Dust in viewfinder

Excuse my ignorance, electric turd, but what is a "rocket blower" that everybody is talking about? Is is the same thing as the compressed-gas duster called "Dust-Off" that I use for cleaning the keyboard, lenses and other stuff?

Its a rubber bulb blower, here's a link to it on B&H. Oh and by the way don't ever be afraid to be "ignorant" although your not, asking questions is how we ALL learned so if have a question were here to help.

http://www.bhphotovide​o.com …lower&image.x=0​&image.y=0

electric turd wrote:
Its a rubber bulb blower, here's a link to it on B&H. Oh and by the way don't ever be afraid to be "ignorant" although your not, asking questions is how we ALL learned so if have a question were here to help.

http://www.bhphotovide​o.com …lower&image.x=0​&image.y=0

Ahhh! Thanks!

I've got exactly the same problem on my 350D as well. I've used the blower to clean the sensor. How do I use it to clean the focussing screen?

The focussing screen's the whitish plastic panel at the top of the mirror box. Give that a couple of shots with the blower.

roger the photographer wrote:
Excuse my ignorance, electric turd, but what is a "rocket blower" that everybody is talking about? Is is the same thing as the compressed-gas duster called "Dust-Off" that I use for cleaning the keyboard, lenses and other stuff?

Roger - never use "Dust-Off" or any similar "canned air" product around your camera. The liquid in those cans is very hazardous to the health of parts in your camera. If you got a mist or droplets of the liquid in the spray, it could damage plastic parts, the mirror, etc.

Too many folks really think the cans have compressed air in them, and that is the furthest thing from the truth. The cans contain a liquid solvent that vaporizes when the pressure is reduced, and there is no guarantee that what comes out is all gaseous.

I've had this problem with my 20D. I tried to blow it out with the innodesk blower, had no luck. Then I tried to statically pick it up with the sensor sweep but had no luck, it just moved the dust specs around. The angle of the screen requires something at a 90 degree angle to reach. I got a Q-tip, bent the head to around 90 degrees, then wrapped it in a little bit of saran wrap. I then procceded to rub it on the vellum paper to charge it, i then dabbed it on the screen to pick up the dust. Worked beautifully!

Wouldn't a vacuum be better than a blower? Do they make one for camera's ?

Don't fret, Skip, I wouldn't dare do it, that's why I asked. I find these cans quite useful for my keyboard indeed, and even there with some care.

What happens with such a can in fact, chemically speaking, is that the gaseous fraction of the liquid propellant (which is in a gas-liquid equilibrium under pressure) gets out as long as you hold the can perfectly vertical, you do not agitate it, it's not too full, et cetera. When the gas gets out, this equilibrium is broken and more liquid is forced into the gaseous state, thus reducing drastically the inside temperature, reducing output and greatly augmenting the risk of "liquid spit" for lack of a better expression.

In the case of Dust-Off, there is no "air" as far as I know, only 1,1-difluoroethane, which is the gas and the propellant.

So no, as you say, this is not the best friend for the delicate camera parts that can be permanently damaged by this very cold liquid spit.

I'm also a chemist...

Roger - where were you when there were arguments going on that the "canned air" was perfectly safe to use on cameras? I couldn't convince the few folks who had their minds made up that they were wrong. Thanks for your comments.

In fact, I'm nervous even when I use our lab's highly filtered centrally compressed air system, which I did a few times and won't do again. Even in a lab, one should do this only with perfect control over pressure, which is not always the case.

At home, I've not found a satisfying way to get rid of dust in fact. If you know of a way to really get rid of dust, not just move it around inside the body... , pray tell me! I can do an "almost decent" job. A good one? No.

Canned air inside a 5D body... Woohoo!

roger the photographer wrote:
At home, I've not found a satisfying way to get rid of dust in fact. If you know of a way to really get rid of dust, not just move it around inside the body... , pray tell me!

Why, of course you should try rolled-up duct tape .

Seriously, I use a squeeze-bulb blower and keep the open mirror box pointed down so that gravity helps. Then, if need be, I clean the sensor using the Copperhill system (see this link: http://www.pbase.com/c​opperhill/ccd_cleaning)

SkipD wrote:
Why, of course you should try rolled-up duct tape .

Seriously, I use a squeeze-bulb blower and keep the open mirror box pointed down so that gravity helps. Then, if need be, I clean the sensor using the Copperhill system (see this link: http://www.pbase.com/c​opperhill/ccd_cleaning)

Well, Skip, this seems about what I usually do. There is no way around this, you've got to use something like a swat and ethanol from time to time. As I do switch lenses very frequently, I probably get more dust than many...

I'll go on doing it like that. Steady hands, here we go!

BTW, I had never tried duct tape before. Didn't try to stuff the innards with lint-free tissue either. Must be retarded.

Thanks for the opinions on this.

Even though I am a fairly knowledgeable electronics tech, I don't know enough about the physical properties of the sensors in our cameras. However, folks have suggested that keeping the camera powered during lens changes might leave some static charge on the sensor while the mirror box is open. If that were true, and if there were an open path past the shutter, dust might be attracted to the sensor when changing lenses with the camera powered. Take that for what it's worth.

I do try to power down for lens changes, but not really for this reason. I do it primarily so that shorting connections at the lens terminals won't possibly cause any problems.

I've considered the "power down during lens changes so the sensor doesn't attract dust" to be bogus. Recently I had a chance to talk with a Canon rep and asked him about this (trying to keep the question phrasing neutral). He said, essentially, that a lens change forces a power-down, though they won't broadcast this.