Dust... Sensor or Lens ?

[elrafo]

Hi everyone !

Thanks to your advice, I manage to modify the SWC and put the CFV16, works like a charm !
my only concern is the spots I found in the image, actually quite a few.

these black spots are VERY visible when I get in close focus with f22. this is a test i did for short range focusing area.

I spent a long time wiping and cleaning the sensor but still, I can see these spots... any idea if this could be on the Lens instead ?

https://www.dropbox.com/s/a1o8zuqmg4vifdw/A1217842.jpg?dl=0

 

[kdphotography]

They look like dust spots on the sensor. Do the spots move after cleaning? I'd try a different sensor cleaning method....

ken

 

[GrahamWelland]

Sensor dust.

 

[jng]

I agree with Ken and Graham. Here's another diagnostic: do the spots become more diffuse and/or disappear altogether when you shoot at larger apertures? If so, these are almost certain to be dust spots (or just spots) on the sensor/sensor cover glass.

John

 

[pflower]

Shoot a clear sky or uniform white wall - slightly underexposed at your widest and again at the smallest aperture. If they remain uniform at both then it is probably something else but if there are differences and (as suggested they disappear completely or mostly at the widest aperture) then it is probably dust. The one thing that suggests against dust is that zooming in on your jpeg there are clearly dust spots there but not where you have put arrows. What you have identified seem uniform in size and shape and sharp. Not what I experience with dust. Also digital backs on old V systems can be difficult to get right - I would certainly suggest that you clean out the body of the camera with compressed air since it is likely that the body itself has some dust in it. I was appalled when I first used a CFV-50c back on an older 503 that the entire sensor was covered in dust on a shoot rendering everything virtually useless. Cleaning out the camera helped me as did multiple cleans of the back with e-wipes (although these should be used carefully since they can leave streaks).

Those with better understanding of optics than I will no doubt be able to advise better, but if it was a problem with the lens I question whether it would result in such well defined and sharp spots. I would examine the sensor carefully under a bright light and with a loupe or magnifying glass and see what you can spot on it.

Good luck.

I agree with Ken and Graham. Here's another diagnostic: do the spots become more diffuse and/or disappear altogether when you shoot at larger apertures? If so, these are almost certain to be dust spots (or just spots) on the sensor/sensor cover glass.

John

 

[GrahamWelland]

A further review of the picture reveals to me that you've got a very dusty sensor. Good advise here about making sure that the camera body is clean too to prevent getting it dirtier, although you could argue that an SWC should essentially be a sealed unit once the back is on it.

If the issue was optical I'd be very surprised if you would be able to see any artifacts at all. Heck you could have a cracked lens and it would be tough to tell in reality as the results are normally so diffuse.

I do see a few hot pixels but they are literally individual pixel size and distinct. The black blobs though look every bit like dust on the IR cover glass. Could be under too btw but unless the filter has been off I'd be surprised if that was the case.

I have a Leica Monochrom that had a dust issue that wouldn't clean up successfully despite several clean ups using wipes / sensor swipes and in the end I was able to clean it perfectly using a sensor gel stick - that was a first for me. Sometimes wipes and static charge can just end up moving the dust around. Also, definitely use a sensor loupe to side illuminate and view the cover glass for dust - try using a fresh rocket blower (I swear by the new VisibleDust Zeeion blower as it only blows clean uncharged air).

 

[TimG]

How did you clean the sensor?

If you're using a ped-pad + eclipse cleaning fluid, it should get most stuff off,

 

[elrafo]

I have been using sony lens cleaning e Wipes ... and some dust off. but the Spots are still here, I think they might be behind the IR filter ...

How did you clean the sensor?

If you're using a ped-pad + eclipse cleaning fluid, it should get most stuff off,

 

[elrafo]

sensor gel stick might be a solution indeed as the EWipe didn't work out, I need to check this option ! thanks !

A further review of the picture reveals to me that you've got a very dusty sensor. Good advise here about making sure that the camera body is clean too to prevent getting it dirtier, although you could argue that an SWC should essentially be a sealed unit once the back is on it.

If the issue was optical I'd be very surprised if you would be able to see any artifacts at all. Heck you could have a cracked lens and it would be tough to tell in reality as the results are normally so diffuse.

I do see a few hot pixels but they are literally individual pixel size and distinct. The black blobs though look every bit like dust on the IR cover glass. Could be under too btw but unless the filter has been off I'd be surprised if that was the case.

I have a Leica Monochrom that had a dust issue that wouldn't clean up successfully despite several clean ups using wipes / sensor swipes and in the end I was able to clean it perfectly using a sensor gel stick - that was a first for me. Sometimes wipes and static charge can just end up moving the dust around. Also, definitely use a sensor loupe to side illuminate and view the cover glass for dust - try using a fresh rocket blower (I swear by the new VisibleDust Zeeion blower as it only blows clean uncharged air).

 

[Wayne Fox]

I have been using sony lens cleaning e Wipes ... and some dust off. but the Spots are still here, I think they might be behind the IR filter ...

dust off is pretty risky. Other than a rocket blower using any type of pressurized gas can damage the sensor glass.

As far as on lens or sensor, you never see small defined spots from dust on a lens. Normally you can’t even see dust on a lens, unless it’s the back element of a really wide lens and it has some pretty large chunks on it but this manifests itself as large blobs. Dust on a lens can cause loss of contrast and in some cases cause soft focus look, but won’t show items like the image.

It’s pretty rare to get dust under the IR filter, but I suppose it is possible. might want to review some good videos on wet cleaning a sensor and see what happens.

 

[tcdeveau]

sensor gel stick might be a solution indeed as the EWipe didn't work out, I need to check this option ! thanks !

I started using a sensor gel stick recently and think they're pretty magical. Just make sure to follow the directions and don't apply too much pressure.

 

[ErikKaffehr]

Hi,

Somewhat reluctantly, I bought a sensor loupe from Visible Dust. It really shows dust and specs on the sensor.

It can be a good way to see what kind of spots they are.

Best regards
Erik