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

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Sensor Cleaning with Sensor Swab, LensPen, and Blower

Hi everyone.  Sorry for the infrequent posting (our daughter has fever).

Anyway, I cleaned my camera's sensor for the first time with more than just a blower.  I resorted to a Sensor Swab with Eclipse fluid, a LensPen Sensor Klear and a blower.

I got the Sensor Swab and Eclipse fluid because it was recommended by the store where I bought my Nikon D600 (Bel-Air Camera).  Their service department uses blowers and this combination.  As for the Sensor Klear kit, I got it because I wanted a lighted loupe, and it came with a blower.  As for the LensPen SensorKlear itself, I thought it would be good to try because I find the LensPen effective for cleaning my lenses.

Here are the results.

Since this was my first time, I didn't dare try to clean my D600 and instead I practiced cleaning my Nikon D70.

This is what the sensor looked like at f/45 (I used a Tamron 70-300 VC).

Quite dirty, even though I couldn't see anything with the naked eye, or even with the lighted sensor loupe that was included in the SensorKlear Kit.

ATTEMPT #1: BLOWER
The first thing I tried was a blower.  I selected the menu option for raising the mirror, tilted the camera facing down at around 45 degrees, then used the blower at various angles to the sensor, being very careful not to touch the sensor/AA filter.  Here's the result.

A significant improvement, although not pristine.

ATTEMPT #2: LENSPEN SENSORKLEAR
When I first used the lighted sensor loupe from the SensorKlear kit, the light would not turn on despite having fresh batteries (the small ones similar to those used in watches -- be very careful to keep these away from babies).  I determined that it was because the battery contacts were loose.  I used a tweezer to pull them and make the contact with the battery tighter, and after that the light worked.

The lighted sensor loupe went over the camera mount.  The loupe has a cut away to allow you to put the lenspen in the mirror box and clean the sensor as you see it.  At first I liked this feature but after a few cleaning attempts, I found it easier to just clean the sensor without the loupe then use the loupe to inspect the sensor.  The other thing is that the magnification of the loupe is not super high.  I estimate perhaps 10x or so, and it seemed that whatever I could see in the loupe, I could almost always see with my naked eye with careful scrutiny.

Using the lenspen was easy.  The lenspen is similar to the one used for lenses except that it can be angled.  The tip is also triangular which I suppose helps clean edges of the sensor's rectangular surface better.

Here is the result.

Both of those shots were taken after the first attempt with the lenspen.  Terrible.  There were those huge specks that I believe came from the lenspen itself.  I thought maybe that's because it's the first time to use it.  So I gave it another shot.

I cleaned again with the lenspen, this time looking to see if the lenspen was itself introducing new spots.  Here is the result.

Ugh.  Better than the first attempt but no better than using the blower.  In addition you can see that there are strand-like specks.  I don't know if those came from the lenspen or were in the mirror box and released by the lenspen.

In general I found that the lenspen could clean the dust but somehow there would be new dust, or perhaps the old dust just got moved.  The dust wasn't getting absorbed by the lenspen.

ATTEMPT #3: SENSOR SWAB
This time I decided to try the Sensor Swab.  Each swab is individually wrapped in a clear plastic bag.  The swab is wrapped with some sort of lint-free artificial fabric which is secured to the swab with a small elastic rubber band.  The fabric and rubber band can be mistaken for a mere wrap -- do not remove them.

Sensor Swabs come in two sizes -- one for full frame and another for APS-C.  The one for APS-C can be used for full frame as well but it will take more than one swipe and is therefore not recommended.

I placed a drop of the Eclipse fluid on each side of the sensor swab.  Starting from one side of the sensor, I swept to the other side, then swept back using the other side of the swab.  I found it hard to make sure that the swab was making sufficient contact with the sensor without pressing too hard, especially near the corners.  In addition, the sides of the swab tended to get snagged by the frame around the sensor.

Here is the result after a couple of swabs (each swab is supposed to be used only once).

Better than the lenspen but still quite a few specks around the corners.

After a couple of attempts with the sensor swab, my D70 suddenly locked up.  All I could see was "CHA" or "CHR" where I normally see the shots remaining.  The camera could focus but would not take shots.  I recharged the battery and reformatted the CF card, and on the theory that perhaps the sensor got too wet, I left it to dry a bit.  I tried again and the D70 was working again.

Anyway, I tried to clean it a couple more times with the sensor swab (5 times total) but could not get rid of all the dust.  I thought maybe the lenspen would do a better job at the corner so I tried that again.

ATTEMPT #4: LENSPEN AGAIN

As with one of the previous shots, it seems the lenspen itself seems to lose some bits of fabric that end up as specks.  It could be that the lenspen is getting snagged by the sharp-edged frame around the sensor, causing it to lose those bits.

ATTEMPT #5: BLOWER AGAIN
I tried the blower again

Not perfect but much improved.

PRELIMINARY CONCLUSION
I'm a newbie at cleaning sensors but for now my preference is to simply use the blower.  If there are stubborn specks, I'll use the lenspen.  The lenspen may lose some bits but those are easy to blow away with the blower.  I'm wary of using the sensor swab.  It seems that it takes skill to use it very well and practicing with it is expensive.

Because of the blower's effectiveness I might also consider the Firefly ionizing blower, suggested to me by a reader (thanks!).  Update: Firefly review posted here: Firefly DSC-2000 Review

RELATED POSTS:
Firefly DSC-2000 Review

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Update on Nikon D600 Sensor Oil/Dust Spots Issue

One of the few issues about the Nikon D600 is its propensity to get dust on its sensor.  It has been documented by Roger Cicala of LensRentals here.  In addition, some say the sensor gets oil (not just dust) on its sensor.  Roger did not notice any oil on the 20 units of the D600 that he examined, and I personally have not observed it.

Anyhow at around 2000 shots I noticed that there were spots on my shots, even at a not-so-narrow aperture of f/8.  I blogged about that here.  I thought the spots were oil based on the characteristics I observed but it turned out that the spots were only dust.

That was about a month ago.  I'm now at around 4500 shots, and although I haven't seen dust on my shots, I decided to reexamine the sensor.  Here's what I found.



I now have a lighted sensor loupe, so I took a look at the sensor.  To my relief, I did not see anything that looked like oil spots.  I only saw a few flecks of dust.  I blew them using a sensor cleaning blower but some of the spots remained.  I tried to take photos of the sensor but it was really challenging.  Here's what I was able to capture:

Other than that one spot, I couldn't see much.  (I was able to blow that one spot away using the sensor blower).

Meanwhile I decided I would take some narrow aperture test shots.  At first I took shots at f/22 and didn't notice anything.  I then changed to a Tamron 70-300 VC which can go to as narrow as f/32 then I took a shot:

In Lightroom, I maximized the contrast to make the dust spots easier to see.

Click for higher-resolution versions of the shots.  It's a lot dustier than what I could see from the sensor loupe, but I'm not very worried because they aren't showing up on my shots.

ACTUAL EXAMPLES OF OIL
Sometimes, dust exhibits the characteristics of oil (see here) therefore dust can be mistaken for oil.  The following are definite indicators of oil:

1. Visible oil on sensor.  See this photo:
http://www.talkphotography.co.uk/forums/showthread.php?t=433703

2. Rings on test shots (dark outside, light inside).  If there is a ring but it is light outside and dark in the middle, the ring could just be a halo from excessive postprocessing (sharpening, clarity, contrast, etc.).
Example on D800 photo (scroll down):
http://nikonrumors.com/forum/topic.php?id=5517&page=7
Photos of REAL oil spots - courtesy of Canon.

Link 1: http://www.usa.canon.com/cusa/support/consumer?pageKeyCode=prdAdvDetail&docId=0901e0248013d2ea
Link 2: http://cpn.canon-europe.com/content/news/EOS_oil_spots.do

Note: the spots on my sensor don't seem to have donut-like rings like the ones shown on Canon's site.

3. If you physically attempt to wipe the dust and it smears.
WARNING: physical contact with the sensor or AA filter will void your Nikon warranty

11/16/12 UPDATE:  I just want to pose a question for readers: this issue about the D600 is very widely known.  And there is clear evidence of DUST.  However, even the issue about spots is very widely known and there's so much interest and discussion about it, why is it that there is still no unmistakable evidence of OIL (i.e. photos of actual oil spots on sensor/lowpass filter, or donut-shaped rings on photos, or smeared oil)?  There is evidence of oil on some other cameras (see examples) but I haven't seen any such evidence for the D600. Could it be that people are mistaking spots for oil?  Just something to think about.

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

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