View Single Post
Old January 12th, 2011, 10:44 AM
marko's Avatar
marko marko is offline
Administrator - Pet lover
Join Date: Mar 2001
Location: Montreal Quebec Canada
Posts: 12,062
Originally Posted by hazelrunpack View Post
This winter I've been trying to figure out the manual settings on the camera but I'm running into a problem with low natural light. The sun is, of course, low because of the season but it's also usually obscured by clouds and/or swirling snow, so the natural light has been extremely low.

I was hoping to get some shots of goldfinches taking off (we have 200 or so around lately and I thought it might make a neat pic when they all swirl up at once) but even with a fast shutter speed, I'm having trouble with the low light. Should I be monkeying with ISO at the same time?

I'm almost desperate enough for lighting that I'm considering putting the external flash (which I've never used ) to work.

(If it helps, I'm shooting a Nikon D90.)
It DOES help to name the camera you are using - and it IS good enough to get the shot you want. Because birds are EVEN MORE jittery than cats and dogs klmccallum has learned the correct answer here Shutter priority indeed! For birds, I would choose 1/500 or faster as my shutterspeed.

If the light is too low to accommodate that speed when you look through the viewfinder, It will say Lo. At that point you can raise the ISO. On your camera, I'd suggest ISO 1000 might be the maximum you can use before you see noise or graininess. IF at ISO 1000 and at a shutterspeed of 1/500 it still says LO - there's nothing you can do except wait for brighter light, add flash, or jack up the ISO even higher and live with the graininess.

In the intro thread, i mentioned that exposure is the balance of ISO, aperture and shutterspeed. It works as a mathematical formula that's not complex at all. here's just one example: let's say for this bird shot your settings are this:

ISO 200 F5.6 at 1/60

As mentioned 1/60 is too slow for birds. If you RAISE The ISO you make the sensor MORE sensitive to the light coming in. So if you raise the ISO from ISO 200 to 400, You'll need to change the shutterspeed to 1/125 (or something close). OR you'll need to change the aperture to F8. THIS IS WHEN YOUR CAMERA IS SET ON MANUAL.

When your camera is set on shutter priority the camera will do the compensation for you. Sooo if you input 1/60 and the ISO is at 200, the camera might give you F4 depending on the light available. If you raise the ISO by 1 unit to 400, the camera will change the aperture by 1 unit to F2.8 (It won't change the shutter speed in shutter priority because shutter speed is the variable set by YOU.) Just to be EXTRA clear F4 was the original hole, aperture or F-stop...but because you raised the ISO, we compensate with a SMALLER hole of F5.6 because the film sensor got more sensitive by 1 unit. Even though mathematically it makes no sense, it works. F-4 lets in 2x more light (or 1 full unit) than F-5.6

(Aperture numbers (the F-stop or the hole) can be confusing to newbies UNTIL you think of them as FRACTIONS. F-4 is a larger hole than F-5.6 Just think of it as a fraction and it makes perfect sense. Would you rather have 1/4th of a pie or an 1/5.6th of a pie? A 1/4 is the larger piece. F-5.6 is a larger hole.)

If you dial in 1/500 and the F-stop says Lo, try raising the iso by 1 "unit" or 2 units to see if you can get an aperture that does not say Lo.

Here are how the "units" work when they are in 'full conventional units" Your new digital camera can use units in between these standard units, but the compensation will always be the same. This means that if you change by 1/3rd of any of these "units" the camera will compensate by changing something else by 1/3rd to balance the exposure. This is when you are in a fully automatic mode or a semi automatic mode like shutter priority or aperture priority.

ISO - 100 (slow ISO speed) - 200 - 400 - 800 - 1600 - 3200 - 6400
S.S. - 1sec - 1/2sec - 1/4 - 1/8 - 1/15 - 1/30 - 1/60 - 1/125 - 1/250 - 1/500 - 1/1000 etc
F - F32 (small hole - think of it as a fraction) - F22 - F16 - F11 - F-8 - F5.6 - F4 - F2.8 - F2.0 (large hole) etc

Hope this helps and please let's investigate further if it does not.
Thx - Marko
Please tactfully EDUCATE or IGNORE posters you don't agree with.
Please PM me & Include URLs and post #'s for any issues and it's my pleasure to help.
I'm firm - but fair. Mind the Rules and enjoy your stay.
Newcomers FAQ - How do I post on this BB?
Pet facebook group
Check out the Pet podcast
Follow me on Twitter

Last edited by marko; January 12th, 2011 at 04:12 PM.
Reply With Quote