Yesterday we decided to do a low light comparison test between our Sony DSR-PD170 and our EX1.
Unless you've been living alone on an island for the last few years you already know that the PD170 is the current low light king in the MiniDV class of video cameras. Heck, it's even the low light champ in ANY class of handheld-style camcorder. There are a lot of folks out there asking the same question I've had ever since Sony originally announced the PMW-EX1: is this an HD replacement for the PD170?
Okay, on with the testing. We set up the two Sonys side by side and pointing into the darkest corner of the room, which contained a couple of bookshelves with (you guessed it) some books and several photos in various types of picture frames.
Right off, let me say that this was not a scientific analysis of the low light capabilities of these two cameras based on luminance values, etc. but simply our perception of brightness looking at the flip out viewscreens. I don't even own a light meter.
Test one. The PD170 was set to 60i, 1/60 shutter speed, iris wide open and picture gain at 0. The EX1 was set to 1080p, shutter speed 1/60, iris wide open and picture gain at 0. During all three of these tests the zoom position of both cameras was at full wide (no telephoto). We look at the viewscreens of both cameras to see which one has the brighter image.
(Click on the thumbnails for larger images.)
Test two. Both cameras stay at the same settings except now they both have +9 dialed in on the picture gain.
Here's the difference: there's considerably less eye strain trying to pick out detail in the EX1 image than there is looking at the PD170 image, even though the PD170's picture is a bit brighter. Looking closely at the two viewscreens we can see a certain amount of picture noise from the increased gain setting, but ONLY in the PD170 viewscreen.
Test 3. Both cameras still at the same settings but now we crank up the gain to +18 on both. In the PD170 viewscreen there's now 100% zebra bars showing on the edges of some of the books and on some of the picture frames.
On the other hand, the picture in the viewscreen of the EX1 now also has 100% zebra bars on the same objects and in the same places on those objects.
The pictures also show that at plus 18 gain the EX1 actually has more noise than the PD170. At 0 picture gain it appears that the EX1 has less noise than the PD170 but then at plus 9 it would seem that there's a reversal where the PD170 has a bit less noise than the EX1. Where the changeover occurs where the EX1's picture noise becomes noticeably more than the PD170's picture I may find out in a future test, but most likely someone will beat me to it.
And the big surprise? At +18 gain on the EX1 there's substantially less picture noise than the PD170. The EX1 does have some noise but the actual noise grains are much smaller, presumably because the image pixels are so much smaller than the ones on the PD170's chips.
I'm going out on a limb here and will say that the noise in the EX1's picture is at least 60% less noticable compared to the PD170.
That said, the images from the EX1 are brighter than the PD170 by a small amount in all tests.This fact really surprised me. So much for worrying that the new Exmor CMOS sensors in the EX1 were going to be the Achilles heel with this camera. I would have been happy just seeing the SAME amount of picture noise as the PD170 has, but this.........well, this totally blew me away.
Read part 1 of Don's "Real Time Report" on the EX-1, on his very first shoot using it.