Low-light with a 30D

[leon_schnell]

Reality often demands that we have to make do with less-than-ideal

circumstances, and I've found that I'm having to photograph stage performances

in poorer-than-average lighting with a Canon 30D and a slow (f5.6 when at full

zoom) 28-90mm non-IS Canon lens. Using a tripod creatively I manage to take the

shutter speed down to 1/15s at maximum zoom, but mostly don't go below 1/60s at

f/5.6 (with the faster-moving acts). My question is what ISO should I use, in

combination with how much lightening in Photoshop, to minimise noise?

 

Because I'm mostly not using the photographs above regular print size I'm

comfortable using ISO 1600, but I'm wondering whether I'll get less noise if I

instead shoot at ISO 800 (i.e. under-expose by 1 stop), and then lighten the

image by 1 stop in Photoshop? The sad truth with the lighting though is that my

photographs at 1600 ISO are already under-exposed by about 1 stop, so the real

question is this: are ISO 800 photos lightened two stops in Photoshop, less

noisy than ISO 1600 photos that have to be lightened only one stop in Photoshop?

 

Thanks for any help!

 

PS: Yes, I know I could find this out in tests by myself, but I also want to

see if anybody else has also struggled with this problem.

[martijn_houtman]

Read about 'exposure to the right'. It basically means: overexpose until the histogram is at

the maximum right point (without clipping!), so that you can later bring down the exposure

to a normal level. This is because digital camera sensors introduce more noise in the later

stops (shadows). Don't ask me for the details :)

[zacker]

Id look into getting a good fast lens with IS... or even a good fast prime.. it will be a huge help. that coupled with a higher ISO and a tripod should work wonders for ya. the 70-200 f2.8 IS comes to mind.. it would definetly be a worth while investment.. also check out the ..17-85 (?) f2.8 IS lens.

[mark u]

There's a much better solution: get a 50mm f/1.8. It's cheap, optically much better than the junky 28-90 film kit lens (trade it - you won't miss it), and will allow you to shoot at higher shutter speeds with proper exposure, and probably at 800 ISO as well, though if the action gets fast paced, use 1600 and post process with proper noise reduction software such as Noise Ninja or Noiseware. If you also need more reach, add the 100mm f/2 or 85mm f/1.8 as a next step.

[jason_hall4]

I have not read the other post but...NO!

 

Yes, 800 ISO may have less noise when exposed properly, however underexposing increases noise a great deal and then to raise the levels in post processing is an absolute no no. You are asking for trouble. The shadow areas will be terrible.

 

The best solution is what Mark points out. A nice fast prime lens. If you get the 50 f1.8, it does ok at 1.8, but really shines at f2.2 and higher.

 

Jason

[tom l]

If your stage productions include dance, you will need a faster shutter speed to adequately capture the action - note you don't have to stop it frozen in time, a little motion blur on the extremities can make a nice effect but the face typically should be sharp.

 

I've been shooting doing a number of low-light stage shows (dance & theater) with reasonable results even at high ISO. I will shoot ISO 800, 1600 & 3200 without much concern. Shoot to properly expose the face and highlights (white shirts are the worst) which means your camera may indicate significant underexposure since most of the scene could be dark but in reality you will be getting a good exposure on the subject which is what counts.

 

When I started I had two slow zooms f3.5/5.6 and they were horrible. The next lens I got was an 85mm f1.8. Low price in comparison to zooms and a really sharp picture with good reach. Not good for fitting the whole stage in view but really nice for mid to tight shots. Each year following I added a new lens, 24-70 L f2.8 and then 70-200 f2.8 L (no IS). Expensive but well worth it. I still use the 85mm for certain shots and really dark conditions.

 

As mentioned, I don't worry about the ISO so much - especially when most people order 5x7's. I use NoiseNinja on the original image, then downsize to 5x7 and then sharpen. Usually this creates a virutally noise free image.

 

HTH

 

Tom

[alan_myers]

Hi Leon,

 

You really need a faster lens. It could be a prime, or an f2.8 zoom that will give you two additional stops in the situations you describe.

 

I shoot at 1600 when I have to with my 30Ds, and have made as large as 13x19 prints from some images. I leave in-camera noise reduction set to "auto" all the time, but I don't think it has much or any effect since I shoot RAW almost all the time.

 

The single most critical thing is to avoid under-exposure at all costs. That increases noise a lot. So, no, you absolutely do not want to try to recover two full stops from ISO 800 shots, if you are already having noise issues with ISO 1600 shots that are approx. one stop under-exposed. Err toward slight over-exposure.

 

If shooting RAW, you can also reduce the effect of noise during RAW conversions by setting Chroma Noise Reduction high, but Luminance Noise Reduction low... At least you can with Canon DPP. If the exposure is correct, not under-exposed especially, the Chroma (colored) noise seems to be converted to Luminance (B&W) noise, which is much less obvious and problematic, it sort of looks like some film grain, but no where near as prominent as it would be in actual ISO 1600 film.

[colinsouthern]

"It basically means: overexpose until the histogram is at the maximum right point (without clipping!), so that you can later bring down the exposure to a normal level. This is because digital camera sensors introduce more noise in the later stops (shadows)."

 

Martijn,

 

It's excellent theory - but the ability to apply it in practise depends on the circumstances. In this situation (unfortunately) the settings that would expose to the right with the lowest noise would result in VERY low shutter speeds and bucketloads of motion blur.

 

Cheers,

 

Colin

[JDMvW]

Set the ISO to H (3200) and try it. As an old film user, I don't find the results unacceptable on my 20D and the 30D is supposed to do a little better even. Maybe you won't find the noise too bad either.

 

The advice about getting the 50mm f/1.8 is good, regardless. Also consider the 85mm f/1.8 or even the 100mm f/2 if you need more reach. They're not such bargains as the plastic fantastic, but they are way less than buying zooms that are fast (but no more than f/2.8, at that).

 

Of course, the various f/1.2 L primes (50mm, 85mm) are sweet, but a little more costly. But if you need the speed, you have to pay the price.