How to check 20D Sensor for Dust

[DavoMrMac]

OK, first off, I changed my 350D for a 20D today, I was struggling with the size of the body and feel.

My 20D was meant to be new, just delivered, but I noticed the battery was open and time/date set, so I guessed someone tried it. Now I am worrying about dust.

I took a couple of shots of white paper, one showed spots, the other didn't, so I guess this was in the paper.

Even though I set a custom white balance my paper came out grey, hmmmmm, so advice needed here.

Anyway, one of meany threads I have put up today, the main question of this one is, could someone give me a step-by-step on how to check my sensor is clean.

Thank you.

[cmM]

take a shot of the sky, focus to infinity (manual), stop the lens down to like f/22 or so, increase the contrast in PS, and you'll see the spots. That's how I usually do it

Good luck, I hope it's clean. ;)

[DavoMrMac]

thanks for that, could I try the same taking a pic of my LCD screen as it is now dark here in the UK?

[DavoMrMac]

cmM - I took a shot of my screen and blew the contrast out - sooooo sooooo dirty, loadsa specks.

This is a brand new camera as of today, about three hours ago, so I do not think the sensor should be this dirty.

Do you think I should ask them for another and/or ask them to clean it?

[dhbailey]

If you paid for a brand new camera and the time/date was already set on it and the battery was already unwrapped, you should bring the camera back and demand a new-in-box-never-opened camera.

Of course, even on a new camera you can have dust on the sensor.

Blue sky shots are the best way to check for spots. When you notice you have spots, you clean the sensor (I've used Copperhill on my 20D and it's not difficult), then take another picture of the sky and see if it has spots on it.

First recourse against spots, though, is simply to use a powerful hand-blower like the Giotto's Rocket Blower (never use canned air or an air compressor!).

[robertwgross]

If you paid for a brand new camera and the time/date was already set on it and the battery was already unwrapped, you should bring the camera back and demand a new-in-box-never-opened camera.

I don't know about discount stores, but in some Canon dealerships, they will open up a box and do a quick check-out of the camera. Sometimes they do this to update firmware version prior to a sale.

---Bob Gross---

[DavoMrMac]

Thanks for all the advice, I will take the blower to it, but will ask them to change it anyway. I have a sneaking suspiscion it was a display model or return.

[wintoid]

Mine was brand new from Jessops in the UK, and the sensor was filthy. A blower didn't shift it, and I've spent some time doing the "Copperhill" method of cleaning it, which has made substantial progress. However, as it's not actually preventing me from taking good pictures, I've stopped worrying and just kept shooting. Maybe I'll clean it again some time soon.

[DavoMrMac]

Ditto, Jessops UK too.

Was your box unsealed? Battery unsealed? Date and Time Set?

Mine is filthy, going back, going to insist on a sealed one.

[wintoid]

Honestly, I don't recall. Usually, I would have wanted to take it back and get a dust-free one, but the damn thing just welded itself to my hand as soon as I got it out of the box :D 5000 shots later and I'm still thinking "ooh I must clean the sensor again". I've had 3 lockups too, with the latest firmware, but I've decided not to worry.

[Moostyman]

In the perfect world a clean sensor would be ideal but in reality when I get dust appearing in images I have already taken, in most cases, I can clone them out in PS.

Cleaning the sensor is the first step but using the clone tool gets rid of those little "dusties' that appear in our pics.:)

[mr.photoguy]

I just cleaned mine yesterday.
I couldn't believe how filthy the sensor was.
Then again, I did have my camera since thanksgiving.

[gasrocks]

Slight varation on technigue. I do not want to do clean up afterwards. I do a lot of shooting on any given day and want to check that sensor for dust "on the go." Av mode to f/22(biggest # you have), set exp. comp to 1/3 or 2/3 dark, focus to closest (not inf.), take a shot or two of the blue sky (blank wall if not avail.) Go to review. Hit the + key (by your right thumb - I have a 20D) about 6 times. Now - using the joystick - pan around the image. Any dust will be very obvious. Delete the test image and finish shooting.