Thursday, August 26, 2010
Canon 60D and Sony SLT-A55
© Photographer: Bradcalkins | Agency: Dreamstime.com
In the last week two new cameras have been introduced that are of interest to me. The first is the Sony SLT-A55. It is unique in that they have adapted the Pellicle mirror idea from the 60's to modern SLRs to allow the faster phase detection autofocus to be used in movie mode. Most SLRs flip the mirror out of the way (or have no mirror like my GF1) and use contrast based AF off the sensor. Fuji makes a unique compact with some trickery up its sleeve with a few modified pixels in the center, but otherwise this is a new solution to the AF during video problem.
1. Fast autofocus during video.
2. Full time view in viewfinder allows eye level video shooting for more stability or in bright light where the screen is hard to see. No blackout between still photo shots. Should translate into faster response time after the shutter press, but on a lower priced body I doubt it beats the best.
3. Solves some of the problems with the original Pellicle mirror design: a partially silvered mirror loses light in the viewfinder - with an EVF this can be corrected with more amplification. Another issue was light leaking in the viewfinder - again no problem with the EVF sealing the body.
4. Potentially much better AF tracking during high fps shooting since the AF sensor has a continuous view. This could be a really big deal if ever adapted into the high end Canon/Nikon sports bodies.
5. Fewer moving parts.
6. Potentially allows different lens design as the mirror won't hit the rear element (Canon Pellix has two special lenses).
1. No AF when stopped down to f/8 or smaller. All phase detect camera have that issue, but not it applies to video. Still - better to have great AF down to f/8 for most users.
2. Mirror is now the dust and grime collector. I've always been warned not to touch the mirror due to its delicate surface - I wonder how that will play out over time. No dust reduction on mirror I don't think. Note that due to the mirror being away from the sensor this should mean dust won't affect the photo in the way that dust in a lens doesn't. That said, the top of the mirror is close to the sensor...
The 2nd major announcement is the new Canon 60D. I've been waiting for this to be released to decide what to do - I want more megapixels for stock, but just can't justify a 5D Mk II. 7D is very interesting but I didn't want to spend the extra only to find a similar spec'd 60D. I don't really see much video shooting for me - I have a GF1 that does a fine job of HD video for my purposes, and it is usually the camera I have with me for family outings when I want to take video. So that said the 60D announcement is somewhat ho-hum. The interface on the body is simpler, has SD cards, new grip, new batteries, same AF as the 40D, plastic body, and some of the former button functions are now in the LCD menus. Flip out screen is nice, but better for video. No PC Sync cord option. On the plus side is the same size viewfinder at the 40D, level, flash commander built in, etc. I'll have to get this in my hands to make any sort of decision.
By the way - what is with 'amateur' cameras having 18MP? I just can't imagine having lenses that can take advantage of all that for someone on a budget.
Posted by Brad Calkins