How do I prioritize shutter speed in Powershot SD700IS - General Help and Assistance on using CHDK stable releases - CHDK Forum

How do I prioritize shutter speed in Powershot SD700IS

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How do I prioritize shutter speed in Powershot SD700IS
« on: 27 / February / 2011, 16:49:26 »
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Hello-

I do not know much about cameras but used CHDK to allow me to see how much battery I had left and it is wonderful.

I have another problem. I take pictures of swimming fish underwater and would like the camera to default to the fastest shutter speed that the camera's aperature and ISO setting allow for the existing amount of light.

How do I do this?

I see that there is something called Tv by which I can be set a particular shutter speed, but this is not what I want.

Is there a way that CHDK can solve my problem and prioritize shutter speed?

Thank you

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Offline SkyWalker9

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Re: How do I prioritize shutter speed in Powershot SD700IS
« Reply #1 on: 27 / February / 2011, 20:22:10 »
Hello-

I do not know much about cameras but used CHDK to allow me to see how much battery I had left and it is wonderful.

I have another problem. I take pictures of swimming fish underwater and would like the camera to default to the fastest shutter speed that the camera's aperature and ISO setting allow for the existing amount of light.

How do I do this?

I see that there is something called Tv by which I can be set a particular shutter speed, but this is not what I want.

Is there a way that CHDK can solve my problem and prioritize shutter speed?

Thank you
There hasn't been any response yet, so I'll try to help you. Since I don't have access to your model of camera, the only resources I have available are copies of the SD700 Basic Manual and the SD700 Advanced Users Manual. After reading both, here is what I think would be your best options:

1. The best option. Select SCN mode, choose the underwater setting, and start with the lowest ISO first. Avoid using the Auto ISO and ISO-HI since the Auto ISO will not allow you to adjust the ISO and the ISO-HI setting will result in the most noise in your photos.

Before taking a photo start with the lowest ISO setting (80), press the shutter halfway until you see what shutter speed the camera says it will need for the current light level. If it results indicate it needs more light, then try increasing the ISO to the next higher setting (100, 200, 400, 800 or ISO-HI as a last resort) and press the shutter halfway again to see if that helps. Keep repeating this sequence until you can shoot the photo. If you cannot adjust the ISO high enough, then you may need to use something like a monopod with your camera in low light situations and use a lower ISO.

The reason for choosing this method is that the SCN/Underwater setting will color compensate for the bluish cast of shooting underwater (this setting uses a built in white balance setting to compensate). See page 8 of your Basic Manual for more information on the setting. If the water you are shooting in isn't bluish, then you may have to fine tune/adjust the color on your computer later.

2. The next best option. Set the Manual mode setting (see page 7 of Basic Manual) and do the same things mentioned above. You may want to color compensate in post processing on your computer rather than attempt while shooting the underwater photos. My experience has been that many people don't attempt to color compensate until they have more experience adjusting in post processing.

I'd recommend trying both of these methods under normal circumstance first. Real world experience will avoid confusion when you are ready to shoot the underwater photos. Just choose a situation with low light like in your house in the afternoon, early morning or later in the afternoon near dusk.

Hope this helps...Good luck shooting!
« Last Edit: 27 / February / 2011, 20:51:46 by SkyWalker9 »

 

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