Help me use my camera

Factual Questions
1

I have a Canon powershot SD800IS. I have used the camera for a few months now and have read the user manual, but there are a couple of things I could still use help with, and I’d like to know the principle behind some of the manual options:

The functions I have available seem to be:

Autofocus: evaluative, center weight avg, spot
Auto white balance: day, cloud, tungsten, florescent, florescent h, custom
exp.: -2 through +2
ISO: auto, hi, 80, 100, 200, 400, 800, 1600
macro: macro, regular, infinity
flash: off, auto, on always
also have some other things like scene modes and timer / multi shot, movie mode, and stability enhancement

In particular, it seems like I need an explanation of how to use the exp and ISO settings.

  1. Taking dim light pictures with movement - whether movement of the subject or just the motion of me not being able to hold the camera steady. I originally assumed that night mode would do this but instead it seems it just lets the picture expose longer than it normally would when using a flash, so that the background is still lit. Aquarium mode seems to work pretty well - the pictures come out fairly bright and the motion isn’t blurred, but it seems to also be compensating for what it think will be aquarium color ranges and so I have to adjust the colors later to be more natural. Is there a way to get this effect without the color compensation, just using ISO and exp?

  2. Taking pictures of stars. I’ve gone to where you can actually see the stars (Vermont), laid the camera on a flat surface, and tried various settings, but haven’t been able to get more than a picture of blackness with noise. I thought I read someone mention in some thread or user comment somewhere using a camera like mind and getting good night sky pics so I would think it’s possible, but I can’t figure it out.

  3. Taking pictures of spiders. Especially when not very close. It seems the camera can’t see the web, and has trouble focusing on the spider if it’s not taking up a large portion of the view. So it focuses on the background instead. I’ve discovered that if I use the macro mode instead of the macro setting this sometimes helps although not as much if I’m not that close. I would think changing the auto focus mode might help but I don’t properly understand them. And I can’t figure out if there is some way to manually focus.

  4. Changing focal length (?). Not sure if that is the proper term. I know there is some way in general (maybe not on my camera) to change the apparent size of the foreground versus the background. They do this in movies sometimes where the character comes to some horrible realization and while they stay the same size, the background suddenly becomes larger as a visual metaphor of their mental state. What is this called? Can I do it on my camera. I’d like to do things like take pictures of the full moon behind a tree and not have the moon look like a tiny circle.

Thanks!

2

dpreview.com is the place to go…

3

DPreview.com and DCResource.com are my two go-to photo sites.

I have the SD800 as well. Excellent choice. :slight_smile:

  1. Low light and movement - Everything you try is going to be a compromise. I would use Manual mode, set ISO to 200 or 400, turn off flash, and hope for the best. If you’re going to be using the modes night mode is OK, you may want to under expose slightly.

  2. Stars - Take a look at the Long Shutter option, make sure it’s turned on. Take a look at page 53 in the manual to learn how to use it.

  3. Macros of spiders - There’s no manual focus on this camera. Macro mode is your best bet, possibly using Focus Lock to get the subject in focus. You might try Spot focus and see if that helps.

  4. Focal length affects - you have no direct control over the aperture in this camera, and the effects you describe are mostly moving picture effects which you certainly can’t achieve. In general the smaller the aperture the shallower the depth of focus. This allows you to isolate your subject from the background and is very useful in portraits among other things. But very small size of the CCD combined with the short zoom range of this camera doesn’t give you much chance to take advantage of that. It’s very hard in P&S digital cameras without manual controls.

4

I think I know the effect you mean - where a person in the foreground stays he same size while the background objects get smaller/bigger? If you set the zoom to its widest (short focal length) and then walk towards your subject to frame them nicely, you will find the background objects appear to diminish quite quickly the farther back they are. Now set the zoom to the other extreme (telephoto or long focal length). Frame the subject the same way - you will need to walk back to get them filling the same area. You will notice that objects behind the subject do not diminish anything like as fast as at the wide setting. You have discovered one of the greatest creative controls in photography - it always pays to think about where you are standing as well as what zoom setting you are using.

What they have done here is to start with the zoom lens at a longer focal length then, whilst moving towards the subject, zoomed out to a shorter wider focal length. Harder to do in the movies because you need to coordinate moving the camera, zooming and re-focusing all at the same time without it getting jerky. I bet that in Hollywood they use some gizmo which does all three adjustments together.

Yes, set zoom to its longest focal length. Unfortunately the moon is a tiny circle :frowning: . Unless you have a very long range zoom the effect will not be so dramatic. Worth a try though.

Other things to try are photos of someone in a busy street. At the long setting they will appear to be hemmed in by a dense crowd, at the wide setting they will appear more separated from their surroundings.