Sigma SD Quattro IR filter cleaning

[joe bosak]

I've found a lot of my recent pictures have dust blots, and determined that it's not on the back element of the lenses but on the filter. Now looking at the IR filter/cover, that's not very surprising - despite taking what I thought was a huge amount of care when changing lenses (only ever do it indoors, blow/wipe lens and body around the interface before moving anything, keep the body facing down, put lens caps on immediately), there's plenty of visible dust and fluff, and a squeezy-bulb-blower won't shift it at all.

So I'm wondering what's the best approach here? Wipe gently with a microfibre lens cloth with the filter in situ? I have no idea how delicate it is, except that when I received my old SD14 its filter was falling out and seemed gossamer-like, so I'm reluctant to remove it unless I have to.

Anyone have any advice here?

 

[Freakscene]

Sensor swabs and sensor cleaning solution. A microfibre cloth will just put more junk on the sensor.

I have no idea where you are, geographically: Camera Sensor Cleaning Kits | Camera Cleaning Kits | B&H

 

[joe bosak]

Thanks Freakscene. I'm in the UK. I hadn't thought sensor swabs might work... I can get some, no worries.

 

[Larry H-L]

Those sensor filters come out easily on the DP Quattro, there is a little tab that you can grab with tweezers. It might be easier to clean when removed. I’ve take mine out several times to shoot IR black and white.

 

[Deleted member 82967]

Sensor swabs and sensor cleaning solution.

He's talking about the so-called dust cover in the lens mount.

A microfibre cloth will just put more junk on the sensor.

Yes, old ones do start shedding micro-fibers in use but, having said that, on all the previous Sigma DSLR models, I used micro-fiber cloths with a bit of 91% IPA on them followed by a light dry rub - to good effect.

My experience is that stuff on the dust covers doesn't show up sharp in the image and is often unnoticeable, so the OP should take a careful look at the sensor when the cover is out.

 

[joe bosak]

I've got some soft microfibre cloths that are hardly used, maybe that's where to start then. The dust cover has never been removed - or not in the fews years I've had the camera.

I took a few shots pointing at something white, out of focus. The dust only showed up at small apertures, though in a different place from the blots in the photos I noticed it in.

 

[trix4ever]

I believe xpatUSA is correct, no amount of crap on the removable filter shows up in images, it's way too far out of focus.
Don't be afraid of removing it, I do it all the time.
Simply remove it and try doing a sensor clean wirh a rocket blower or Arctic butterfly type brush. I'm afraid if that doesn't work you'll be up for a wet clean.
My Sd Quattro sensor always seems to need cleaning, quite disappointing as I thought the front dust filter was a great idea.

 

[joe bosak]

Interesting, thanks, I'd not heard of the arctic butterfly before.

 

[trix4ever]

I actually use a clone off ebay, works great for 20% of the cost.

 

[joe bosak]

So, managed to do the necessary. Can't say I found the instructions for removing the dust cover/filter easy to follow, mine has a springy catch on one side and not the other and needs to be wriggled in at a kind of 45 deree angle, needless to say I dropped it on the carpet at one point too. Clumsiness a speciality.

But it's back in place and no spots on my test image. I just used a blower on the sensor as there was no visible dust on it (nor that showed on a test shot without the filter), but some bigs bits on the dust cover.

Anyhow, go there, thanks all for your help. Much prefer the cleaning on my old Mamiya, just slip the ZD back off and blow the sensor - very quick and easy!

 

[shawn]

My Sd Quattro sensor always seems to need cleaning, quite disappointing as I thought the front dust filter was a great idea.

I wonder if the filters position was really more about trying to reduce color smearing on the sensor by thinning the filter stack at the sensor itself. Then Sigma made it removable to be able to clean the sensor too.

 

[shawn]

Anyhow, go there, thanks all for your help. Much prefer the cleaning on my old Mamiya, just slip the ZD back off and blow the sensor - very quick and easy!

The removable hot mirror opens up other possibilities though. When I had the sd Quattro H I made an IR filter that popped in there.