D100 pixel problem

[zaxh81]

Hi all,
below is a night scene taken recently,100% cropped.
Camera is D100 with 18-70mm,F8 at 8sec.
It shows up blue dots,may i know what is it?
Dots won't show up on my D70 with same setting.

[zaxh81]

sorry but ISO might be set to 1600 by accident
i have no way of checking the ISO,does high ISO cause the dots to appear?
Newbie here,take it easy on me.

[litefoot]

Originally Posted by zaxh81 sorry but ISO might be set to 1600 by accident i have no way of checking the ISO,does high ISO cause the dots to appear? Newbie here,take it easy on me.

Noise due to high ISO, just like grain. Turn your NR on.

[zaxh81]

Originally Posted by litefoot Noise due to high ISO, just like grain. Turn your NR on.

Thanks litefoot,
The problem is D70 NR off,not a single blue dot,D100 NR off,so many blue dots.
If i set to on,the camera will take much a longer time to write into the card.

[gundugundu]

I think its not just because of high ISO setting. You might be having hot pixels on your camera CCD. This is usually caused by doing too much long exposure shots. You can send it to Nikon service centre for a reset. I had this similar problem before & I sent it in for a reset & problem solved.

[litefoot]

Originally Posted by gundugundu I think its not just because of high ISO setting. You might be having hot pixels on your camera CCD. This is usually caused by doing too much long exposure shots. You can send it to Nikon service centre for a reset. I had this similar problem before & I sent it in for a reset & problem solved.

Thanks for pointing out

I thought hot pixels are inherent? I did not know it can be reset.

[rebbot]

Originally Posted by litefoot Thanks for pointing out I thought hot pixels are inherent? I did not know it can be reset.

hot pixels can be resolved by remapping.

[espn]

Just set NR on, it will rid it.

The hot pixels are caused by electronics, heat. The colours get stuck after a long while because of the electronics & electricity. There's no need to re-map.

NR will cause the buffer to drop as time is taken to reduce the noise over time, based on the 4 buffer for NEFs available, once NR is on, you lose half the buffer for D100.

Hope this helps. Cheers.

[alechim]

what you can do is on your camera only when you wanna do the long exposure shot..I had this problem with my D100, so I off my camera and on it only when i am ready to take the shot..

[zaxh81]

Originally Posted by espn Just set NR on, it will rid it. The hot pixels are caused by electronics, heat. The colours get stuck after a long while because of the electronics & electricity. There's no need to re-map. NR will cause the buffer to drop as time is taken to reduce the noise over time, based on the 4 buffer for NEFs available, once NR is on, you lose half the buffer for D100.

Thanks espn,now i understand the theory behind this hot pixel thing.
But if i am to shoot fireworks,which i tried with the D70 with NR on,there will be some waiting time.
Some important night shot will be lost.
Remapping doesn't seem worth it,just need to shoot with my D70 more now.

Originally Posted by alechim what you can do is on your camera only when you wanna do the long exposure shot..I had this problem with my D100, so I off my camera and on it only when i am ready to take the shot..

Hi alechim,are you referring to on the NR when i want to take long exposure and off it when i'm done?

[espn]

Originally Posted by zaxh81 Thanks espn,now i understand the theory behind this hot pixel thing. But if i am to shoot fireworks,which i tried with the D70 with NR on,there will be some waiting time. Some important night shot will be lost. Remapping doesn't seem worth it,just need to shoot with my D70 more now.

Like mentioned, hot pixels are caused by prolonged usage + static electricity around the sensor

Actually when shooting @ ISO200 (for D70/D100) a pro once advised me that there's no need to turn the NR on. For the last fireworks festival, I didn't use NR on my ex-D100, I had no problems with the blue dots as there's only like 1 or 2 only. So I maintained my buffer of 4 NEFs and fast writing time with uncompressed RAW so I had no problems catching the fireworks.

NR definitely will take a longer time.

[alechim]

Originally Posted by zaxh81 Thanks espn,now i understand the theory behind this hot pixel thing. But if i am to shoot fireworks,which i tried with the D70 with NR on,there will be some waiting time. Some important night shot will be lost. Remapping doesn't seem worth it,just need to shoot with my D70 more now. Hi alechim,are you referring to on the NR when i want to take long exposure and off it when i'm done?

I had NR on all the time

[zaxh81]

ok,thanks espn and alechim.

[espn]

Originally Posted by alechim I had NR on all the time

I didn't, switched it off

[Luval]

Originally Posted by alechim I had NR on all the time

No need to..