When To Increase ISO?

[jwhite461]

??? I know that it takes practice shooting under variable lighting and changing conditions, but is there a rule of thumb as to when or how much to increase the ISO setting? I shoot with a Canon 10d, 17-40L, 28-135 IS, and 50mm f1.8, mainly people :?.

Thanks in advance,
Jeff

[roanjohn]

When there's not enough light.............

I only change my ISO when I need a faster shutter speed. It's there to avoid motion blur........

Rule of thumb, you always want to shoot in the lowest possible ISO - it gives a cleaner image and higher dynamic range.

Hope this helps.

Ro1

[stuartf287]

You might try switching your camera to the green box setting and then take a look at the ISO value it sets automatically. Just a thought.

[scottbergerphoto]

As already mentioned, you want to use the ISO that will give you the shutter speed you want/need and the lowest amount of noise. Higher ISO's give more noise. One of the advantages of the larger sensors in DSLR's over P&S's is that even though both have the same amount of resolution (megapixels), the noise from P&S gets high at ISO 400 while on a DSLR, the noise is low to 800 or higher. At a minimum, for a hand held shot, you need a shutter speed 1/(lens focal length X sensor crop factor). So on a 10D with a crop factor of 1.6 and a 50mm lens, that would be 1/50 X 1.6 or 1/100 of a second. There are many tables available for suggested shutter speeds for various subjects. I suggest the Kodak Series: Ambient Light Photography.
Regards,
Scott

[maderito]

Start with your favorite ISO - typically 100 or 200.

Then while you're shooting you'll encounter one or more of the following as you adjust aperature and shutter speed to get the correct exposure:

- Not enough depth of field at the widest aperture consistent with a well exposed capture (assuming you're not already at the widest aperture) -> increase your ISO

- Image not sharp because of motion or camera shake despite fast shutter speed -> increase your ISO

- I'm liking that grainy look -> increae your ISO (and call Drisley)

- Can't see anything on the review LCD screen -> increase your ISO :P

Have fun and take a lot of shots -- this stuff becomes second nature after awhile.

[abel]

i often increase my iso when shooting concerts. low light photography. this particular shot was at iso 800 - f 2.0 - 1/125th

http://www.nitrocross.com/images/pad/2004-08-Aug/14aug04b.jpg

ive tried to stay around iso 800 and lower for this type of photography. i proly could have used iso 400 and slowed my shutter down just a tad...

[robertwgross]

You might try switching your camera to the green box setting and then take a look at the ISO value it sets automatically. Just a thought.

Only some Canon EOS cameras do that. Some do not.

---Bob Gross---

[timmyquest]

You might try switching your camera to the green box setting and then take a look at the ISO value it sets automatically. Just a thought.

Most would beg to differ. Those "smart" zones are actually quiet dumb in my opinion.

[CyberDyneSystems]

In fact I don't think any EOS camera auto adjusts ISO in the "green box" setting... if there is an exeption.. it would be the Rebel.. but I doubt it.

[Mitch]

Your first priority is to get the shot. Your second priority is to get the shot at the best quality settings possible in the circumstances.

My rule of thumb, for me, is to use ISO above 100 on a 10D only when I have no other choice in order to preserve the required the minimal shutter speed to get a sharp image (i.e., shutter speed = 1/focal length on a non-IS lens, or 1/60 on my 28-135 IS USM at any focal length) and to preserve the optimum f-stop to get an adequate DOF for good, sharp photos (usually f-stop range from 5.6 to 8.0 for head shots or waist shots). I feel very, very comfortable shooting all night at a reception with low light with up to ISO 400. I will shoot with ISO 800 if I have to on occasion, but I will avoid ISO 1600 like the plague under these conditions.

Rather than go to ISO 800 or 1600, I will pump up the flash power and/or get closer to the subject if I can in order to avoid 800 and 1600 and use a wider angle focal length to get the same shot.

Final note, L glass handles higher ISO settings much, much better than than non-L lenses. Keep that in mind.

I shot a wedding two weeks ago in a restaurant with very, very low light. It seemed like the restaurant used only Christmas tree lights and 60 watt bulbs. I was starting to panic when they said they had the lights turned up all the way. But, I set aside my trusty 28-135 and used the 17-40L f/4 FOR THE ENTIRE WEDDING! Lucky for me the dance floor area (which was also used for the ceremony) had a low, white ceiling and I was able to bounce great light from the ceiling using my 550EX. The dining area had very high, dark purple ceilings where I had to get close, pump up the manual power setting on the 550EX and not use any diffusers. I used ISO 400 all night and everything came out great.

[scottbergerphoto]

1D Mark II, ISO 1600, Hand Held:

http://www.pbase.com/image/31607976.jpg

http://www.pbase.com/image/31607975.jpg

Regards,
Scott

[robertwgross]

In fact I don't think any EOS camera auto adjusts ISO in the "green box" setting... if there is an exeption.. it would be the Rebel.. but I doubt it.

Actually, the Digital Rebel does that automatically. Page 50 in the manual.

---Bob Gross---

[maderito]

In fact I don't think any EOS camera auto adjusts ISO in the "green box" setting... if there is an exeption.. it would be the Rebel.. but I doubt it.

Actually, the Digital Rebel does that automatically. Page 50 in the manual.

---Bob Gross---

Actually, so does the 10D, Page 49. We're just ashamed to admit it. :)

[DocFrankenstein]

Start from the result you want to get:

You want the "best" image you can get - crip, no noise... etc... (unless you're doing some creative night pics)

So, you will have to find a tradeoff between the high graininess of the image and the shutter speed.

Ideally, you would get a really high shutter speed at any aperture at ISO 100. But if there's not enough light, you start to increase the aperture...

IE: I am in Av mode shooting my friends at a party. I compose a pic and at ISO 100 I get a reading of 1/10 seconds. If I shoot at ISO 100, the image would have lowest noise, BUT I will probably blur the image. I am shooting with my 50mm prime, so I know that I need about 1/40th of a second to get OK results. So I bump up the ISO to 400 and it gives me the desired 1/40th of a second.... That's the way I choose to shoot.

Scott (^^^) is more picky about the sharpness of the image, and he prefers to have 1/100th of a second for the 50mm prime. He'd increase the ISO another notch to 800. He'd trade a bit more noise for the desired shutter speed, but my image has more chances of being blurred.

It's what you prefer and it's about you being satisfied with your own images. Some experimentation and practice is required. After a while you're gonna know the minimal shutter speeds you need for different subjects and adjust accordingly.

Cheers

[Jesper]

Your first priority is to get the shot. Your second priority is to get the shot at the best quality settings possible in the circumstances.

My rule of thumb, for me, is to use ISO above 100 on a 10D only when I have no other choice in order to preserve the required the minimal shutter speed to get a sharp image (i.e., shutter speed = 1/focal length on a non-IS lens, or 1/60 on my 28-135 IS USM at any focal length) and to preserve the optimum f-stop to get an adequate DOF for good, sharp photos (usually f-stop range from 5.6 to 8.0 for head shots or waist shots). I feel very, very comfortable shooting all night at a reception with low light with up to ISO 400. I will shoot with ISO 800 if I have to on occasion, but I will avoid ISO 1600 like the plague under these conditions.

Rather than go to ISO 800 or 1600, I will pump up the flash power and/or get closer to the subject if I can in order to avoid 800 and 1600 and use a wider angle focal length to get the same shot.
I agree - my default setting on my 10D is ISO 100. I shoot almost all the time in Av mode. When the camera chooses a shutter speed that's really too slow for hand holding, I switch to ISO 200 or 400. I hardly ever use ISO 800 or 1600, I don't like the noise.

The best is ofcourse to use a faster lens (such as your 50 f/1.8) and larger apertures (smaller f-stop numbers) - this will allow you to keep a lower ISO setting (although the depth-of-field will be shallower). Also, with fast lenses the camera will focus in low light easier.

Final note, L glass handles higher ISO settings much, much better than than non-L lenses. Keep that in mind.
That's new to me. Is this just another myth about L glass or is this really true? Can you please explain?

[theoldmoose]

Final note, L glass handles higher ISO settings much, much better than than non-L lenses. Keep that in mind.
That's new to me. Is this just another myth about L glass or is this really true? Can you please explain?

Probably a side-effect of all those guys with non-L glass over-sharpening their photos. :lol:

Sharpening increases digital noise, if any, in the frame.

[Mitch]

Jesper:

I consistantly get a great deal more noise when I shoot with high ISO settings with my Canon 28-135 than when I shoot with my 17-40L or my 70-200L at the same settings. It's not a marginal call, but quite obvious. The L glass simply gives you a better image, all else being the same.

[Pekka]

Final note, L glass handles higher ISO settings much, much better than than non-L lenses. Keep that in mind.
That's new to me. Is this just another myth about L glass or is this really true? Can you please explain?

Probably a side-effect of all those guys with non-L glass over-sharpening their photos. :lol:

Sharpening increases digital noise, if any, in the frame.

May also be that L glass lets you use higher shutter speeds. ISO noise is partly dependent on shutter speed (slow = more noise).

[Pekka]

??? I know that it takes practice shooting under variable lighting and changing conditions, but is there a rule of thumb as to when or how much to increase the ISO setting? I shoot with a Canon 10d, 17-40L, 28-135 IS, and 50mm f1.8, mainly people :?.

Thanks in advance,
Jeff

The simplest rule of thumb I can come up with is "change ISO if changing shutter speed and aperture does not get results you want".

I choose always aperture first, then I check what shutter speed I can get - then I adjust ISO to get faster or slower speed. I usually go for higher ISO because I like very high shutter speeds as they give me better enlargements (the old shutter speed rule 1/(focal*crop factor) is for postcard size prints, if you go A3 you may need much more than that).

[Mitch]

Pekka wrote:
"the old shutter speed rule 1/(focal*crop factor"

Question out there...do you really have to multiply the focal length by the crop factor? From my interpretation of the geometry of the crop factor, I do not believe that it is necessary to multiply by the crop factor.

[DocFrankenstein]

Pekka wrote:
"the old shutter speed rule 1/(focal*crop factor"

Question out there...do you really have to multiply the focal length by the crop factor? From my interpretation of the geometry of the crop factor, I do not believe that it is necessary to multiply by the crop factor.
The FOV changes proportionally to the crop factor. The camera movements are amplified by the crop factor...

It makes sense...