Re: Available light - higher ISO, lower resolution, better?
I'm an available light bigot, and decided against a DSLR for now,
primarily because of size/weight considerations. I've been reading
the "No flash indoor photography" thread at
, and wanted to check if a different strategy might work.
I shoot primarily snapshots in JPEG that go onto a web server, so
most higher resolutions are really overkill. I don't usually make
prints. When I used to shoot film, I used to use ISO 400 film
(actually Black's brand, probably Fuji OEM).
What camera, and what lens did you use? Just curious. I have a Canon G6 that I really enjoy; and a Canon SLR with a 28-80mm lens (I forget the model number), that I don't use. I thought about getting a 50mm F1.8 lens for low light, along with ISO400/ISO800 film -- I'm not sure that it would be as usable as the Canon G6.
The G6 works better than the S60. The 5 megapixel sensor is noisy and the F2.0 vs F2.8 is another 2x delta. In comparing noise, the G5 at ISO200 (5 megapixel sensor) is nearly as noisy as the G6 (7 megapixel sensor) at ISO400 -- especially given the higher resolution of the G6. See my recent post on G6 at ISO200/400,
I understand that boosting ISO to 400 creates noise on digital
sensors. To capture more light, am I better off reducing the
resolution setting on my camera from 2560 x 1920 (5MP) to 2048 x
1536 (3MP) or 1600 x 1200 (2MP) at the same time as boosting ISO?
My understanding of the physics is that the limited light then get
distributed across a larger coverage on the sensor.
Capture your photos at the highest resolution. Use noise reduction if you like, and then downsize your images afterwards. For my G6, I have chosen not to use neatimage, or other noise reduction software, but such software will work better on the original full size images, than on the downsized images. In other words, even if all you care about is the results for web viewing at 1024x768, you are still better off capturing at full resolution.
I had a Canon S30 (3MP), which I lost and replaced with a Canon S60
(5MP). The Canon S30 had an ISO 800 setting, and ISO 400 was
considered usable. The Canon S60 (and now the new Panasonic FZ-5 I
own) both have a ISO 400 settings, but reviews consider ISO 200 the
IMHO, on my G6, ISO200 is usable for enlargements, and ISO400 is usable if you understand the limitations. Shoot with a tripod, non-moving subjects, or hand held with the timer, use the wide end of the camera instead of telephoto, and you'll get some winners.
Thus, my strategy would be to shoot in daylight at 5MP with auto
ISO (probably ISO 80 or 100), and then interiors at 3MP with ISO
400. With limited light, I should try to stay at the short end of
zoom (f2.8 on the S60 and FZ-5), and may set the aperture at
Is there something wrong with my logic? If someone could point to
a web site that has tried these experiments, I would be interested
in the results. Thanks.
This is a really nice ISO200 result, Canon G6. Original, 3072x2304, downsized to 1136x852, no noise reduction, no other post processing. Tell me what you think. Results like these convince me that I can use ISO200 pretty much whenever I want on the G6, but at ISO400 noise is visible in printouts -- less visible on the web.
P.S. I really did look hard at the Pentax *ist DS, since I own
lenses in P-mount, but the weight of my all-glass Vivitar lens is
heavier than the FZ-5, and I can put the FZ-5 in a modest fanny
pack without issue!