Showing posts with label ISO. Show all posts
Showing posts with label ISO. Show all posts

Tuesday, September 21, 2010

So you want Low Noise at High ISO



Hey Gang! Glad to see you're back. I'm not entirely sure what the image above has to do with high ISO and low noise... It was shot with a D300 in studio conditions at ISO200. I wanted to share this shot with you all though. It's my friend Heather, who after a horrific traffic accident used Yoga to regain mobility. She's an inspiration to anyone who has to overcome an obstacle.

On to some high ISO low noise goodness! I had a friend on twitter(by the way if you're not following on twitter, why not? it's @reddoorphoto)ask me about the noise capabilities of the D700 because he was considering buying a new camera and wanted better noise reduction/capabilities. I asked him if he had thought about a D300s instead. At half the price, it comes really close to the quality of the D700 in the noise department, plus it shoots video! To prove this to him I set out to do a little experiment... More on that after the jump:



We had an engagement session last night, so I took the opportunity to grab Shad's D300s and his D700 and do a quick, unscientific test. Same lens, same ISO(3200)spot metered off of the guys back in the shadows. Take a look at the results:

ISO comparison

To view it larger click HERE

The D700 is on the left, D300s on the right. I Spot metered for the back of his shirt that was in the shadows, so the background is blown, but that's ok. You can see the noise(what little there is) on the zoomed in section. I think the D300s file looks as good, or better than the D700 file. I'm pretty sure that both are perfectly acceptable. Is there a $1300 difference between the D300s and the D700? I don't think so. Unless you need the full frame for an ultra wide lens like the Sigma 10-24 FX, I can't see a justification to go with the D700 instead of the D300s. This was of course a real world test, not a scientific laboratory test, but the proof is in the image above. What do you think? Let me know in the comments below.

Thanks for stopping by, see you next time! Jason

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Saturday, February 7, 2009

Controlling Flash




This is my Wife Dawn on her Birthday last year. The combination of the day at the spa, and having her makeup done professionally made it a whole lot easier to photograph her. I really love the way her skin looks so smooth, and the beautiful wood background that allows for good separation from her hair.

Today we're going to talk a little about flash control. It took me a long time to get my head wrapped around this concept. We are taught that shutter speed, aperture, and ISO are all parts of exposure. The setting of one, effects the setting of the other. If you lower your aperture, you raise your shutter speed and vice verse. Now throw all of that out the window when you talk about flash. The only thing that controls the flash is aperture. When you are trying to get the exposure right when using flash, you have to decide first what your cameras flash sync speed is. This is the highest shutter speed that the camera can sync with the flash. Most modern digital cameras sync at 1/250 of a sec. This is important because this is the shutter speed that you want to set if you want to use strictly flash for your image, and no ambient light. So to go about this you would set your camera to manual. Set your shutter speed to 1/250 of a second. Start your aperture at f/5.6 and take a test shot. Look at your histogram and see if the exposure is correct. With your flash set to TTL the flash will adjust the output to compensate to make the exposure correct. If by chance the ambient light is too bright for the flash to compensate, the highlights will be blown and you will see it on the histogram. If this happens, you will have to adjust your aperture. The higher the aperture, the less flash that is allowed in. Using the example talked about above, if the image is overexposed with the aperture set to f/5.6 you will have to move your aperture up to f/8. The higher the aperture, the less light allowed in.

Ok, so now you have the aperture set right, the image is exposed correctly, but the background just falls to black past the subject. What to do now? You have to let more ambient light in. The way to do this is to lower the shutter speed. You would go from 1/250 to 1/200. The slower the shutter speed, the more ambient light that will be allowed in. The best way to figure this all out is to try it. Set the shutter speed, set the aperture, and take a picture. Look at your histogram to see if the exposure is correct. Play with the settings, until you get the look you're after. I hope this helps you understand what goes into flash exposure. Have a good weekend. See you all Monday. Jason Read more on this article...