PDA

View Full Version : dirty sensor ?



thegrump
31-03-2017, 9:15am
Was not sure were to put this one. Anyway, I did a dust check yesterday and to my surprise YUCK. I have the cleaning gear, I cleaned the lenses, mirror, etc. I did a generous blow out on the sensor, many times, but as you can see, dust? is still there. Not as bad as the start. What next, to the professionals. I can not see any dust even used a magnifier.

130230

Gazza
31-03-2017, 10:21am
Still a lot there when ya darken things up a bit.....

130231

Warbler
31-03-2017, 10:41am
The bane of a photographer's life.... I've found that no one method works every time. I've used everything from canned air to wet pads to static-charged brushes, to sticky pads. Sometimes I think I'm just moving the dust around, rather than removing it. The wet swabs still leave fibres even though they say they won't. What I try to do is use the dry methods first, but if the dust is fused on to the sensor, I'll go to the wet swabs or the sticky pads. I always finish with the rocket blower and the brush. It gets expensive using five swabs for a single sensor. :D Living away from a capitol city means I have to do it all myself. You might it less hassle and cheaper in the long run to take it to Camera Clinic in Easey Steet, Collingwood.

MissionMan
31-03-2017, 11:11am
I've heard good things about the sensor gel sticks but you have to be careful and only use the originals, not the cheap replicas. Apparently Leica are using these now as well.

Mary Anne
31-03-2017, 11:25am
You did not mention you cleaned the Sensor, only a generous blow out what ever that is ?

I have been cleaning my sensors for many years shooting Macro at small apertures will show all the dust.
Mostly caused by swapping lenses all the time when you only have one camera, even facing it away from the wind and doing it downwards
I don't use the rocket blower as I found it seems to distributed the dust more over the sensor.
Sheet of white paper on table camera facing down a few puffs from a can of Air its amazing what falls out.
Given up on the wet swabs, and all those things.. Now all I use is the eyelead sensor gel stick it works for me on my Canon cameras.

arthurking83
31-03-2017, 12:28pm
Was not sure were to put this one. Anyway, I did a dust check yesterday and to my surprise YUCK. I have the cleaning gear, I cleaned the lenses, mirror, etc. ....

No point in doing that. The sensor can't see dust on the lens or mirror or anything else so close to it.(ie. it literally can't focus close enough to see such stuff)


I did a generous blow out on the sensor, many times, but as you can see, dust? is still there ....

(if I can assume you used a blower bulb??)My guess is that blowing out the sensor like that, is that you have blown more dust onto the sensor. Been there, done that .. maybe even still have the proof to show it.
Yeah, I did tests to see what method you should/shouldn't use or try to clean a sensor.

* Blower bulbs are about 10x worse than just leaving it alone.
* Can of air(careful of which brand you choose) can be helpful, and can do what may have been required from a blast of air anyhow.
* a specific sensor brush. Not just any brush, sensor brushes have to be statically charged and can remove any not baked in dust spots.
* wet clean(ie. like a copperhill cleaning kit). You use a particular fluid on a particular lint free cloth and swab it across the sensor. They usually require a few attempts to clean up fully.
* I use the gel stamp method now. Quickest easiest and cleanest/most thorough. It's a gel like pad on a stick. You press the flat end on a bit of (specific) sticky thing, it removes the dust off the sticky gel pad. You then (lightly) press the gel pad on the sensor. The dust on the sensor sticks to the gel pad .. and repeat. Gel pad is about 1/4 the size of a sensor area, so it needs to be done repeatedly just for the coverage, and also for any baked in dust.


I can not see any dust even used a magnifier.....
if you could then you should be able to see minute detail on the surface of the moon on any given night with your naked eye! The dust isn't dust as you know it(ie. around the house/car/etc). It's microscopic dust. You need a powerful microscope to see it.


if all that has deflated your enthusiasm now, hopefully this will re-inflate it a little.

Aperture!

Be mindful of your aperture value to minimise the dust bunny issue like you have.
Obviously your aperture value will be more dependent on what you are shooting more than worrying about dust, but if you can get away with f/5.6 instead of f/11 or smaller(ie. larger number), then choose the larger(smaller number) for apertue.

Why?(I'm glad you asked!!) .. assuming that you did, so I'll go on ...

What you see on the sensor there isn't the dust, it's the shadow of the dust .. that is, not allowing light through as much as the areas on the sensor where there is no dust.
So the dark spots are just micro shadows. The dust isn't on the sensor, it's on the filter that sits on the sensor(AA filter and IR filter .. they're set up in a stack).
Removing the filters is hard, but doing so will give you a clean line of sight onto the sensor. But you don't want to do that, as when dust gets onto the sensor it can't be cleaned!!!!
So the dust spots are a few parts of a millimeters above the sensor material on the surface of the filter material, so what you see is the shadow of the dust spot captured by the sensor.
As you know, if you stop the lens down with aperture, it concentrates all the light rays into a more focused beam. Focusing the lens makes no difference, stopped down lens concentrates the light beams after the aperture.
So your aperture acts like a focusing mechanism at this point in the optical system.
Smaller aperture(higher f number) = more concentrated. Large aperturee = less concentrated.

I think you have a fast f/1.8 lens ... try it.
Similar photo subject for the test. Focus to infinity. Set image exposure about +1Ev brighter to help with contrast too.

Now, set aperture on lens to f/1.8. You will see no dust.
Set aperture to f/16(I'm pretty sure that's about maximum for a 50/1.8) now you will see the dust. This means it's on the sensor.

Finally(I hear you say/think! :D)
Do something about it!
Why?(glad you keep asking such pertinent questions).
if you don't, and you keep shooting, you bake the dust spots even more.
Baking dust spots is a euphemism to explain that they become statically baked in. They get baked on because the sensor created a static charge. The dust is already in the camera. Nothing you can do about it. The dust is so small(remember it's microscopic!) you cant stop it. You can minimise it, you can clean it, but you can't stop it. You can also minimise the effect it produces on the image(ie. aperture value), but again it's always going to be there and get there .. fact of life with digital sensors.
Leaving it, and continually firing off exposures will allow the sensor to produce more static charge and attract more dust and bake in the spots already there.

See above for the steps you can do to clean it.

I've done a tute on here (http://www.ausphotography.net.au/forum/showthread.php?53283-Sensor-cleaning-the-Copperhill-way&highlight=copperhill) about using the copperhill (ie. wet clean) cleaning system. It was my preferred method for a long time, till I started using the sticky gel pads things.
Because of the baked in syndrome tho, the gel pads system is about 99.9% effective, but sometimes you can get one spot that simply won't move at all .. ever without the wet clean.
The first thing about cleaning the sensors that people don't like is the scary nature of touching the sensor!
Unless you're a total clutz, it's actually hard to do any damage. You don't touch the sensor, you swab it with an appropriate material using a cleaning fluid. I think it's harder to DO any damage than it is not too.

Hope that helps.

thegrump
31-03-2017, 4:01pm
Thanks All................Off to get some gel sticks. I did watch a video on Utube, about the gel sticks. So am ready to go...When I can get there. Any brand preference.

arthurking... quote "The dust isn't on the sensor, it's on the filter that sits on the sensor"....so why are we cleaning the censor. :lol:
Will give Mary Anne's .... method the first try.

Mary Anne
31-03-2017, 5:39pm
You cannot just go and buy Gel Sticks you have to get them on line, if you decide to buy one try on this link http://www.fishpond.com.au/Electronics/Sensor-Gel-Stick/5060336035164
This is from the Sponsors link up top of the page as they are one of our Sponsors and every little HELPS to keep this great Forum going.

PS Just blowing the dust off using a Can of Air will not clean it perfect it will just blow off the loose dust, not the dust that is stuck there.

Hawthy
31-03-2017, 7:47pm
Found this link to buy cleaning kits on the AP sponsors' page http://shop.cameracheckpoint.com.au/

thegrump
31-03-2017, 8:57pm
Well it loos like I have some cleaning to do....