I just purchased a new OM-1 Mark II camera (late August 2026). I recently noticed what looked like dust on my sensor in some of my images - there were dark circles in the same location in many photos with a light background and not much detail. Today I took a test photo to verify my strobes were working so I was not focused on anything at all. When I reviewed my photos I noticed the "dust" looked like small circles in a pattern. At first I thought the circles might somehow be on the subject I was shooting, but when I reviewed my photos I shot on my next dive I saw this same pattern of circles in some of my images that had a light, blurry background.

I took a number of photos above the water when I was evaluating the camera but I never saw these circles, even after thoroughly re-reviewing the image.

I have been shooting with a 90mm lens in the AOI housing, with the FLP-08 port. I am also shooting with the 60mm lens and so far I haven't seen these circles in a pattern with the 60, but I have seen the dark spots in like dust on the sensor.

Has anyone else experienced this problem?

Edited September 23Sep 23 by TropicLeslie

Did you follow the recommendations by, e.g., dustpatrol for making the test photos above the water?

The dots look indeed like dust, bvery likely the sensor needs cleaning...

@TropicLeslie I agree that it seems like dust spots. They can be quite common on mirrorless sensors.

To start, thoroughly clean both your lenses. This is key! (I use Zeiss disposable lens wipes.)

Then test the sensor by photoing a light colored wall out of the housing and review the image(s) for dark spots. Dust spots are often not visible in dark areas of the photo. Repeat this with both of your lenses.

If you see the same dots using both lenses it is most likely dust on your sensor. Carefully clean the sensor with a manual bulb dust blower such a Giottos Rocket, but do not use canned air, a power blower, or similar. High powered air can damage the sensor.

If the dots are not seen, place the camera back in the housing then repeat the test with both lenses to check the port.

The goal is to find the origination of the spots by a systematic process of elimination and then resolve the issue.

Good luck!

chip

At first I thought it was dust, but when I took a look at the test photo (blue/lavendar abstract image) I thought the spots looked more like outlined circles forming a pattern, not random dark spots like I have typically seen indicating dust on the sensor. I will try and clean the sensor and let you know the results. Thx for the reply!!! 😁

Yep, dust spots on the sensor.

As Chip suggests, photograph a white wall with the lens out of focus. They’ll show up clearly.

Good luck with the sensor clean. I found it a bit nerve-racking first time I had to do it. It can take 2-3 attempts. Steady patience and a clean swab for each attempt. There are cleaning swabs available for specific sensor sizes. 1-2 drops of sensor cleaner on the swab then gentle left to right motion across the sensor. I can recommend PecPads as the covering for the swab.

They do indeed look like dust Dust can be highly variable in the way it appears based upon the lens and f-stop being used. I currrently have a dust spot on my sensor of my old ME-1 MkII. Here it is at f22 (300mm lens):

and the same area at f4:

and here at f8 with the 90mm macro:

You can see that it is much less noticeable at wide apertures, the worst lens I came across for highlighting dust was the MP-e 65 Canon lens - it could do up to 5x and at that magnification every speck of dust was sharply defined. This speck seems to be something sticky that got blown in when the lens was off, I tried cleaning it but it doesn't want to move. Just look at the RH spot, the LH spot is a darker area on the wall.

Olympus sensors are usually very good at staying clean, they have a vibration system to shake off dust and it it is mostly extremely effective, but if a liquid spray or something sticky like some pollens get on they can cement on. You do need to be careful cleaning OM sensors as they float the the sensor for IBIS and the mechanism can be damaged unless you park the sensor. Your pattern looks like very small liquid droplets or mist has hit the sensor, based upon the pattern of dots.