Dirt on sensor
 

I was out shooting again today, just some random stuff nearby from some windmills, and when I just saw the footage at home the dirt spot I had in my casino video appeared again on the same place in the bright parts of the sky. Only this time I had the stocklens on and at the casino shoot I had my primes on. I checked the lens and couldn't see anything, then I checked the sensor and at first I didn't see anything either but from certain angles then it looked like there was a very tiny spot visible but you could hardly see it. I used a small pump with a brush that my wife has to clean her lenses and blew some air at the sensor and did another shot of the sky and rechecked and the spot was gone.

Never had this issue with my dslr but that sensor is much better protected, it seems you need to be real carefull when changing lenses and double check with the loupe (I didn't have the loupe with me again as I thought the "spot" problem was solved.)

If anyone that doesn't have this camera yet and plans to buy, if you want some raw footage from what I shot today, just pm me your email address and I"ll send a wetransfer link.

Re: Dirt on sensor
 

ugh, just found out the sensor if full of spots, I shot a grey sky again and underexposed as much as possible and then several spots started to appear like ufo's.

My wife also has a Arctic Butterfly sensor brush but she not home right now and I couldn't find the brush, will clean this evening and see what that gives.

Re: Dirt on sensor
 

In the Sony Manual they actually tell you to tilt the camera forward not upward when changing lenses, I presume so any dirt is less likely to fall on an inclined surface. An old building like the casino must have a bit of airborne dust that gets kicked up by your walking action too.

Quite a few DSLR's seem to have a "sensor cleaning cycle" ..any idea how that works??? Obviously DSLR's that do have a mirror protect the sensor a lot better but the 50 is totally exposed.

Do Sony have any recommended cleaning methods???

Chris

Re: Dirt on sensor
 

It is like the "old days" of DSLRs all over again!!!

Since about 2006 or so, many DSLR have "sensor shake" cleaning on start-up and shut-down, and also anti-static coatings on the material covering the sensor itself (the sensor is never actually "bare", there is always a glass cover over the micro-lenses and bayer pattern filter.

But now, we have all the large sensor video cameras, and so far, not too many have any "self cleaning".

The trick I always used on the old DSLRs to find dirt is to shoot a clear blue sky at a small aperture such as f18 or f22. Any dust on the "sensor" (actually it's protective cover) will show up as dark spots in the sky. Another good way to check for dust is by shooting any light source with an Expodisc white balance cap over the lens - produces the same results, but you don't have to wait for a cloudless day (plus it's a great white balance tool). Then you take the resulting image, and do a bit of levels compression (contrast boost) on it in your favorite photo editor, and at 100% magnification all the dust spots just jump right out at you.

OK, so now you know there is dirt on the sensor, what to do about it?

In the old days, we would clean the sensor with a special liquid called "Eclipse" (later "Eclipse 2") and ultra lint free swabs (PEC*PAD). You can see the details in this old article: Sensor Cleaning.

And this technique is certainly still valid, as are the products used. One US supplier is:
Cleaning Digital Cameras - Photographic Solutions, Inc.

Recently, I have been using the Sensor-Klear II from Lenspen. It seems to work well, but I'll caveat that by saying it works well when the sensor is not too dirty. My NEX6 arrived from the factory (kit lens installed & never removed), with enough dirt on the sensor that I had to wet clean it with Eclipse 2 + swabs first (and the NEX6 supposedly has sensor shake cleaning). This is far from the first time that I've received a camera in a sealed box straight from the factory with enough dirt already on the sensor to justify wet cleaning, it's actually pretty common. I guess the cameras are not assembled in a true clean room environment, and the manufacturers don't care enough to ship from the factory 100% clean. I use the Sensor-Klear on my FS700, but it is a bit of a different beast in that all you are cleaning is a layer of glass which protects the ND filter, and this glass is far removed from the sensor, so dust particles up there do not create the same sharp outline that they will on other cameras where the particle is lying right on the sensor.

Since a lot of people seem to be scared of the wet cleaning process (I've done it 100's of times since I went digital in 2000, and never once "broken" a sensor or camera), I'd probably suggest the Sensor-Klear as a first step, then wet cleaning only if there are still obvious, stubborn spots visible. Finally, if you do end up doing wet cleaning, keep in mind that you may have to try it 2, 3 or even more times, especially if you've never done it before, and you don't have the technique down pat.

Re: Dirt on sensor
 

ah yeah the Dust Bunnies!!! i can remember nervously cleaning my full frame Canon 1DS Mk2 for the first time many moons ago now with eclipse solution and a home made spatula and yes it takes lots of practice, that was before the in - camera integrated sensor cleaning systems and Dust Delete Data etc. not for the faint hearted,

I'm surprised Sony hasn't a system in place! what way does that work with other interchangeable lens models in their lineup?

Re: Dirt on sensor
 

Yes, I was nervous wet cleaning the old Canon D30 the first few times too, way back in spring 2001, after wondering why the sky was full of black blobs... but the key thing to remember is that in every exposed sensor camera ever made, you do not even come close to touching the bare silicon. Every sensor made to date has either plain glass, an IR cut filter, an anti-alias filter, or a combination of those covering the mico-lenses which in turn cover the bayer pattern filter. All this stuff is bonded together & sealed, so you are literally applying a super pure (*disclaimer - there may be some super exotic camera that I've not heard of that exposes bare silicon, and should not be wet cleaned, but if there is, it's not something you are likely to run across).

Here is one of the best tutorials on wet cleaning ever, continously online and updated regularly for over a decade: Copper Hill Images - CCD/CMOS Cleaning Tutorial - Introduction

The Sony website says this about the NEX6, which is the first NEX stills camera to incorporate any form of stay clean technology:
"Anti-Dust Technology helps keep the CMOS sensor clean, resulting in consistently clear pictures. First a static-free coating on the sensor's low-pass filter helps repel dust. Then vibration automatically dislodges dust from the sensor."

So far, I'm not impressed. I've only had to manually clean my Canon 7D sensor two times since the fall of 2009. I've now had to manually clean my NEX6 twice in two months.

Re: Dirt on sensor
 

Thx for the tips! Much appreciated. The Arctic Butterfly sensor brush finally removed all present dust or at least I don't notice any spots anymore in normal exposure when viewing a grey sky, see photo below of a before and after.
The dust got on the sensor at the casino I filmed when I changed lenses, the sensor is also out in the open with no protection or sensor cleaning tech at all, so I need to check before each important shoot.
That's why the metabones speed booster interests me because besides it's other advantages it also has a glass between the sensor and lens so no dirt can get in while changing lenses.

Re: Dirt on sensor
 

Hi Noa

This is also an excellent site and not dedicated to any product..The guy is a camera tech so he should know what he is talking about too.

Introduction - Cleaning Digital Cameras - D-SLR Sensor Cleaning.

Chris

Re: Dirt on sensor
 

Thx chris, the Copperhill Sensor Swabs tutorial that Juan posted is about as far as I am willing to go before I send it in to get cleaned, the copperhill cleaning method seemd fairly easy to do yourself and since teh sensor is easy to reach that shouldn(t be much of an issue. As long as Arctic Butterfly sensor brush does teh job I will use that though.

Re: Dirt on sensor
 

I keep a Giottas blower with the cameras at all times and use it on every lens change - and on the back of the lens with zooms set so that the rear element is withdrawn into the lens to have a fighting chance of getting stray dust out of the lens cavity.

Perhaps it a bit extreme but I have not yet had dust problems on any DSRL kit since the venerable Dynax 7D which I still use occasionally (like driving an old sports car!) through the a900, a77 and various NEXs - so just carrying on habits into the EA50. Perhaps I'ver been lucky!

Neil.

Re: Dirt on sensor
 

An item I wish came with the EA50 but doesn't is a blank cap for the diopter when it is not in use.. Mine is off and on all of the time. And one of the bags I use requires it to be removed. Since it is a diopter and not a lens it seems to be cheaply made and probably not sealed well. I have had other optics were a piece of dirt found its way onto the inside part of the glass. That will make you CRAZY.

Re: Dirt on sensor
 

The dust on the sensor seems to be a bigger issue as I have thought, as long as the stock lens stays on it's not a problem but if you like me do a shoot with several prime lenses that are changed quite often you should have something with you to assure there no dust during the shoot and especially check before you do a new shoot.

The last shoot I did in that church I again noticed a dust speck in my footage in the bright sky (you can even see it in my last film I did, which is visible in the very last shot) even though I cleaned the sensor before I started filming so today I used that arctic butterfly again which does a good job. It's kinda stupid that since there is a mechanical shutter present if you want to take pictures that also should be engaged when you shut down the camera so it would protect the sensor during lens changing, also seems like something they could fix through the firmware?

Re: Dirt on sensor
 

Hi Noa,

Apparently I have the same problem from frequent lens changes. Which arctic butterfly "kit" do you have?...I notice huge price differences among different options.

Thanks for your time.

Dan

Re: Dirt on sensor
 

It's a "arctic butterfly 724"

Re: Dirt on sensor
 

I have worked in some incredibly dirty environments that are brutal on gear. In NASCAR racing there is dust and dirt you can't see but you can feel it hitting you in the face. If you know your going into something that dirty it is not unusual to see us with RAIN COVERS on our gear on bright sunny days. Those are not just for victory lane celebrations.

I had one driver completely soak my camera with Gatorade as I took the shot. What a mess! I have had some drivers do some really mean things but this was not one of them. When your that close to the celebration it is just a consequence of the event. It was my fault for going in unprotected.

So wear your party hats when your going in dirty!

Steve