Sigma SD1 Merrill: Performance

Performance
The camera is very quick to start up and shut down, has responsive buttons and dials and can potentially be a very quick shooter, both in continuous shooting mode and single shot mode.  However, as noted below, I found some serious performance problems. 

Shooting Performance
This should be a very strong area for the SD1 Merrill as its shooting performance can be excellent.  The camera can fire off five to seven shots per second in continuous shooting mode and shoot as fast as you can press the shutter in single shot mode.  But there are two problem areas that detract from the camera's performance.

The first is that I found the camera's auto focus to be unreliable in low light.  Sometimes I would fail to achieve focus three or four times in a row.  There were more than a few occasions when the camera indicated that I had focused but the image turned out blurry.  This happened despite the fact that the camera has a bright focus assist lamp.

Another issue I had was the camera's frequent writing to the memory card, which would prevent any other actions from occurring.  According to the manual, the camera has a buffer for rapid shooting that varies depending on the memory card and camera settings in use.  When I looked in the viewfinder, the camera indicated that I had a seven shot buffer.  Even in single shot mode the camera would start writing to the memory card before I'd taken all seven shots, at which point the camera became frozen until the writing process was completed.  This would take anywhere from 5 to 15 seconds.  When continuous shooting or shooting in RAW mode, the writing delay was even longer - as much as 60 seconds.  One reason for these lengthy delays may be the large file size of the images.  In "fine" mode JPEG images average about 7mb and RAW images about 60mb.

The camera uses a rechargeable lithium-ion battery pack, BP-21, which I found to last for about 300-400 images, which is not that great for a DSLR. 

Lens Performance
The 85mm F1.4 EX DG Sigma lens that was provided with the camera was superb, with sharp, clear results throughout the entire image and virtually no distortion of any kind, including vignetting, lens flare and chromatic aberration.  Colors were very natural.

Video Quality
Sigma chose not to include a video mode in the SD1 Merrill.

Image Quality
There's no question.  The SD1 Merrill produces great looking images with sharp definition, good contrast and natural colors, both in RAW and JPEG modes.  I did not notice any significant highlight clipping.  White balance is also very good.  I used the auto white balance setting, which worked well.  Other white balance settings are daylight, shade, overcast, incandescent, fluorescent, flash and custom. 

The camera's ISO ability is fair compared to other DSLRs.  While the image looks good through 1600 ISO, colors fade badly at 3200 ISO and get even worse at 6400 ISO.  Most cameras with APS-C sensors don't exhibit such significant color fading at 3200 and 6400 ISO. 

100 ISO                                                                             200 ISO

400 ISO                                                                             800 ISO

1600 ISO                                                                           3200 ISO

6400 ISO

The camera's built-in flash can be used in normal mode, red-eye reduction, wireless TTL, slow synch (which uses a slow shutter speed) and rear curtain synch (flash fires before the shutter closes).  It is possible to compensate for the flash output level without changing the exposure by pressing the flash exposure button and adjusting the level with either the A-dial or S-dial.

Additional Sample Images