Sensor cleaning...?

ChrisBlaze wrote in post #2350636
my question is how do you clean the sensor when it has the shielding over it for the self cleaning?

In "normal" DSLR's w/o the sensor cleaning unit, the dust sticks to the sensor, right?
Well, in the EOS 400D there indeed is a thin sheet of plastic in front of the sensor, so the dust doesn't adhere directly to the sensor, but to the plastic, where it is supposed to be "vibrated off" with the piezoelectric blah blah thingy. Many reviewers, however, don't exactly praise the function of the sensor cleaning unit, so I'll probably have to remove the stubborn dust by hand.

Glenn NK wrote in post #2350601
IMy last shot of a shoot is of the clear sky (white clouds or plain light coloured walls will do) with the lens stopped right down. Then when I download my pics, I have one showing the condition of my sensor - if needed, it gets cleaned for the next shooting.

I have a couple of questions about those sky shots. First, I'm still trying to figure out why stopping down matters (I haven't had a time to sketch an optical diagram yet, or maybe I could figure it out myself). Second, does focus matter? I seem to see blobs better when I'm close-focused. Third, does lens length matter? If so, is it more important to use a long lens or to go for a closer focus?

Currently looking for the time to do a practice run on a filter before my first cleaning...

ChrisBlaze wrote in post #2350636
my question is how do you clean the sensor when it has the shielding over it for the self cleaning?

BrewsterPilot wrote in post #2351642
In "normal" DSLR's w/o the sensor cleaning unit, the dust sticks to the sensor, right?
Well, in the EOS 400D there indeed is a thin sheet of plastic in front of the sensor, so the dust doesn't adhere directly to the sensor, but to the plastic, where it is supposed to be "vibrated off" with the piezoelectric blah blah thingy. Many reviewers, however, don't exactly praise the function of the sensor cleaning unit, so I'll probably have to remove the stubborn dust by hand.

gkuenning wrote in post #2355798
I have a couple of questions about those sky shots. First, I'm still trying to figure out why stopping down matters (I haven't had a time to sketch an optical diagram yet, or maybe I could figure it out myself). Second, does focus matter? I seem to see blobs better when I'm close-focused. Third, does lens length matter? If so, is it more important to use a long lens or to go for a closer focus?

Currently looking for the time to do a practice run on a filter before my first cleaning...

You are never cleaning the sensor...you only clean the filter over the sensor. All DSLR's have a filter over the sensor to protect it. The dust sticks to the filter and is what we need to remove.

Stopping down the lens increases the depth of field in an image...as you stop it down further and further...more comes into focus. By f/16 or so...dust on the sensor starts to become very evident. It doesn't matter what you focus on....you can focus on a white wall at 2' or the sky at infinity...both shots will expose dust bunnies on the sensor as long as the lens is stopped down.

I believe that the conductive coating on the xti sensor window is made of Indium Tin oxide. In my experience, this coating can be rather soft, so I would treat it with some caution!

gkuenning wrote in post #2355798
I have a couple of questions about those sky shots. First, I'm still trying to figure out why stopping down matters (I haven't had a time to sketch an optical diagram yet, or maybe I could figure it out myself). Second, does focus matter? I seem to see blobs better when I'm close-focused. Third, does lens length matter? If so, is it more important to use a long lens or to go for a closer focus?

Currently looking for the time to do a practice run on a filter before my first cleaning...

Stopping down matters because then you're illuminating the dust with a point light source rather than an area light source. Look at your shadow outside on a bright, sunny day and notice the crisp edges. Then go inside unnder fluorescent lights and see how diffuse it gets. Or light from a flash both direct and indirect.

If you're not focussed on your subject it'll further blur the background "noise", masking details in the picture that might be mistaken for dust. Think OOF blur.

Lens f.l. doesn't matter except that longer lenses have shallower DoF and typically stop down further, both of which will help accentuate the dust.

Today the sky is finally clear and blue, so I'm going out for a few hours.

I will check the sensor again, but from previous indoor testing (shooting at a light coloured wall), I found that short focal length shows the dirt spots clearer that longer focal length (24 - 105L). So I test at 24 mm.

Southswede wrote in post #2348323
I can't remember which one, but I tried the Lens Pen recomendation of one of the moderators. It is faster and does a better job than any other method I have tried.

how do you use the lens pen to clean the sensor? I'm can't understand how to do that

OS220sl wrote in post #2349208
I just finished my first successful sensor cleaning on my 30D. I pickup a Returned 30D with Kit lens form Costco about month ago. The price was right. After extensive testing the only thing I found wrong with the camera was the sensor was very dusty.

I tried cleaning it with air from a mustard shaped bottle. The bottle was new and I also washed it very good. I use them in my business for holding different chemicals. It took some dust off, but not enough. So I purchased a sensor cleaning kit with the rocket blower from CleaningDigitalCameras​.com. Comes with the Rocket Blower and everything you need to wet clean the sensor.

I first blew off the sensor with the RB about 10 times. Then I used the sensor swab wrapped with a Pec-Pad and two drops of Eclipse. Took one swipe across the top half of the sensor flipped the sensor swap over and used the other edge and swiped the bottom half of the sensor. Put everything back together and took some test shots, Expecting to find a few spec's of dust left over. But to my surprise it was spotless. Clean as a Whistle. The whole kit cost me $37 shipped. They have extensive information on their web page on sensor cleaning. Another source for sensor cleaning supplies is www.copperhillimages.c​om I have not used them but have heard good things.

Jon III

I clean my XT the same way, with a sensor swab wrapped with a Pec-Pad and two drops of Eclipse. It's so very easy, I can't believe I was so paranoid for so long about "not touching the sensor."