Why does indoor window light still require a relatively high ISO?
Asked 3/16/2014
8 views
2 answers
0
I’m shooting portraits indoors using only natural light, with the subject facing a large south-facing floor-to-ceiling window. I expected the scene to be bright enough for something like ISO 100–400, but my exposures are closer to around f/3.2, 1/60s, ISO 640 on a Canon 5D Mark III. Is there likely a camera setting or metering issue causing this, or is indoor window light simply much dimmer than it appears? I’m also wondering whether advice to use ISO 100 indoors is realistic if the subject may move.
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
12y ago
2 Answers
6
It would take a rather brightly lit room to get your ISO down that low. I've got a low hanging, 5 light fixture in a small white room and I just metered f/3.2, 1/60 and ISO 1250. So, bright sun is definitely going to help, but ISO 200 or 100 inside, at f/3.2, without flash is an impossible dream.
You either need a faster lens (like a f/1.4) - but that is going to require some razor thin depth of field probably by setting it really low. Or you need a flash. If you haven't used a 'real' flash before - they have a bad rep till you get to know how to use them either bounce-style or off camera.
If you really want to shoot that low ISO inside, get a flash. Its well worth the investment.
But frankly, a Canon Mark III shooting at ISO 640 is completely fine. The noise really should be fine for a Full Frame camera at 640. Of the things to worry about, I wouldn't cry too much about it.
Originally by user1917. Source · Licensed CC BY-SA 4.0
user1917
12y ago
0
Generated from our catalog & community — verify before relying on it.
Most likely nothing is wrong with your camera or meter — indoor window light is usually much dimmer than it looks to your eyes. Our vision adapts strongly, but a typical home interior can be hundreds of times darker than direct sunlight. Even a big window only admits light from one direction, so the room is still relatively dim compared with being outdoors.
Your example exposure is believable for indoor natural light. On a 5D Mark III, ISO 640 is not unusually high and should still give very good image quality. Trying to force ISO 100 indoors while keeping 1/60s for subject movement is often unrealistic unless the room is extremely bright.
If you want lower ISO indoors, your practical options are:
- use a faster lens (for example, a wider aperture),
- use a slower shutter speed if the subject is still,
- add flash, ideally bounced or off-camera.
So the main issue is not bad metering — it’s that the scene is darker than expected. Advice like “always use ISO 100 indoors” is not generally realistic without additional light.
Recommended products
UniqueBot
AI12y ago
Your Answer
Related Questions
How do I balance warm ceiling lights with cool window light for indoor photos?
Is flash really bad for food photography, or just direct on-camera flash?
Which window direction gives soft indirect daylight in different hemispheres?
How can I test a lens's sharpest aperture indoors, and are my D7000 shots actually missing focus?
Why do my Panasonic FZ82 indoor photos look grainy even at ISO 100?