How does sensor dirt show up?

[Martin Beek]

Hi all.

I have all kinds of sensor cleaning stuff (and procedures) in my kit, but i'm too scared to use them on my Scarlet sensor. I don't even dare to have a look at the sensor through my Visible Dust loupe. I change lenses Scarlet looking down, frantically and quick avoiding any dust to swirl in.
So, call me a dustophobe. ;-)

Now, i know of people who never check their Epic or Scarlet gate and change lenses all the time, not worrying too much about sensor dust.

IF there is any kind of contamination on the sensor, how does this show up in the actual picture - when shooting 4K? Any examples available?

Thanks,

Martin

[Robino_J]

From what I know you can't touch the sensor as it is located behind the OLP glass filter... you can go ahead and clean it with proper cleaning tools.

[Mark Deeble]

It is very rare to get dust on the sensor itself,most of the time it is on the OLPF, which is sealed from the sensor by a flexible dust-proof bushing. Dust appears as slightly out of focus dots on the image - particularly noticeable if you open the iris and point the lens at a uniform bright subject like the sky. Racking the lens from infinity to MOD should make no difference to the focus on the dust.
Best removed using a swab or an 'arctic butterfly'.

[Russ Fill]

Mark I think you mean to stop down the iris to say f 11 or 16, 22 you will see dust if its there when you point the camera at a consistent light colored back ground.. Like a white wall or as Mark explained a no cloud sky. Try to expose properly,,, not blown out or even slightly under exposed, using the iso or shutter speed and if there is dust you will see it in the form of small dark points. If you have your lens at say f 3.5 or 5.6 it will be very hard to see due to the fact that it will most likely be almost to soft to see. Also when you take the clip in to say RCX you will want to blow it up to see the dust and areas. Remember the image on the sensor is reversed to what you are looking at on the computer, so a pice of dust will be in the opposite place you see on the computer screen to on the sensor. This is what your loope is for.
And yes you wont be touching the sensor, it is covered by the OLPF filter and as long as you are careful you should be good to go. I don't usually use swabs or other cleaners if I can help it. A hand ball blower will usually do the trick.
Anyway I use to be afraid of messing up the sensor also but after some time looking in to the chamber and asking around you will feel comfortable cleaning your sensor if you need to but honestly, the Epic has been the one camera I have owned that has almost no dust to mention. I don't know what kind of magic is in that chamber but what ever it is it works.

[Phil Bates]

I have been shooting a lot of sky plates lately with my Epic and it seems that about one out of every 20 lens changes or so we will see a dust speck on the sensor. I am usually shooting around f14 or so and at f-stop the dust looks like a fuzzy spot slightly darker than the rest of the sky. As Russ said, a quick puff of air will usually do the trick.

Phil