Flats and Dust Motes

[Starwiz]

Here's a stretched image of the master flat for the red filter created using 30 flats in DSS.

The dust mote I've highlighted is still visible in the Red image I've stacked when I stretch the image.  I've used 30x flats, 30x dark flats, 30x darks and 40x lights.

So, the dust mote isn't being fully cancelled out by the flats in DSS.  Does this mean there is something wrong with my flats, or could it be something else?

Thanks

John

[Adam1234]

Could you post a picture of your stacked and calibrated red image? And details of how you took the flats?

[Starwiz]

15 minutes ago, Adam1234 said:

Could you post a picture of your stacked and calibrated red image? And details of how you took the flats?

To take the flats, I used the Flats Aid in DSS.  For the light, I used 3 white pillowcases and a Yaufey A3 Copy Board.

Thanks.