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10/10/2005 03:13:42 PM · #26 |
Originally posted by jonr:
Originally posted by leaf:
here is my dust on my sensor.. have never cleaned it :S .. i am scared to.
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:( That is nasty!!! |
have you tested your lens? with the handy dandy, jacko method (i think it was him)
take a picture of a white wall with the flash, stopped down.
then open it up in photoshop, and click 'auto' in the curves.
SURPRISE.... :) |
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10/10/2005 03:51:27 PM · #27 |
Originally posted by ShorterThanJesus:
"Why would you have to use f22 just to avoid overexposure, unless you are looking to use a specific shutter speed?"
I like to have the freedom to use what is available. I don't have a ND filter yet so I'm left to juggle aperature and shutter speed to get the desired effect (ie. blur of a waterfall midday).
Define CA? |
Sorry, probably didn't really mean CA (Chromatic Aberration), I wasn't thinking too hard at the time. I should just have said that you might end up with soft images, due to diffraction at such small apertures.
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10/10/2005 06:19:20 PM · #28 |
There was a thread some days ago on how to find out if there is a lot of dust on your sensorHere is the thread
A couple of people in the current thread have talked about the same method but it seems to be incomplete as compared to the thread i'm mentioning...
Blackdot mentioned to do this (in teh above thread):
1. Take a pic of something plain white like a fridge or a wall
2. F22, manual focus to infinity (I guess this is to remove any texture from the surface)
3. Use the flash, but watch out for reflections.
4. Load in Photoshop and hit Auto levels.
5. Now move the right slider in levels over to the left. (Very important..what this does is to completely remove any info of the pic and whatever black spots are remaining is the sensor dust )
Leaf and Jonr, from the photos you have posted, it is obvious that step 5 hasnt been performed...what you are seeing is the dust/color messup on teh surface whose photo you ahve taken not teh sensor
Hope this helps.
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10/10/2005 06:34:09 PM · #29 |
I have always shot the sky, focused close as possible, at highest apature. Then if you really want to make the nasties jump out play with the USM. Take that up above 200% and they sort of jump out at you.
I'm not clear on how sliding the white levels to black helps show sensor dust. |
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10/10/2005 06:35:47 PM · #30 |
Suprada,
If they have thrown the focus out, and it is obvious that they have, then the remaining in-focus specks have to be somewhere in the optical flow, long before the actual surface. Thus those specks are either on the lense or sensor.
All that photoshop process would do would be to make the specks stand out even more. It would benefit the clarity in the photos we posted but the specks are definitely in/on the camera, not on the surface.
Message edited by author 2005-10-10 18:39:00. |
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10/10/2005 07:01:38 PM · #31 |
Jon,
After reading your post and thinking about it, I realize what you does sound right. I guess the step 5 is optional...Let me try to explain why I thought it was essential:
When I tried to find the dust in my senor, my image without step 5 had more spots than the image after step 5. Trying to get an out of focus image, will nevertheless leave some kind of background/texture/weird bokeh-like stuff (sorry..cant explain better).
When the rightmost slider in levels is slid to the left, you're pretty much saying that anything other than the darkest colors (black, very dark blue, very dark green etrc) are made to white. Now, if you start with a brightly colored picture, only the blacks will be left at this point. If you take an almost white picture or grey picture, all that will be left are the points of dirt on thh camera and sensor...those dirty spots due to the dirty surface (grey spots on a grey picture) will vanish giving you a more accurate picture of the sensor + lens dirt.
Hence my requirement of step 5.
Suprada
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10/10/2005 07:22:33 PM · #32 |
Originally posted by leaf:
here is my dust on my sensor.. have never cleaned it :S .. i am scared to.
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time for some ACNE medication! That is nasty leaf :) |
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10/10/2005 08:08:34 PM · #33 |
Clean that thing.....I clean mine about once a month if necessary. I use that swab thing and cleaning fluid found on the internet. I forget the name of it but I'm sure someone will know.
I have a D70 and usually have no dust after one or two swabs!
Kenskid
Originally posted by leaf:
here is my dust on my sensor.. have never cleaned it :S .. i am scared to.
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10/10/2005 09:25:58 PM · #34 |
Thanks for all of the help. It is appreciated (good advice on the PS step Suprada).
Any other advice for generally keeping this beasty reasonably clean would be appreciated. I know how to wipe it, and will be getting a bulb very soon, but I would love (of course) not to have this incorporated in to my daily routine if at all possible. |
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10/15/2005 08:53:01 AM · #35 |
Originally posted by Azrifel:
Altough I know there is some dust on the sensor I haven't cleaned it yet |
One year of ownership, lots of lens changing and on the dust pic I shot today there is one major bit of dust 10x10px and twenty really small ones between 2x2 and 6x6 px. It looks surprisingly clean.
- avoid dusty areas when I change the lens
- I blow the rear elements, the protection caps, the lens mount before I switch lenses
- I switch them as fast as possible, the mirror box is exposed for perhaps 5 to 10 seconds if not less
The more annoying thing is that I see a little hair in my viewfinder and it is not on the lens, mirror or mirror-side of the prisma. Probably behind the viewfinder glass. Have to check how to take that out. :(
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10/15/2005 09:33:34 AM · #36 |
| thanks for the tips guys.... had my 350d since the week it came out, did the test and noticed maybe 2 visible specs but i'm obsessive about trying to keep dust out when i change lenses. |
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10/16/2005 08:13:29 AM · #37 |
It can be an obsession.
I use the Cotton bud method. It generally works and once it is clean it should stay clean for a while. It is a problem though that should be addressed by the manufacturers. I even got to the point where i didnt want to change lenses in fear of getting the horrible looking spec.
The shop i bought it from advised to change lense as little as possible?????????????
Now though i change them when i need to, if a spec appears normally a quick blow with a bulb works if not i edit them out until it builds up enough for me to want to bud it.
Be careful of the bulbs though, put your finger over the hole on the top as if you dont the bulb sucks in the dust in the room through it and virtually welds it to the sensor. This then requires it to be cleaned again. |
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10/16/2005 09:09:55 AM · #38 |
| When I got my D70s I had dust on the sensor after a few days already. I cleaned it twice, and since then haven't had to clean again (yet :-), although I do change lenses quite often. |
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10/16/2005 09:59:08 AM · #39 |
I had a rebel for close to a year, and no dust at all, ever. Dust showed up on my d70 after about the first day...and continually increases consitently...I can't explain why the rebel didn't get dust and the d70 does, but you're definately not alone. I just leave the dust until it gets too bad...sometimes when I change the lens, I blow around the lens before I take it off to make sure there is no dust sitting there ready to go in, then blow inside lightly to try and move some of the dust, but that never works.
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10/16/2005 11:11:51 AM · #40 |
I didnt have to clean my rebel's sensor for months after I got it, now i've had my 20D for just a couple of months and I already need to clean it. I guess it's just on a camera by camera basis.
June
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10/16/2005 11:18:58 AM · #41 |
When we first got our Nikon D70 we didn't have to clean it for a long time, we simply weren't finding much sensor dust at all. Only after a trip to Antarctica did we pick up lots of crap on the sensor and got it cleaned professionally. We also picked up a home cleaning kit that we've occasionally used.
Same for the 20D, we've not had much issues with it either, we've cleaned it once or twice in the several months since we've owned it and that's after some trips to some fairly harsh environments including the Antarctic and Peru.
It seems like your sensor is attracting more dust than it should and I can't imagine why.
If it's brand new I'd ask for a replacement - maybe the sensor is unusually charged even when the camera is off (or retains a charge for longer than it should after it's switched off) or something weird.
Message edited by author 2005-10-16 11:21:53.
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10/16/2005 11:22:51 AM · #42 |
Pete wondered if there's a crack in the body - a failure of one of the seals?
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10/16/2005 11:22:56 AM · #43 |
| I've heard that CCD sensors attract more dust than the CMOS kind. |
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10/16/2005 11:38:37 AM · #44 |
Originally posted by Olyuzi:
I've heard that CCD sensors attract more dust than the CMOS kind. |
We have both the Canon 20D and the Nikon D70 and have taken both on trips to the Antarctic as well as some pretty dusty places in Peru, together with normal use here in the UK. We've not noticed one of them attracting dust more than the other ourselves.
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10/16/2005 11:43:27 AM · #45 |
Sensor dust is a fact of life with DSLR's, and cleaning it is a 2 min job...I usually clean it before and after a big day of shooting.
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10/16/2005 12:07:00 PM · #46 |
Originally posted by doctornick:
Sensor dust is a fact of life with DSLR's, and cleaning it is a 2 min job...I usually clean it before and after a big day of shooting. |
Not true with Olympus DSLRs. There is NO dust accumulation on their sensors and no cleaning required. |
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10/16/2005 12:44:49 PM · #47 |
| you really dont want to clean the CCD yourself you should probebly send it to Nikon it takes about a week and cost between 50 to 100 bucks. My thought is that you can always clone out the dust spots in photoshop you had to this same process with film it is just a fact of photography. This is something that you really cant get around as a photographer. we live in a dusty world and we need to practice the technique of fixing it post process, that is what makes us professionals. |
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