Critical focus in wedding photography.

For professional wedding photographers the most critical aspects of their camera are how well it can focus (particularly in low light) and how clean the images are from noise (particularly in low light). These two abilities are what top end cameras are all about and why they cost so much.
Picture noise can very effectively be dealt with in post-production, but there is mostly nothing that can be done if your image is out of focus. Shooting your lens at wide apertures – which is common practice in low light – adds to the importance of critical focus because there is less margin for error.
On more expensive cameras you will find an option to micro-adjust each lens to the camera. This is definitely worth doing in my opinion.
There are various ways of measuring the micro-adjustment needed, but for consistency (although way over priced) the LensAlign MkII is a great device for this job. When I compared my results using this tool to the other free methods and guides for alignment, I simply found this approach to be quicker and easier to get accurate and repeatable results with.
You will get the fastest and best results if you use this tool in conjunction with tethered shooting on your monitor. For the Canon EOS 5D Mark II I used the EOS utility Live View mode to align the target precisely and then I shot tethered into Adobe Lightroom to evaluate the actual results with RAW files. I prefer to align my lenses in less than optimum lighting conditions at ISO 800, as I feel this is a better test for the focusing system and better reflects real world use. I also recommend you stick to focusing tests at the maximum distance indicated by the free Distance Tool on the LensAlign website.
The 100% crop in the screenshot above shows where you should end up after proper calibration. In this example, you can see my EF 70-200 f/2.8L IS MKII is tack sharp on the ’0’ scale reading. This was taken using indoor lighting with IS mode turned off at a distance of 10m at 200mm f/2.8. Seriously sharp eh!
As a quick tip when aligning the target hold your iPhone up behind it so the light can shine through the target sights – when you can see a clean circle of light coming through to the camera via LiveView, you are in perfect alignment.
Visualsnap | Wedding Photographer Kent
