In low light do you favor ISO or Shutter?

[Matt S]

Yesterday I had the opportunity to photograph a momma bear and cubs. I burned up 150 pics before they headed off into the woods. The light forced me to shoot at 1600 ISO and (due to slow glass) shutters around 125 if I was lucky. As you can imagine my ratio of keepers to trash is not real high due to camera shake and motion of the subjects. So hear is my question. In low light (wildlife photography) do you pick the slowest shutter you can get away with to favor ISO or do you crank up the ISO to get maximum shutter speed?

I will post bear pics when I get a few more processed and loaded up on my website.

 

[ckdamascus]

Well, it's really hard to stabilize at long focal lengths in low light, so I would bump the ISO, then as a last resort, go with the shutter speed. I already consider pushing the ISO a serious compromise, so I just bring a tripod with me.

You could buy a faster lens, but it is usually very expensive to buy a lens fast enough to give you enough stops.

For instance, my kit lens is at f/3.5-4.5 so getting an f/2.8 zoom would still give me only 1.33 stops. Or in other words, I could go from ISO 1600 to ISO 640ish or so. Or I could change my shutter speed from 1/125 to 1/250. (big whoop).

A tripod would avoid most of the problem altogether but at the price of weight and inconvenience.

 

[Matt S]

Thanks Carroll, I agree on the tripod, and typically take one along. However this time I was in boat not much larger than your average canoe with two other people. One of them my 7 year old son who can't sit still. So the tripod was not feasable. I suppose your correct about ISO. What good is less noise when you sacrificed so much shutter speed that all your pics are blurry. I do have question for you though. What would you consider the minimum shutter speed (on tripod) for a moving subject?Assuming of course that you are not trying to blurr motion.

Sadly I think the real answer is fast glass

BTW: Some of the photos are posted in the animals forum now

 

[Steved53]

Matt,

It depends on how fast your subject is moving. It also depends on the focal length of your lens and whether or not you have VR on that lens.

The old rule (with regard to handholding) of maintaining at least as high a shutter speed as the focal length of the lens is good to stick with, with an adjustment for digital. So, before, the rule was if you had say a 200mm lens, you needed at least 200th of a sec. to try and ensure shake free photos. With the multiplication factor of digital, that should probably go to 300th of a sec.

My view is that if you have a shutter speed around that, you shouldn't really worry about subject movement - assuming it isn't a Gazelle or something similar!


However, if you had on let's say a 50mm lens (brave man!). You should be looking towards a 75th of a sec. shutter speed to stop camera movement. This is unlikely to be sufficient to stop subject motion unless it is just a slow amble. The fast movement of a group of little bears would need something around say 200th of a sec. to be pretty sure of stopping the motion.

These are just rules of thumb, and many people are able to effectively control their own movement and take adequately sharp photos with a 50mm lens, at much less than a 75th of a sec. But if the subject moves, what is the point?

So, it is a little more complex than just saying such and such a speed is o.k. In less than ideal lighting conditions you need to bump up the ISO and/or use a fast lens and/or use a tripod and/or use flash. Each of these choices introduces potential compromises that have to be managed.

In the difficult conditions that you mention, my experience is that your percentage of keepers will inevitably be quite low. You just have to decide what you can realistically do at the time, to try and increase that percentage.

 

[Matt S]

Thanks Steve, I was using a 70-300 at the 300 end and max shutter around 125, so I was definatly pushing the limits for sharp photos. I too use the inverse of the focal lenth to determine minimum hand hold speed. I find with my slow glass, F6 at 300, that I rarely am so lucky to have shutter speeds that high.

 

[ckdamascus]

Looks like he nailed all the points down before I could!

If you are on a boat, supposedly you need even faster shutter speeds. I too subscribe to the rule of thumb of 1/focallength, and sadly with the Nikon APS sensor, it has to be 1/(focallength*(1.5)).

Sniffles.

I guess we just need the D2HS at High Iso with a 300mm f/2.8 or D2X with NoiseNinja at High Iso with a 300mm f/2.8 lens then you can crop it down.

Total cost....... well that's just too scary for me to calculate. You might actually tip the boat over from the weight of that gear.

 

[Ken-L]

I usually let the camera choose the ISO and shutter for me. I'm less concerned with shutter since I started using the VR lenses. For most of my shooting it works well.

I'm counting on the VR of both my lenses to help with shots from boats soon when I go on an Alaska cruise (and helicopter, pontoon plane, steam locomotive, and dogsled!).

 

[Matt S]

VR.......OH Sweet VR......... Someday Ken, Someday I will have them.
Have fun on your cruise. 8)

 

[JayR]

I agree that a tripod (or a monopod) makes a big difference and takes care of most of the problem.

I tend to use lower ISO for static subjects and bump the ISO for moving subjects in low light to gain shutter speeds of atleast 1/125 or 1/250.

 

[greyflash]

I pretty much favor keeping the ISO as low as I can. When I shot film I did much the same using and ASA of 50 much of the time. Tripods are essential much of the time with low ISO although with care you can still be succesful without it. Case in point is the interior shots of Cathederals in Italy on my web site. You will notice that I was shooting at 1/2 to 1/10 of a second much of the time and without a tripod. Bracing on walls, posts, trees, etc., is a good way to go at it.

 

[Bill]

If a tripod is not available, than it really depends on what you are trying to achieve. For example, if you need a lot of depth of field, than you choose a higher ISO and a slower shutter speed. The opposite may be needed if you need a tight shot with little depth of field. It any case, it is fun to experiment and shot as much as you can.

Bill