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Dust spots
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Feb 25, 2021 12:54:22   #
Mileagemaker Loc: Jackson NJ
 
Using a Nikon Z-50 with a Nikor 18-300 lens. With a circular polarizing filter getting dust spots at f-10 and up. Under f-10 pictures are fine. Have cleaned the sensor, lens and filter. Still same results. Without the filter gain 2 f stops to f 13 with good results. Over f 13 see dust spots.

Feb 25, 2021 13:04:44   #
CHG_CANON Loc: the Windy City
 
We'd need to see an example image to set a common understanding and basis for discussion. From your description and apertures, these sound like run-of-the-mill sensor dust. When you say you've cleaned the sensor, how and what tool(s) did you use? When you reviewed test images during the cleaning process, how small of an aperture did you use and were the dust spots confirmed as being removed?

Feb 25, 2021 13:10:55   #
rmalarz Loc: Tempe, Arizona
 
I concur with our colleague, CHG_CANON. The smaller f/stops will bring out dirt spots. The polarized light might help do that at a larger f/stop.
--Bob
Mileagemaker wrote:
Using a Nikon Z-50 with a Nikor 18-300 lens. With a circular polarizing filter getting dust spots at f-10 and up. Under f-10 pictures are fine. Have cleaned the sensor, lens and filter. Still same results. Without the filter gain 2 f stops to f 13 with good results. Over f 13 see dust spots.

 
 
Feb 25, 2021 13:15:38   #
amfoto1 Loc: San Jose, Calif. USA
 
The smaller the lens aperture, the more obvious any dust on your sensor will be. There's still dust on there even when a large lens aperture is used, but they are more blurred in images and tend to be "hidden".

I don't know why a circular polarizer would make dust more obvious. Probably due to increased contrast and reduced reflections in images for it to "hide" in.

One of the "problems" with most mirrorless cameras is that their sensor is exposed when the lens is removed. It's also fairly far forward in the camera body. In a DSLR, it's deeper in the body and hidden and "protected" behind a closed shutter, which in turn is behind the mirror.

Some manufacturers are starting to design their mirrorless to close the shutter and protect the sensor, whenever the lens is removed. I know Canon has done this with their more recent full frame mirrorless R6 and R5 models. I don't know if any of the Nikon Z do this, but would hope all manufacturers begin to build this feature into their mirrorless.

So mirrorless are more "prone" to gathering dust. Even if you never remove the lens, most lenses move air in and out of the camera body and can transfer dust in the process. You'll likely need to clean the sensor more often than you would have with a DSLR.

A few things that might help...

1. Minimize lens changes and particularly try to avoid doing them in dusty situations. If you remove the lens for storage, promptly use a body cap on the camera and a rear lens cap on the lens to minimize dust gathering on them.

2. Be sure to leave any sensor self-cleaning cycle enabled. Many cameras now have that and automatically run the self-cleaning cycle each time they're turned on or off.

3. Do a thorough, careful cleaning and as a last step use a "sensor pen" to gently "polish" the surface. Other sensor cleaning steps frequently leave a little bit of haze on the surface that allows dust to "attach". The sensor pen polishing removes that haze and makes it quite a bit more resistant to dust getting stuck on the sensor and helps the automatic cleaning be more effective. (Note: In case you don't know, it's actually a protective filter in front of the sensor where the dust is gathering and that you're cleaning.)

Good info on sensor cleaning can be found here: http://www.cleaningdigitalcameras.com/ Note that often a "wet" cleaning is needed to remove oils from the surface. Shutter lubricants, most likely... Or finger oils if you accidentally touch the sensor. Those oils in particular can cause dust to adhere to the sensor so that the self-cleaning cycle, which vibrates the sensor to "shake off" dust, won't remove it. Also note that if oils are on the surface, it's important to remove them before using other steps and methods of cleaning, because any oils will contaminate things like sensor cleaning brushes and sensor pens, ruining them.

EDIT: By the way, cleaning the lens and filter will likely be of no help. Dust on either of them will not show in images. (In DSLRs, the same is true of cleaning the mirror and/or focus screen.... will have no effect on dust showing up in images.) Dust on lenses and filters can cause additional flare effects and a lot of dust can affect resolution... But it's very unlikely to be defined enough in images that you'll actually see specks on (or in) either lens or filter. It has to be something surprisingly large on (or in) a lens or filter to actually show up in images.

Feb 25, 2021 17:29:30   #
IDguy Loc: Idaho
 
So far I’ve been able to keep my Z6 and Z50 sensors clean with a combination of in-camera dust off (Z6 only), rocket blower, and Arctic Butterfly (static brush). The sensor closer to opening seems the help the rocket blower.

If the Z50 gets a stubborn one you can wet clean. Nikon is negative on wet cleaning Z6 because IBIS is fragile.

Feb 25, 2021 17:32:29   #
IDguy Loc: Idaho
 
amfoto1 wrote:



2. Be sure to leave any sensor self-cleaning cycle enabled. Many cameras now have that and automatically run the self-cleaning cycle each time they're turned on or off..


Unfortunately the auto cleaning function on my Z6 has never worked. I manually initiate from time to time.

Feb 25, 2021 18:08:39   #
Mileagemaker Loc: Jackson NJ
 
I spoke with Nikon and they suggest only air blaster. I bought an Altura lens cleaning kit which includes an air blaster, 2 brushes one of which is the pencil type and cleaning cloth. There is no liquid cleaner in this kit. I have tried the two different types of brushes, one of which is the pencil and the air blaster. It is better but still get dust spots at f 14 without a polarizing filter. Thank you so much for all of your help.

 
 
Feb 25, 2021 18:08:50   #
joer Loc: Northern Illinois
 
Mileagemaker wrote:
Using a Nikon Z-50 with a Nikor 18-300 lens. With a circular polarizing filter getting dust spots at f-10 and up. Under f-10 pictures are fine. Have cleaned the sensor, lens and filter. Still same results. Without the filter gain 2 f stops to f 13 with good results. Over f 13 see dust spots.


The debris on the lens and filter will not show up as dust specs in your image. The polarizer just increased the contrast making the dust more noticeable.

You didn't clean the sensor well enough. Dust is more visible at high F-stops. Your options are: clean the sensor more thoroughly, remove the dust in post or shoot below the f-stop threshold.

Feb 25, 2021 18:15:14   #
CHG_CANON Loc: the Windy City
 
Mileagemaker wrote:
I spoke with Nikon and they suggest only air blaster. I bought an Altura lens cleaning kit which includes an air blaster, 2 brushes one of which is the pencil type and cleaning cloth. There is no liquid cleaner in this kit. I have tried the two different types of brushes, one of which is the pencil and the air blaster. It is better but still get dust spots at f 14 without a polarizing filter. Thank you so much for all of your help.


When I google "Altura lens cleaning kit", I'm not seeing the appropriate tools to clean your sensor. This discussion would still be helped if we can see an actual image example. You can get wet cleaning kits, but most people can clean a sensor with just a Giotto Rocket-Air, such as this example: An exercise in sensor cleaning

Feb 26, 2021 17:31:43   #
parmruss
 
I used a wet-cleaning kit on my D7100 recently, and had to use two swabs in succession to get rid of some stubborn spots. Creating a white test photo before and after really helps to confirm your cleaning.

Feb 26, 2021 18:49:40   #
Mileagemaker Loc: Jackson NJ
 
The Althea kit was purchased from Amazon and contains a soft brush. A pencil brush, magic fiber microfiber cloths and a rocket blaster. I even tried a wet wipe. I will try to send a picture as well. Once again, thank you so much for your help.

 
 
Feb 26, 2021 19:15:41   #
Mileagemaker Loc: Jackson NJ
 
correction--Altura Kit. Trying to send a picture. Easier to send to an email if possible. Picture shows about 4 small dust spots taken on a Nikor 18-300 lens at 18mm cropped camera. Pictures smaller than F13 are good with no polarizing lens.

Feb 26, 2021 19:21:16   #
Mileagemaker Loc: Jackson NJ
 
Hopefully attached picture

Feb 26, 2021 19:26:56   #
Mileagemaker Loc: Jackson NJ
 
One more try.

Feb 26, 2021 19:39:13   #
Mileagemaker Loc: Jackson NJ
 
Picture attached shows several dark dust spots. Have to enlarge it to see dust spots. Tried everything from rocket blaster to wet wipes. Tried at least 6 times. It is better but dark dust spots still show. Using a 18-300 Nikor lens with a Z-50 Mirrorless.



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