[Simon23]

I'm just wondering if someone who has owned or owns (god forbid) another brand of camera and how the noise around say iso-800 upwards in low light situation compare with other camera's in similar semi pro/price bracket?

Also how much does the roll of the lens play in the noise factor?

Cheers
Simon

[OregonJim]

Pentax is known for giving the USER control over noise. Rather than over-processing in-camera to remove noise (and produce smeared images), Pentax DSLRs let you dial in as much or as little noise reduction as you want, either in camera (for JPEG), or in PP (JPEG or RAW).

Therefore, comparing high ISO noise performance to other brands is highly dependent on camera settings and/or PP - by default, Pentax favors retaining image detail over removing noise.

[newarts]

....

Also how much does the roll of the lens play in the noise factor?

Noise is correlated with the of light collected during an exposure; the more light, the lower the fraction of noise.

Therefore lenses that can admit more light can give lower noise images for exposures of a particular length.

The few other sources of noise are not related to the lens and are most important when there's little light at all.

Iowa Dave

[bymy141]

If you read for instance the Digital Cameras, Digital Camera Reviews - The Imaging Resource! camera reviews, you will see how other cameras handle image noise.
Don't be fooled by apparent low noise on first sight, many camera's have noise reduction algorithms inside, removing noise at the cost of image detail.
Many photographers believe that they should be in control over noise reduction in post processing, so I advise you to study the RAW image examples best.

In general terms lenses do not add noise to an image.
However, lenses with a lower f number will be able to deliver more light to the sensor, making it possible to avoid higher ISO settings with the same light (at the cost of "depth of field").

Remember when you increase your ISO number, you will be amplifying the sensor signal more, before it is digitized. It is like turning up the volume. Any noise in the signal will be amplified with the image signal itself. Like with sound noise is more noticeable with low signals (dark parts of the image).

- Bert

[Simon23]

Cool, thanx guys! I've been doing a lot of live gigs lately and have been curious as to how well I am doing with my 17-70 2.8-4.5(is that a laugh I hear) but for some place's it works well others not so well.

I think you guys are right about having more control over the noise settings and find myself only tweaking it a little in pp to keep the sharpness and not get that yukky plastic look!

Here's my link to flickr if u wanna throw cc my way!

Flickr: simonbaker.photos' Photostream

[mattdm]

Therefore lenses that can admit more light can give lower noise images for exposures of a particular length.

Not by some sort of magic, though — this is what lower ISO is. If your lens doesn't have a wide enough aperture to admit enough light for the exposure at the given shutter speed, you have to increase the ISO, which results in more noise.

Here's an interesting read on digital camera noise:
The Online Photographer: Noise Is Your Friend

[OregonJim]

Here's my link to flickr if u wanna throw cc my way!

Flickr: simonbaker.photos' Photostream

I think you're doing a great job pushing that 17-70 to the limits...