Sensor cleaning

[jimbobuk]

Before receiving my R-D1 I found a review that was critical about dust stops on the R-D1 and started a thread on it here

http://www.rangefinderforum.com/forums/showthread.php?t=17802

He was critical of there being no way to clean the sensor, and as that thread explains and as i'd even realised just by reading reviews, you can of course clean the sensor by using the bulb exposure mode to keep the shutter open.. also taking out the SD card according to epson powers down the sensor for even more protection against damage.

Well I went out and took some shots yesterday and was mostly pleased with them.. frustratingly there were 3-4 really noticable and dark dust blobs in most images with a bright background.. frustrating as i'd not noticed them on all the other images i'd took until that point.

This morning i had a good luck at the lens and cleaned it and took some more test shots of just the sky.. it confirmed that even with the lens cleaned it still had pronounced spots.. I've attached an image of how it was before, called before.jpg.

I took the plunge and decided to have a glance at the sensor.. looking through with the lens off and catching the sunlight on it i could see quite a pronounced set of dust spots on the sensor itself mirroring what i roughly could see in the images. Using my lens blower i went ahead and blew the spots away, luckily they moved quite easily and within no amount of time the sensor looked pretty much clear.. reattaching the lens and taking some more test shots revealed that the problem had been pretty much fixed. I've attached another picture called after.jpg. The pronounced blobs have all gone (ok these images are downscaled to make them small, but you could make out the blobs in the before shot at the same scale).

Stuck with the epson raw plugin I started looking a bit closer and noticed that zoomed in you could still see smaller subtler blobs much fainter.. only really visible either at 1:1 viewing of the file, or even at 1:2 in some occasions, i've attached an after_cropped.jpg file that shows a couple of spots at 1:1.

I took the camera apart again and looked closer.. using a torch i managed to get the right angle to see these even smaller flecks of dust that are on the sensor.. I had a real good go at trying to blow them away but as you sometimes get on your lens, or filters, blowing just isn't moving them..

I'd never really stuck the blower too far in, didn't want to touch the sensor at all.. at one point the shutter did close.. the battery is fully charged and i didn't think i'd moved the finger off the shutter (i have no remote release with a locked open setting to keep the shutter open.. its not THAT hard to hold the camera and the shutter down whilst looking inside) .. This worries me a bit if i had had anything deeper in.

Anyways looking at the sensor and remembering what the sensor in my Canon 350D looked like (ok thats a CMOS chip but still) it definitely looks like there is a filter in front of the sensor itself which is where i'm seeing the dust (i hope anyways if its underneath this then you'll never be able to clean it, without taking it apart in a horrible way.. i'm assuming the sensor block is air tight sealed anyways) Is this the case.. I know the general concensus is NEVER touch the sensor.. its something that I've always been happy to observe so far with my canon.. I also know that you can buy specific sensor cleaning brushes, so some people clearly think its ok to do it. One such example is described here

http://www.visibledust.com/

My question after all this is who has tried physically cleaning their sensor with such a cleaning brush?

Is there an inert protective filter on top of the sensor which is where the dust is collecting that unlike perhaps a naked CCD sensor wouldn't wreck itself under physical pressure?

Its the same sensor as in the Nikon D100/D70 isn't it... anyone know if owners of that have figured out that due to this front filter its safer to clean the sensor than with some other cameras that just have an exposed, naked sensor..

All in all its very subtle now, though still sometimes visible.. bright backgrounds only seem to show it up, tho i do take a lot of shots of sky.. I'll be happy to not touch it, never clean it again, only blow the bigger blobs off if they occur again, but it'd be nice to know if a handful of people have managed to safely get stubborn spots off the sensor with one of these brushes. It'd also be a good warning to know if anyone had ever tried this and caused damage to their R-D1, or Nikon Dxxx..

Cheers guys

 

[Gid]

Hi Jim,

I've had one instance of sensor dust - actually filter dust as its the filter you can see. I used Eclipse cleaning fluid and sensor swab pads. Used 3 or 4 of them to remove the dust (3 or 4 attempts to get the hang of it). I haven't had a problem since and I wouldn't hesitate to do it again when the need arises. I do have a locking cable release, but misplaced it at the time of cleaning and so just held my finger on the shutter release in bulb mode. However, next time I won't attempt it without the locking cable release - just way too risky. You can get the fluid and swabs from most places (Nikon D100/D70) size.

Hope this helps.

Gid

 

[jimbobuk]

Cheers gid..

I had more of a look around that site i linked.. looks comprehensive.. have seen it before.. not quite sure how they've managed to turn it into a package of quite substantial value.

I think the things i can see are quite small and just dust.. i'd hope light physical contact along with that brushes "lifting" static action would be sufficient to lift it.. i'll probably leave it for now and see if i notice it in many more pictures.

Using liquids on the thing is the next step and does worry me a bit 🙂

Be nice to know there was a small air gap between that filter and the sensor itself.. perhaps it was held off of the sensor by feet at the border.. ie. you could apply reasonable pressure not enough to flex the filter by even 1mm and be sure it would NEVER be putting pressure on to the sensitive sensor itself.

Has anyone ever been quite thorough in taking these things apart and figuring out how tolerant they are...

Cheers

 

[kaiyen]

I realize that the idea of cleaning the sensor through any form of direct contact is perhaps a bit disturbing. But it is a perfectly normal thing for a digital camera with interchangeable lenses and, to be blunt, you need to get over it. You _will_ need to clean it at some point, with a brush. And perhaps with liquid if something is really stuck.

I first recommend that you go to http://bythom.com/cleaning.htm and read that. There are links to the two main products you'll want to use. I have both, but have never needed to use the swabs - if I use the brush properly and often enough, I never get dust stuck that won't come off.

If you go to any repair shop they will likely use these exact same items on your camera anyway.

And fyi - the filter on top does not come off, and I think it's actually standard on all sensors. There aren't any truly exposed sensors in any camera.

allan

 

[rvaubel]

Dust on sensor

Dust on sensor

Jim
If you want to emphasize the foot print of the dust on the sensor, shoot against a plain background (the sky works) at a the smallest F number your lens has. It doesnt matter which lens or even if it is in focus. Set the exposure so you get a light image but not too overexposed. The small F number will cause the light path to cast distinct dust shadows, no more blobs. Basically, you will see every piece of debris that even thought of making its home on your sensor. But a word of caution.... dont try to get everything!! This test is more sensitive than your ability to see dust blobs in actual practice. How often do you shoot a plain sky at F22? Remember at more normal F# that dust mote will become blurrier and blurrier.
Try leaving some of the smaller dust particles and see what actually shows up in practice. If you like shooting landscapes with huge DOFs then you will be more picky than an available light cameraslinger @ F1.4
Dont risk scratching the IR coating on the glass filter covering the sensor, as replacement cost $200 if done by a company that supports its product. And Epson...... well we dont want to get into that.
Rex
AKA "Wrecks"

 

[jan normandale]

Don't forget to check our 'sister site' DSLR for more digital people.

http://www.dslrexchange.com/

 

[rvaubel]

Dust on sensor

Dust on sensor

Jim
If you want to emphasize the foot print of the dust on the sensor, shoot against a plain background (the sky works) at a the smallest F number your lens has. It doesnt matter which lens or even if it is in focus. Set the exposure so you get a light image but not too overexposed. The small F number will cause the light path to cast distinct dust shadows, no more blobs. Basically, you will see every piece of debris that even thought of making its home on your sensor. But a word of caution.... dont try to get everything!! This test is more sensitive than your ability to see dust blobs in actual practice. How often do you shoot a plain sky at F22? Remember at more normal F# that dust mote will become blurrier and blurrier.
Try leaving some of the smaller dust particles and see what actually shows up in practice. If you like shooting landscapes with huge DOFs then you will be more picky than an available light cameraslinger @ F1.4
Dont risk scratching the IR coating on the glass filter covering the sensor, as replacement cost $200 if done by a company that supports its product. And Epson...... well we dont want to get into that.
Rex
AKA "Wrecks"

 

[RichC]

For a sensible - and cheap - alternative to the ridiculously priced Sensor Brush, read this: http://snipurl.com/mqvk.

I'm a chemist with long experience of the behaviour and properties of plastics, and agree 100% with what Petteri says in tha above link (his other articles are also worth reading!)