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Hi All,

Just wondering if anyone has tested the built in NR on the higher iso levels with the d70 and the results? Is it worthwhile enabling when you know you are going to be shooting high iso levels? Will the NR only work on jpegs?

Obviously the feature slows down continuous shooting, so that would be a time when you may not use the feature

Chris

A far as I know the built in NR on the D70 is a subtraction only.
That is, it is designed to remove artefacts rather than supress random noise

To clarify on MHD's point - the noise reduction feature is for long exposure, not high ISO noise.

It makes a difference for multiple minute exposures to remove the purple tint in the frame's top left hand corner, due to CCD heat build up interferrence, but also introduces its own artifacts making it not all that much more useful for star trails and delicate detail photography.

I have tried it in the past for night shots, didn't notice an optical difference but did notice the 30-60 second processing time before saving. Not for continuous shooting, unless the items are buildings and your camera is on a tripod

Glen wrote:I have tried it in the past for night shots, didn't notice an optical difference but did notice the 30-60 second processing time before saving. Not for continuous shooting, unless the items are buildings and your camera is on a tripod

Are you shooting continously with speed 1 sec or more? (1 sec or longer is speed when NR starts working)

What it does, is another shot without opening shutter to make a pattern of environmental noise (warm, light through viewfinder etc.) and then removing artefacts comparing this pattern with previous shot. So, if your speed was 30 sec, it will process NR for 30 sec as well. If speed was 1 sec, it will run it for 1 sec.

Hi Mikhail, it was at Lavender Bay and shots were around 30 secs, so that explains the processing time. I didn't realise the second shot was at the same exposure length as the first. Thanks

No Mikhail, joke about continuous shooting, I tend to think NR and continuous are incompatible.

NR turned on will actually halve your frame rate at any speed in my experience, whether it's working or not.

IE I turned it on and for ages thought the camera rather slow in continuous, even at shutter speeds well under 1 second. Turned it off upon suggestion (Onyx's I think) and the camera was back up to it's proper speed again.

I'm having it on and off ocassionaly and don't feel any difference when shooting with speed less than a second

Just did 40 continuous shots in one batch with NR "ON". No stopping, no slowing down. Then did the same with NR "OFF". No difference

Hlop wrote:Just did 40 continuous shots in one batch with NR "ON". No stopping, no slowing down. Then did the same with NR "OFF". No difference

What image size /quality you have it on? try RAW, i bet it changes....

I waited about 5-10 minutes for NR to work its stuff whenI took a 10 minute exposure....it didn't do much

Click wrote:What image size /quality you have it on? try RAW, i bet it changes....

Don't bet - you'll loose I shoot RAW only. Never tried JPEG

PiroStitch wrote:I waited about 5-10 minutes for NR to work its stuff whenI took a 10 minute exposure....it didn't do much

As mentioned before, it fires CCD up without curtain opening to get pattern of environmental noise. 1. It takes the same time as exposure. 2. If there is no much noise, it won't do much

The NR frame is an equal length exposure to the light frame, we astronomers call it a dark frame. The idea is to reproduce an equivalent amount of thermal "noise" in the CCD and subtract it from the light frame, in theory leaving just the information from the light hitting the CCD (ignoring dust shadows,vignetting etc for the purposes of this discussion). It is only applicable to longer exposures as there is neglibible "dark current" in short exposures. The noise is greatly reduced at lower temperatures, which is why the CCD camera I am using now is running at -102C!

Gordon