Compensating for Available Light with High ISO?

[kirbym2]

I've asked about ISO before, but want to clarify. If I'm aiming for a SS of 1/250, and available light just isn't cutting it, should I be cranking ISO to make the shutter speed work? Should I be looking to slightly overexpose to combat noise? What are your thoughts on this.

Shooting indoors, not 100% confident with my flash skills - may try it out off-camera, but would like a fall back. Just want to make sure I'm not going to end up with excessively noisy shots. I know my camera model can go quite high (for ISO), just not sure if there's an accepted peak limit (ie. 1600, 3200, etc).

Anticipating this challenge, I'm currently working with LR3.4 and CS5... any noise reduction tips would be greatly appreciated.

Thanks!

 

[tirediron]

Your options are: Increase the ISO (will potentially increase noise in the image), use a larger aperture if possible (will decrease DoF), or add more light (flash/strobe). The highest usable ISO varies by camera and user preference. Spend some time experimenting and find out where you feel your camera reaches its peak. As for exposure, I am a firm believer in always shooting for the correct exposure.

 

[Scuba]

I think the d7000 has very good noise ratings. You should be good up to 3200. Only advice I can add for noise is reduce it before sharpening so you don't sharpen the noise and make it more obvious. Still best thing to do is test out your ISO rating first and see if it is acceptable to you.

 

[Big Mike]

There are three primary factors to determine your exposure. The shutter speed, the lens aperture and the ISO.

If you choose to use a certain shutter speed (1/250 for example), then you will have to adjust the other settings until you reach settings for proper exposure. The first thing you're likely to change, is the lens aperture. But you may soon reach the maximum aperture of your lens, so your next step is to change the ISO.

Shooting indoors, is usually a rather dark scenario. So it's likely that in order to use a fast shutter speed like 1/250, you will need to use a higher ISO.
And yes, using a higher ISO will mean more digital noise in your photos. The amount of noise is something that is different from one camera to another. Also, people's tolerance of noise is different. You may be OK with the noise you get at ISO 800 with your camera, but someone else may not be. So you should do some experimenting to find what your comfort levels are.

Of course, another alternative would be to get a lens with a larger maximum aperture, thus allowing you to get your exposure without having to go so high with the ISO.

And yes another alternative would be to add more light...using flash for example.

As for dealing with noise, Lightroom and Photoshop do have good tools for reducing noise. I'm sure a google search will turn up plenty of useful links.

Should I be looking to slightly overexpose to combat noise?

In most situations, you will see less noise if you do slightly overexpose...but in this example, you would have to raise the ISO higher to get that overexposure...so that would negate the benefits. But if you use the shutter speed or aperture to increase your exposure, then you could slightly expose to help control noise...but be aware that the aperture also controls DOF and the shutter speed controls how motion is captured. In other words, don't use too slow of a shutter speed, giving you blur, just so that you can control noise.

 

[MLeeK]

I'd venture to guess you can use images all of the way to the MAX ISO on your camera-IF YOU EXPOSE FOR IT. Yes, that means slightly over. I'd expect your D7000 to handle ISO about equal to my 7D or better and I can use 12800 on the 7D with a light noise removal in raw processing.

 

[Village Idiot]

There are three primary factors to determine your exposure. The shutter speed, the lens aperture and the ISO.

Oh no! The exposure police will be after you!

 

[kirbym2]

Thanks for the replies - feeling a little more confident about bumping my ISO up a bit. I'm thinking a line or two over (on my meter) from dead centre might be okay? I've looked at tutorials/manuals on noise reduction in LR, and played around a bit - I find that my images end up looking noise free, but also look quite processed.

Any low cost solutions for a program/plugin that might work well at addressing noise? I use a Mac, so would have to be Mac friendly.

Thanks!

 

[kirbym2]

Didn't think to put in a piece about aperture. I'll be using a 50mm 1.4, but would like to stop down a little to benefit from max sharpness on the lens. Would you guys rather go wide open and a lower iso, and hope for a couple of good shots, or would you stop down to say f4, up the iso a bit, and deal with the noise?

 

[Village Idiot]

Thanks for the replies - feeling a little more confident about bumping my ISO up a bit. I'm thinking a line or two over (on my meter) from dead centre might be okay? I've looked at tutorials/manuals on noise reduction in LR, and played around a bit - I find that my images end up looking noise free, but also look quite processed.

Any low cost solutions for a program/plugin that might work well at addressing noise? I use a Mac, so would have to be Mac friendly.

Thanks!

I was using Imagenomic's Noiseware until the screwed the pooch on the 64bit plugin.

A good trick is to use full tile noise reduction on a separate frame and pull the opacity back to get the desired look.

 

[KmH]

As you increase the ISO nailing the exposure when yoy release the shutter gets more and more critical.

This line is scary;

I'm thinking a line or two over (on my meter) from dead centre might be okay?

unless you understand what each of those lines represent.

If your camera's light meter is still set to the default meter settings, each of those lines is 1/3 of a stop.

A full stop is a doubling or a halving, times 2, or divide by 2. Full stops of shutter speed that let the image sensor see light for half as much time would be 1/100 to 1/200, 1/250 to 1/500, 1/10 to 1/20, 1/50 to 1/100, 1/2000 to 1/4000.

For ISO, ISO 800 is twice as sensitive to light as ISO 400. ISO 3200 is twice as sensitive and ISO 1600.

Lens aperture is a little less straight forward becuas we are doubeling the AREA of the lens aperture, not the diameter of the lens apertutre. Consequently, we have to use the square root of 2 - 1.4142 to calculate a full stop.
So, f/1 to f/1.4 is a full stop.
F/5.6 to f/8 is a full stop.
F/1.4 to f/2 is a full stop.
F/1.8 to f/3.5 is a full stop.

If you are using strobed light, a shutter speed of 1/250 doesn't let much available light in. Make the shutter speed longer, say 1/100, or 1/60 to have more available light recorded in the shot.

 

[kirbym2]

If you are using strobed light, a shutter speed of 1/250 doesn't let much available light in. Make the shutter speed longer, say 1/100, or 1/60 to have more available light recorded in the shot.

Do you think 1/100 or 1/60 is enough to get a sharp picture without the benefit of a tripod? If so, I think I'd be happy to decrease my shutter speed, so that I wouldn't have to compensate as much with ISO.

In your opinion, with a higher iso, should I be looking for my camera meter to be bang on for exposure (not slightly overexposed)?

Thanks!

 

[KmH]

When using strobed light, the short duration of the flash of light stops motion, not the shutter speed.

If you're using strobed light, you don't need to use a high ISO either.

If you're using strobed light, ignore the in-camera light meter.

 

[Scuba]

I don't remember seeing what you are going to be shooting? Stills or motion? I would say a 1/125 would certainly be plenty to avoid motion blur/camera movement on a still object.

 

[kirbym2]

This is for a newborn shoot. In confirming with the mom, sounds as though the room is quite bright, with a large bay window. This presents a different challenge. They're looking for some shots with a black background. I'll keep the baby close to the window - how far back should I position my backdrop from the subject - Do you think 5 feet is sufficient?

Thanks for all the great advice!

 

[altitude604]

http://www.dofmaster.com/dofjs.html

here you go.