Camera Labs

Since I've recently brought a fast 50mm f1.8 and I've been messing with the narrow DOF. This has resulted in VERY fast shutter speeds.

Are there any problems caused at the sensor by extreme shutter speeds.

I seem to remember with film that the chemicals needed a certain amount of time to react.

I think I've read that with very long exposures heat can build up in the sensor causing increased noise. Has anyone got any information as to when this can start to happen.

Likewise are there any effects at the sensor caused by exposures at the other end of the scale and the maximum shutter speed my camera is capable of 1/4000?

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Canon EOS 550D (with Magic Lantern)
18mm - 135mm Kit Lens, 50mm f1.8, Sigma 30mm f/1.4 EX DC HSM
430EX II Flash with Phottix Strato Wireless Tigger Set
Manfrotto 190CXPRO3 with 496 Ball Head. Gorilla Pod SLR
Canon Powershot A720IS with CHDK and intervalometer script. Pentax Optio W90

My Blog - http://www.ianganderton.wordpress.com

Don't think there are any issues!

I hope not, anyway! f1.4 and I'm bouncing off 1/8000th when the sun's out

In the days of film, that was something to be concerned about. With extremely quick shutter speeds, the film plane just wouldn't be exposed to light for enough time for the film to react. This was also the case with long exposures, making astrophotography very inconvenient as, for example, a 1 minute exposure didn't behave as a 1 minute exposure should behave. There were ways to get around this that required lots of effort, but we don't need to worry about that with digital, that issue doesn't occur anymore.

Regarding long exposure noise, I believe (but not 100% sure) that you'll probably see more noise with a longer exposure, but nothing to worry about, you'll get more noise with a shorter exposure end a higher ISO (for example, you'd get more noise with a 15 second exposure at ISO 800 than a 30 second exposure at ISO 400).

Hope that I helped!

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-Evan

Gear: 7 Nikon Nikkor AI-S and AF-S lenses, SB-700 flash, Nikon D7000, Nikon FM, variety of accessories

"There are no rules for good photographs, there are only good photographs."
- Ansel Adams

Long exposure noise, you're looking in the magnitude of seconds and longer when you might start to notice hot pixels showing up from it.

I'm not aware of any fast exposure issues providing you have enough light.

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Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

How many seconds Popo? 30? 60? 600?

I'm interested in developing my skyscape skills. I took this the other day


https://picasaweb.google.com/lh/photo/5T3DYxR0Fz3O5FbrDkSOKdHMI7Yuh5O-Envau5-75DM?full-exif=true

ISO 3200
Exposure 30.0 sec
Aperture 4.5
Focal Length 18mm

Its a very high ISO and I'm trying to work out the best way to improve the in camera photo recipe including noise reduction

_________________
Canon EOS 550D (with Magic Lantern)
18mm - 135mm Kit Lens, 50mm f1.8, Sigma 30mm f/1.4 EX DC HSM
430EX II Flash with Phottix Strato Wireless Tigger Set
Manfrotto 190CXPRO3 with 496 Ball Head. Gorilla Pod SLR
Canon Powershot A720IS with CHDK and intervalometer script. Pentax Optio W90

My Blog - http://www.ianganderton.wordpress.com

You might start to notice hot pixels showing up from long exposure as short as a few seconds. The longer, the more there may be. On the plus side, most modern raw converters will get rid of them for you. Even without using raw, the number you get e.g. from camera jpeg isn't that bad so I can manually clean them easily enough.

Older generation sensors were much worse though.

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Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.