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ISO is the measurement of the camera's sensor/film sensitivity to light. It is one of the 3 ways to create a well exposed image (The other two being Aperture and Shutter Speed). Typically, a higher ISO for a correctly exposed image will result in the image being more noisy/grainy.

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7answers
601 views

Can ISO vary on different cameras?

We all know that [ISO] + [shutter speed] + [aperture] = a great picture. Now, let's take two different (very!) cameras: Nikon D3100 vs Nikon D800 and set them on Aperture priority. Settings for the ...
0
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1answer
1k views

What does ISO stand for? [duplicate]

I've recently been learning how to use a camera, and was wondering what ISO stood for?
0
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2answers
544 views

Why does a higher ISO hinder higher video bitrates in Magic Lantern? [closed]

With Magic Lantern it's possible to increase the video bitrate up to a point your memory card can no longer keep up and Magic Lantern will notify your recording has stopped. While i can understand ...
2
votes
2answers
689 views

Why does EV increase as ISO increases?

From what I understand, the lower the EV value, the more exposed (bright) the image is. EV decreases as aperture decreases. More light gets in with lower apertures. EV decreases as shutter speed ...
6
votes
5answers
381 views

When determining exposure, is ISO typically taken into consideration secondary to aperture and shutter speed or is it equally as important?

In other words, do professional photographers typically pick the aperture and shutter speed they want and then after those are picked adjust the ISO until their exposure meter shows the shot as being ...
4
votes
2answers
232 views

Why does the ISO change with the shooting mode when the aperture and shutter speed are constant and using a flash?

I have a canon 60d, Canon EF-S 17-55mm f/2.8 IS USM lens, and a Canon Speedlite 430EX II TTL flash. I like to use the manual modes, such as Av and Tv but I am having some difficulties when using the ...
8
votes
2answers
783 views

Why doesn't a Medium Format camera exist with good performance at high ISO?

I have had a look at enough medium format offerings, but all the products seems to offer many megapixels and poor performance at high ISOs. Why doesn't a brand exist to offer slightly lower ...
7
votes
1answer
763 views

Film ISO and Push/Pull Processing

I am looking to start shooting film and have been having a look a different 35mm film. What confuses me is film that can be shot at different ISOs/exposure bias. For example Kodak says that Portra 800 ...
4
votes
2answers
267 views

Wedding cameras - disposable or ebay compacts + film

For a wedding I was thinking of trying to get some better quality disposable cameras. The highest ISO disposables seem to be 800 colour or 400 B&W (I would like to get a mix of colour and ...
7
votes
3answers
3k views

Why shoot a daylight outdoor photo at high iso? [duplicate]

Possible Duplicate: Are there any situations in which it makes sense to raise the ISO in bright daylight? I was looking at this image (from From Reuters blog ...
3
votes
7answers
3k views

Is noise related to shutter speed as well as ISO?

I understand that as I increase ISO, I'll increase the amount of noise in the resulting image. With a constant aperture I can decrease ISO and slow the shutter speed (assume a non-moving subject, ...
17
votes
5answers
4k views

What is so special about ISO 1600?

I have heard many times that to minimize noise, the highest ISO you want to use is ISO 1600, and that no matter what camera or sensor you use, once you have passed this (ISO 1600) threshold, the noise ...
12
votes
2answers
438 views

Why is the amount of photos that fit on one card dependent on ISO?

I have a Canon 550D with a 16GB SD card. I noticed that, when in P-mode, if I choose an ISO of 100 I can shoot 595 raw files on an empty card. If I choose an ISO of 200 this is 590. And if I choose ...
5
votes
1answer
343 views

How can a newer camera increase ISO while decreasing pixel size?

I am a bit confused as I am considering to upgrade my canon 350D to 600D. The pixel size has reduced from 6.4 microns to 4.3 microns, however, top ISO has increased from 1600 to 6400. How did that ...
30
votes
6answers
4k views

Why is there an ISO setting when shooting raw?

Raw files are supposed to contain mostly unprocessed data from the sensor. What's the point of having an ISO setting if it doesn't affect the amount of photons counted, but only provides ...
8
votes
4answers
406 views

What exercises can I do with a fully automatic compact camera to help me learn?

I own a Nikon Coolpix L120 camera. It's fully automatic. I am really interested in photography. Can anyone suggest me some exercises or experiments to do with this camera so that I can make a good use ...
6
votes
1answer
188 views

Best film and shutter speed for Mansfield Skylark

My daughter picked up an old Mansfield Skylark camera at a yard sale. Can anyone recommend a film type/speed and shutter speed for overcast daylight conditions? The shutter speeds are simply 'B' ...
3
votes
3answers
512 views

Can you tell how effective a camera's high ISO images are from the specs?

My current camera, a Canon 50D has OK image quality at 1600 ISO and its not really very usable above that. I know that all the manufacturers publish an ISO range for their bodies. But just because ...
8
votes
3answers
438 views

Variable ISO Sensor: Possible and/or Useful?

This answer to the question about how ISO is implemented in digital cameras seems to imply that each photosite (i.e., pixel) can have its ISO set independently. If this is true, then I would think ...
3
votes
3answers
3k views

Night-time football game under field lights

I am shooting a little league football game at night under the field lights for the first time amd I have a few questions to ask. I will be using the Canon EOS 60D camera with a Canon 24-70mm 1:2.8 L ...
5
votes
1answer
288 views

When is high ISO noise not noticeable?

I noticed that sometimes when taking pictures with my D5100, they come out with very little visible noise with ISO 800 and up, for example this picture. It was taken at ISO 1600 if I remember ...
12
votes
4answers
981 views

Why is sensor sensitivity called “ISO”?

I was curious to know how the term "ISO" was coined for referring the image sensor's sensitivity. Is there any reason or circumstance that contributed for terming "ISO"? Also, does ISO has a literal ...
2
votes
2answers
682 views

Can ultra-high ISO ever yield good results? [duplicate]

Possible Duplicate: Is high ISO useful for photography? My camera can apparently extend to really high ISO's, however I see serious noise over 2,000 ISO at any shutter/apeture combination. ...
7
votes
3answers
1k views

how the camera determines correct aperture and ISO in bulb mode?

Consider that the camera is in shutter priority and the exposure time is set to bulb mode. Now the camera doesn't know how long the shutter is going to be open in advance and so how does the camera ...
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3answers
686 views

How to calculate f-stop and ISO equivalents for a Lomography Spinner 360°?

In this review, there's this paragraph explaining f-stop and ISO equivalents: The two aperture settings are marked with the sunny and cloudy symbols which equate to f16 and f8.0 respectively ...
2
votes
3answers
3k views

Noise Issue / Canon 5D Mark II

Just curious if anyone can help with this? I am using a Canon 5D Mark II and it seams to be having noise issues at ISO 250 and up and especially at ISO 400? What is going on? In low light when my ...
11
votes
4answers
2k views

Why is the lowest ISO always 100?

The lowest ISO on digital cameras always seems to be 100. It would sometimes be useful to have much lower ISOs, mainly for long exposure photography. What isn't there any 50, 20, or even 10 ISO ...
12
votes
2answers
1k views

What exactly is “base ISO” and how do I find what is base ISO on my camera?

If I understood correctly, base ISO is in full stop steps from the lowest possible ISO setting on my camera. For example if the lowest setting on my camera is ISO 100, than the following table would ...
3
votes
2answers
5k views

How do I see settings afterwards on my Nikon D5100?

I am quite new to DSLR photography. What I can't figure out is how to see the settings for the photo after I have taken it. For example, if I take a photo with 1/200, f5,6 and ISO 200. Can I see it ...
2
votes
7answers
892 views

Why do these images taken at significantly different ISO appear equal in quality?

How come I can't tell the difference in quality of these two photos, even though one is shot at ISO 160, and the other at 1600 ? Note: EXIF data has been stripped from images below by imgur saving ...
5
votes
4answers
412 views

How do I properly determine which camera is better in low light?

This question is motivated by the fact that I'm trying to decide between the the Canon 5D Mark III and the Nikon D800. I really would prefer the one that will perform better in low light. As far as I ...
13
votes
5answers
2k views

Do ISO values for Film and DSLR cameras have 1 to 1 correspondence?

For example, if we have a film with ISO/ASA speed of 100, is it equivalent to setting ISO = 100 on DSLRs?
5
votes
3answers
1k views

Does a high ISO generally result in bad dynamic range and less accurate color?

I have a Pentax K-x. I've had it set on "auto ISO up to 6400" for a while now, and I'm starting to wonder if this is making my images worse. Honestly I don't trust myself to tell. Does a high ISO ...
6
votes
2answers
719 views

How did film photographers overcome constant ISO/ASA values in low light situations?

Today in Digital SLR era, when I find myself in low light situation in a place that I can't use my tripod or I don't have it, and still don't want to get blurry images, I use the widest aperture which ...
2
votes
2answers
799 views

If I need the higher ISO anyway, is there any downside in using Fujifilm's extended DR mode?

Fujifilm has an extended dynamic range mode, which is in some way linked to ISO. The X-Pro 1 has a sensor with a base ISO of 200; if I enable "DR 200%", the minimum possible ISO increases to 400, and ...
5
votes
3answers
3k views

Why is my ISO so high when shooting indoor photos with flash

I have a Nikon D5100. When shooting indoor photos using the built in flash, the auto ISO changes to 1600 or so. Doesn't the flash produce enough light so that the ISO would stay at 100 or so? ...
2
votes
3answers
6k views

What is the relationship of aperture, focal length, and ISO in a SLR?

I was using Nikon digital camera, and recently bought a Canon 550D. I am totally new to SLR. I am not familiar with SLR terms: Aperture, focal length and ISO, and their relation to one another. What ...
31
votes
7answers
10k views

What are the advantages and disadvantages of using auto ISO on a DSLR?

What are the advantages and disadvantages of using auto ISO on a DSLR? Using manual ISO obviously gives you more control, but auto ISO may mean that you get "the shot" under quickly changing ...
5
votes
3answers
591 views

Why am I getting such high noise when using ISO 320/640?

I'm taking photos at night with a GH1 at ISO 640 and getting a ton of noise in the dark areas. I've seen a bunch of other peoples night time photos and they never have this much noise. I tried using ...
11
votes
3answers
3k views

What settings should I use to photograph aurora borealis with a wide angle f/4 lens?

I've tried my first night photography of the stars last week. Most articles I've seen were recommending a fast lens, fully opened, @ ISO 800 and about 20 - 30s exposure, etc. Unfortunately, my only ...
4
votes
4answers
774 views

Is higher ISO noise evenly distributed, or does it affect colors differently?

It's obvious that higher ISO affects the photograph by adding noise or grains. But will that grain or noise be distributed equally over all parts of the photograph, or will it specifically affect ...
6
votes
1answer
908 views

Why does the camera default to ISO 400 in auto ISO mode with flash?

I've observed this behaviour on my Canon 550D, and I was wondering why it didn't use a lower or even variable ISO. I'm not sure if this is a camera/brand specific setting. Is there any particular ...
5
votes
1answer
477 views

Bracketing with ISO or exposure time?

With old cameras, you had film with fixed ISO and you could bracket your shots by either adjusting the f-stop or exposure time. Normally, if I have enough light, I prefer to keep the f-stop constant ...
12
votes
9answers
6k views

Why aren't my night shots sharp even when I shot at ISO 100 on a tripod?

I recently purchased a tripod because I really want to do some night photography. I have tried practicing with street lamps, moon shots etc with my Canon 550D and 70-200 f/4L and most of them are shot ...
7
votes
4answers
1k views

Should I prefer raising ISO or lowering the shutter speed in a low light condition?

Example: 1. A "still" object/scene. 2. Night time. 3. The only light source you have is: a tubelight on a wall. Provided, you want sharpness all around so you won't maximize the aperture. Flash ...
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votes
4answers
3k views

What is the quantative relation between flash guide number and ISO?

I found that formula on the Internet: Guide Number = (Shooting Distance * Aperture) รท ISO Sensitivity Is it correct? If it is could someone please explain why ISO is related to guide number in this ...
9
votes
1answer
2k views

What film should I use for black and white outdoor 'formal' shots?

I'm wondering what type of black and white film is best to shoot good-quality outdoor photos that capture the quality of the trees, etc., and still show detail in people's faces. Is there a ...
4
votes
4answers
362 views

Are there any situations in which it makes sense to raise the ISO in bright daylight?

Are there any situations in which it makes sense to raise the ISO in bright day light? For example, this pic has been taken in bright day light with ISO 3200, f18, 1/1250: ...
4
votes
1answer
165 views

What makes a good sample image for ISO comparison?

To be more specific this image is always used by Digital Photography School for ISO comparison. What are those features that make this image suitable for ISO comparison.
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votes
2answers
490 views

Assuming a perfect sensor, what is the physical limit of ISO/pixel area?

Assuming that camera manufacturers can eventually make the perfect sensor that introduces no electrical noise to the signal, at what point (measured in ISO/area of a pixel) will shot noise be so ...