Thursday, February 7, 2013

D600 Dust-Spot Drama: Low Tech Sensor Cleaning

And so the Nikon D600 dust spot drama continues....

Last weekend, I had to take photos at f/32.  As a result, spots that normally don't show up in my shots did show up.  However, I was able to clean them using a very low tech way.  Before I talk about the method, here are the results (click to get a high-res version):

BEFORE CLEANING
See the hair-like strand on the top left corner and the new speck in the middle of the upper left quadrant:

AFTER LOW-TECH CLEANING:

Note: both shots have had clarity boosted to 100% and other Lightroom adjustments to make the spots easier to see.

NOTE: Please ignore the EXIF.  I was using a totally manual lens which had a maximum aperture of f/5.6 so that's what the manual lens database stamped on the EXIF.  I was actually at f/32 for both shots.

Hit the jump to see what method I used :)


RECAP
First, a quick recap of the previous episode of Dustgate: at 6300+ shots, I reinspected my sensor.  The hair-like speck that I saw at 5700+ shots was still there.  I tried to use the blower several times but the speck wouldn't go away.  But since I didn't see that bothersome speck until f/16 and I normally shoot at f/8 or wider, I didn't care about it.

SHOOTING AT F/32
Well, last Saturday, I had a legitimate need to shoot at f/32.  So that speck that I ignored was showing up in my shot.  Not only that, it was joined by a new speck.  I was forced to deal with the spots.

The good thing though was that because of the new speck I now knew which corner had the hair-like speck which I still couldn't see with the sensor loupe.  As before I tried the blower several times.  To no avail.  The two specks were still there.  The big one moved a bit but that was it.  It was annoying because they looked like they weren't really stuck there, just held there through static electricity or something.  I thought about getting a Firefly blower (FYI I did try a small ionizer but it didn't seem to do anything).

But after thinking a bit, I decided to try a new tactic: a cotton swab (aka cotton buds or ear buds).  Not any special cotton swab.  Just the regular cotton swab used for our kids.  If you look closely at the cotton swab, you'll see that it has fibers extending from its head.  My hypothesis was that I could use those stray fibers (not the head itself) to snag these stubborn specks.  So I tried that.

I held the cotton swab very close to the specks but not touching it, then rotated the swabs, trying to get the loose fibers to get the specks.  Guess what.  It worked.

But ah, what about those fibers?  Surely some would get loose and create problems of their own?  Indeed there were a couple of new fibers that were now on the sensor.  And they were much longer than the specks I removed.  But precisely because of their size, those fibers were very easily blown away by the blower! :D

So, I traded a difficult problem for an easy one, solving both in the process.  Here is the shot again, after using the swab and using the blower (normal clarity level).



I'm not a hardware expert, so I don't know if there are any disadvantages to this method, or if I just lucked out this time around.  For example I would be careful not to go too near the sharp metal edge around the sensor because they could snag some of the fibers and they might be hard to remove then.  But otherwise it's probably something I will consider trying again next time I can't blow away a stubborn speck.

BTW, you may be wondering why I was shooting at f/32 and what was I doing with a totally manual lens.  That will be the subject of another post next time.

RELATED POSTS:
Nikon D600 Resource Page (see the topic Nikon D600 Dust Spots)
Firefly DSC-2000 Review