Long exposure noise with Nikon D800

<p>I have been taking some 3 and 4 minute exposures recently and have noticed lots of tiny light dots all over darker areas of sky,it seems to show mostly with exposures of 30secs or more. I never had to use long exposure noise reduction before with my D700 with similar times. Whats the thoughts on this,using long exposure noise reduction as you know doubles every exposure time. Maybe a firmware update? or just treble the resolution may be more problematic.</p>

<p>What ISO are you using?</p>

<p>Bob asked the right question, I think.</p>

<p>James Symington offers a file made at ISO 100 and about f/8 for two minutes in the thread at the link below. The link to the actual shot can be found near the bottom of his opening post. Once one follows that link, there is a link to the full-sized original file at the top of the page:</p>

<p><a href="../nikon-camera-forum/00aTM6"><strong>[LINK]</strong></a><br /> <br /> It sure looks clean at two minutes. What it would look like at three or four minutes is another question. I see no mention of noise reduction.</p>

<p><br /> --Lannie<strong><br /></strong></p>

<p>I've only used Sony and Panasonic cameras with the long exposure noise reduction and it works well. It works by taking a second exposure with the shutter closed and removing the pixels that show up bright on the dark exposure. I use it when ever I don't need continuity in my exposures. But when I need a continuous set, for example when getting shots to combine for startrails, you can't afford to lose half the time for noise reduction so I do it as well as I can post production. Staying at ISO 100 helps a lot, but at 3-4 min. your inevitably going to get some noise.</p>

<p>Sorry,I forgot to put the obvious 100 iso, They would not show in black and white the same as colour,quite a few forums are commenting on this problem. Nikons response seems to be use the long exposure noise reduction.</p>

<p>If Nikon recommends using LENR and it corrects the issue, I guess you should use LENR. Or fix it during PP.</p>

<blockquote>

<p>"...have noticed lots of tiny light dots all over darker areas of sky..."</p>

</blockquote>

<p>If it's digital noise (hot pixels, chroma noise, etc.) then it should manifest over the entire image, not just the darker areas of the sky. Without seeing an example image, and assuming clear skies, it's possible your camera is 'seeing' stars your eyes don't.</p>

<p>If you're getting digital noise from long exposures, you could try keeping the camera switched off until you're ready to make the exposure, and switch it off afterward to keep noise-inducing heat from building up in the sensor.</p>

<p>Otherwise, it's pretty much what Elliott said.To me, the 3-4 minutes the camera takes to do the dark frame subtraction LENR for a single exposure image is probably less time that it would take to fix it in post. YMMV.</p>

<p>Almost any camera will have bias issues on exposures that long. LENR addresses that simply and effectively. The camera will take a second image of the same duration with the shutter closed and subtract it from the image and that takes care of any of the long term bias effects. If you don't use it, you should. </p>

 

<p>I guess if you cannot afford the 'down-time' whilst the Dark-Frame is being taken, for a meteor shower maybe, just get another D800 and use them out-of-sync........:-)</p>