO 160, f/8. I shot three images — one using autofocus (something I didn’t do in the field yesterday), one using manual focus fine-tuned with live view, and one using manual through the viewfinder. Here’s what I found. (Click on the images below to see the full size crops of the samples I shot.)
The autofocus shot was easy. The 7D chose to focus on the upper left part of my model’s hair, and from what I could tell in the zoom up of the shot, it seemed to nail the focus.
The manual focus shot was just as easy. However, here the “human element” of my eyes starts to have potential of influencing the results. I did the best I could, and focused on the nose of my intrepid model.
And last was the manual focus using live view to help dial in the focus. Again, my target was the nose.
From this series of images, it was obvious that autofocus was working fine, manual focus using my eyeballs was good, but manual focus using live view was obviously not focusing on what the screen indicated was being focused on. From my best guess, it appears that manual focus using live view actually brings a clearer image from a little farther away than what is being seen on the screen on the back of the camera. You can see this by looking at the hair on the upper left of the model.
So, what do I do about it? Well, some research about live view and its limitations, more trust of my eyeballs through the viewfinder (and the new 100% coverage viewfinder in the 7D rocks), and more trust of the autofocus system in the camera. It sure seems weird that what you see on the screen is not what you get.
Stay tuned…
Update #1 : I neglected to mention the dedicated live view button. This is a tremendous improvement over the implementation on the 40D. And I should probably mention why live view focus assistance for manual focus is so important to me. When I’m shooting macro work, I really wanna nail the focus within the plane of focus in those tight quarters. Live view helps with that because I can zoom the image 10x over what I can see through the viewfinder, helping me get the focus right where I want it.
Update #2 : The lens in question I had done a rough AF Microadjustment to via the Custom Function menu. This lens (as well as the rest of mine) needed an adjustment of -7. I did this using a test screen on my laptop, as suggested by several folks on the web. I recognize that this isn’t likely the best scenario, but it’s what I had available to me. The interesting thing is that when I turn off the AF Microadjustment for that lens, my focusing with live view seems to be more what I see on the screen. It almost implies that the camera is making an adjustment, based on the AF Microadjustment data, despite the lens sitting in manual focus mode, but only when used with live view.
Of course, I could be all wet on this.