Dirty DSLR sensor?

[Beardy Bob]

Does anyone have issues with dirt building up on the sensor through constant removal/attachment of the camera body to the scope? I have a 350d so it doesn't have a self-cleaning mechanism like the newer models. I only bought it recently, but the camera shop said that it is potentially a big problem (although much less visible when using wider apertures, which makes sense).

[jgs001]

I have done Bob. The 450d has self cleaning, but I have taken to physically cleaning the sensor a couple of times. The quickest way to test, zoom a lens to full zoom (this normally allows you to close the aperture further), set to manual focus, you don't want this shot in focus, pop the flash, set the camera to manual, shutter of 1/160 ish, aperture the biggest number you can get and take a photo of a blank white wall, fridge or something like that. This will show up any dust on the sensor. There's a couple of things you can do. Minimise the time that the camera is uncapped. For imaging, I have a MaxDSLR fitting, and I keep a Skywatcher 2" LP filter attached. I quickly swap the lens for that fitting before connecting to the scope. The other option is something like the CLS EOS Clip filter, it's an LP filter, but sits inside the body of the camera and will prevent dust from entering.

[Dave Smith]

I originally had a 350D and later a 20D. Yes dust bunnies did show up from time to time but it wasn't a major issue. Cleaning the sensor is quite straightforward.

I now use a 40D which self cleans and I haven't had to clean it yet in over a year.

Dave

[jgs001]

Oh one other thing Bob, if you take flats, that deals with the dust in processing. It's very easy to do with the C80ED as the tube aperture is small enough. I use a laptop with notepad maximised. It's probably not the best way by a long chalk, but it does the job for me, removing any vignetting, dust and dirt etc.

[Beardy Bob]

Thanks guys. It's good to be prepared with such knowledge. What do you use to clean it?

[FLO]

We have just become a stockist of Digipad sensor cleaning swabs and fluid, we'll add them to FLO's site and announce them in the sponsor's section later.

HTH

[jgs001]

Start with a rocket blower. Make sure your battery is fully charged. Mount the camera on a tripod, lens mount pointed downwards. blow the rocket blower a couple of times to ensure there's no dust in it (you don't want to add more ). In the menu there should be an option for cleaning the sensor. Use the rocket blower and blow hard across the sensor, try to avoid pushing the nozzle to far into the body of the camera. Turning off the camera will probably reset it, that's how the 450d works.

Repeat the test exposure with the lens in place. If there's still dirt, repeat the cleaning process. Do this 2 or 3 times. Bear in mind a rocket blower may well just shift the dust around inside the body, most of the time this combined with the self cleaning does the job nicely.

If this hasn't done the trick, you'll need to use one of the other, contact based cleaning methods.

I've used a wet cleaning system, using pre packed, clean pads designed for the job, with the proper sensor cleaning fluid and that worked brilliantly. There are several fluids and you need to use the correct one for your sensor. I know of someone that was using the wrong fluid and no matter how many times he cleaned, it didn't shift the dust. He changed to the correct fluid and the next clean removed the lot. This process is also a lot easier done with the camera tripod mounted pointing down a bit. It leaves both hands free.

A word of caution, if the power goes, the shutter and mirror cell will flip back into place and you really don't want something inside the body when that happens, thus making sure you're fully charged.

It sounds scary the first time, but it's surprisingly easy to do.

[Beardy Bob]

Aha, cleaning pads would be useful.

Just noticed your coments on 'flats', jgs001.I will probably have to look for a tutorial (or post a separate thread) on flats and darks etc. I understand the concepts of 'darks', but have no idea about the theory of 'flats'. I've seen the option to use them in Deep Sky Stacker, but have ignored it up to now. The C80ED will be my first proper imaging scope (when it arrives - i only ordered it last night so i'm probably getting ahead of myself slightly through the excitement of it all!).

[jgs001]

The DSS help option is quite good on the various adjustment frames, and gives some advice on how to take them.

[Beardy Bob]

I will have a proper look at the DSS help some time. Thanks.

As for keeping the sensor clean, once the tripod is polar aligned and the position marked out, could you potentially store the camera mounted on the telescope in the shed? (I'm prepared for a barrage of responses explaining exactly why not to do this!)

[Psychobilly]

My DSLR's live on the scopes...

Billy...

[MaCross]

I find the arctic butterfly from visibledust quite handy and fairly easy to use. It is a brush that spins very fast and you just brush it over the sensor, eh voila... clean...

http://www.visibledust.com/products3.php?pid=2

[Beardy Bob]

That's interesting to hear psychobilly. That would certainly minimise the amount of dust etc getting into the camera. When it is all left hooked up together, does your scope and camera stay in the shed or you do you keep it all indoors?

[Psychobilly]

The longest its been in the "shed" is 14 days over christmas when it got down to -7C... until the "shed" is finished I bring the gear in when theres no one around the house... hopefully the "shed" will be finished this spring another few hundred to spend on it to make it as secure as I want it to be before the gear moves in... I am going to use 2 part foam to "bond" the inner and outer walls together ...

Here's the "shed"...

Billy...

[Beardy Bob]

Yeah, see what you mean by "shed" billy. It's a bit small for a shed - more a small shack.

[Psychobilly]

[Beardy Bob]

Sorry psychobilly, couldn't resist.

Looks like quite a project. Is it all your own work?

[Kokatha man]

I had major dust problems with my modded 20d.....I now do something that may sound a bit bizarre but is really easy once you've done it a few times, and with the dusty roads I travel down here in Oz I have complete protection for gear when travelling too.

I use a couple of those zippered "pillow preservers" (the ladies will know even if the menfolk don't!!!) that cost about $5 for a pack of 3.....put the lens or whatever and camera in the bag, zip up and changeover from the outside which is simple (they're semi-transparent and their dust exclusion properties are better than most vacuum cleaner's filters.....I have a test example image to show if anyone's interested.)

[Psychobilly]

Sorry psychobilly, couldn't resist.

Looks like quite a project. Is it all your own work?

Yep Designed and Built it myself...