Some more tent practice, now I have a camera question

[Brian Effinger]

Ok, so I set the tent back up tonight and I used my tripod and good camera (Canon 10d w/ Tamron XR Di 28-75mm / F-2.8). I played around with the lighting, the position of the piece, the camera & tripod, and even the amount of fabric in front of the bulb. I ended up with two dozen pictures.


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So I took the memory card and downloaded the photos on my computer, and pull them up to look at them.


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CRAP!!! :mad: There is dust in all of the shots. :mad:
Now when I took the camera out of the bag, before I used it, I cleaned the lens and UV filter. The filter was pretty filthy, so I used this Purosol spray stuff & microfiber cloth that I use for cleaning my LCD screen. I lightly sprayed and wiped both sides. After it dried, I took a large cloth (the orange one from the camera shops) and using my breath, I cleaned it some more. Then I cleaned the outer glass of the lens with my breath and the same orange cloth. I then blew a little compressed air over both the filter and lens.

They both looked clean to me, so it was a totally frustrated shock to see the dust in the photo. That was the point when the little voice inside my head turned into Milton Waddams: Excuse me, senor? May I speak to you please? I asked for a mai tai, and they brought me a pina colada, and I said no salt, NO salt for the margarita, but it had salt on it, big grains of salt, floating in the glass... Since it is after midnight here, I have decided to call it quits and try again tomorrow.

So, to all of the camera guru's out there (I'm looking at you Brian Brown), what is your regimen for cleaning your equipment? I've never been a good window cleaner, so I would appreciate any tips and tricks.

Thanks for putting up with more rambling. :)

Brian

[Glenn Vaughn]

I suspect that it is not dust on the expsoed lens - rather it is either on the sensor or the back of the lens.

Take a picture of a white sheet of paper with another lens. If the dust is still there it is not the lens at all.

If it is the sensor, seek professional advice before attempting to clean it. Or - have it cleaned at a camer shop.

[Josh Reet]

Could be dust on the sensor. A common problem with DSLR's. And the 10D is old enough that it doesn't have a "self cleaning" sensor. I would hunt around on this site for info on sensor cleaning methods:

http://photo.net

A way around it until you get your sensor clean would be to try shooting with a larger aperture (smaller f-stop number). Sensor dust shows up much worse when using f16-22 than it does with f/2.8-8 or so.

Or you could just do what many of us do when we don't want to reshoot something like that...fix it in photoshop.

[Dick Sowa]

While unrelated to the dust, I think you were too close to your subject...notice the best focus is below the front rim, but the front and back rims are slightly out of focus. One fix to that is to move the camera back, so you are say, 5-6 feet (or more) from your tent, and use the zoom to close in on the bowl. Depth of field then (at any F stop), should be enough to keep the whole bowl in focus.

[Don Kondra]

http://www.lenspen.com/

Cheers, Don

[Roland Falk]

It's definitely on the sensor. Cleaning a sensor can be done - very carefully-
Check out this site -
http://www.cleaningdigitalcameras.com/methods.html
I use the Sensor Swab™ and Eclipse™ has worked for me for years , just don't use too much of the Eclipse.

DO NOT use canned air- to much chemicals in there,
on this site they have a great anti-static blowing brush.
http://www.visibledust.com/

Why, you may ask do I know so much about dust - I work as a professional photographer/producerand been dealing with cameras and dust for a long time.
hope this helps

[Brian Brown]

So, to all of the camera guru's out there (I'm looking at you Brian Brown), what is your regimen for cleaning your equipment? I've never been a good window cleaner, so I would appreciate any tips and tricks.

Brian

Way to call me out Brian. Josh and Roland nailed it. The dust is on your camera sensor, and the smaller aperature you use, the more in focus the dust becomes. Very frustrating when you need a smaller aperature to get the necessary depth of field. Makes you just want to hang it up, however, thre are solutions. Cleaning the dust sensor is not that difficult, but it is nerve recking when you know you are phisically touching the single most important and expensive part of the camera to do it. There are some good cleaning systems out there, and you got links to some of them. The system I use was made by a Canadian company called Visable Dust. I think they are out of business now (grumble cuss swear). Look into these, and what ever you do protect the brush and it's bristles. Never touch them with your fingers because the skin oil will get on your sensor. The instructions that come with them will explain their use better than I ever could.

One solution for stuff you post on the web is to step back, shoot your subject smaller in the frame, use a wider aprerature, and crop the images for final use. the D10 has resolution to burn for web shots (not so for printing). The wider aperature makes the dust show less, and the distance creates an "automatic" greater depth of field. If you zoom in on your subject you don't get the same effect, because increasing the focal length does away with that automatic increase of depth of field. I don't know how well I explained this. My physics of light and optics class was a very long time ago.

Really this is only a temporary solution, and you should get the sensor cleaned. I worry about taking it to just any camera shop for cleaning. So often the employees are minimum wage off the street people, and I question whether they know how. It is like the Borg; one great employeee, and the rest.....? It is a common problem, so learn to do it yourself. To keep the dust off, keep your lens changing to a minimum, reduce the time a lens is off the camera, and when the lens comes off, cover the opening very gently with your hand. Wind movement or jarring will just knock dust loose. Never blow anything into the mirror box, or try to wipe the box. It will just knock embedded dust off and spread it around. Also nover use a vacuum. It causes static, can pull parts loose inside the mirror box, and it just doesn't work.

Don't know how much help this is, but good luck anyway.

[Jeff Bratt]

Others have pointed you in the right direction. Photographers have always had to deal with dust. With digital sensors, it's just a different set of problems. Anytime you take pics with a small aperture, dust can show up in the frame, especially in those places that are uniform color - like your background, or the sky. The spots are there in other pictures also, it's just that if aperture is larger, or the rest of the image hides the dust spot, then you don't see it.

You should learn to clean your sensor. Even if you get it cleaned elsewhere, it will need cleaning again. The site previously referenced - Cleaning Digital Cameras (http://www.cleaningdigitalcameras.com/index.html) - has lots of good information. I follow their procedures, using equipment recommended on their site. Use the cleaning processes in order of increasing aggressiveness:
1) blow off sensor
2) brush off sensor
3) wet swab sensor
After each step, check to see if the dust problem is gone. I have yet to need step 3 on my camera - but I am prepared. If I am on day 3 of a two week trip, trying to get someone else to handle my dust problem is not a good option. YMMV.

[Scott Conners]

One of the safest and simplest ways to clean your sensor is just by blowing with a squeeze bulb blower. The Giotto rocket blower series are popular, and when I got mine I found I have to do a contact "wet" clean far less often.
Use it to blow out the mirror box of the camera and the back of the lens as often as you can (every lens change if you're unhurried). Hold the camera opening down so the dust has somewhere to go. This helps a lot, as there is far less dust to migrate to the sensor when the shutter opens.
To actually clean the sensor, check the cameras manual to find the setting that lets you lock the mirror up and the shutter open. Then blow it out the same way.

Also, always use back caps on your lenses and on your camera body when they aren't attached to each other.

[John Sheets]

I'd also eliminate the UV filter. You don't need it, it's two more air/glass interfaces to cause distortion, and also to collect dust.

[Brian Effinger]

Thanks for all of the input guys. You were all right - it was the sensor. While I only have one lens for this camera, I fortunately still had my old film canon rebel and lens up until an hour ago (I sold it on ebay this weekend for a sad price, but that's another story), so I tried that lens, and sure enough, DUST. Canon's manual says to only use a bulb type blower - no brushes, so I think I'll try that first.


One solution for stuff you post on the web is to step back, shoot your subject smaller in the frame, use a wider aprerature, and crop the images for final use. the D10 has resolution to burn for web shots (not so for printing). The wider aperature makes the dust show less, and the distance creates an "automatic" greater depth of field. If you zoom in on your subject you don't get the same effect, because increasing the focal length does away with that automatic increase of depth of field. I don't know how well I explained this. My physics of light and optics class was a very long time ago.

That does make sense and I will try that. I did notice that the dust was less visible at F/16 than at F/32. I do remember all of these rules from back in high school and college, but trying to get them straight and coherent doesn't always work with so much other stuff rattling around up there. ;)


Really this is only a temporary solution, and you should get the sensor cleaned. I worry about taking it to just any camera shop for cleaning. So often the employees are minimum wage off the street people, and I question whether they know how. It is like the Borg; one great employeee, and the rest.....? It is a common problem, so learn to do it yourself. To keep the dust off, keep your lens changing to a minimum, reduce the time a lens is off the camera, and when the lens comes off, cover the opening very gently with your hand. Wind movement or jarring will just knock dust loose. Never blow anything into the mirror box, or try to wipe the box. It will just knock embedded dust off and spread it around. Also nover use a vacuum. It causes static, can pull parts loose inside the mirror box, and it just doesn't work.

Don't know how much help this is, but good luck anyway.

I do understand your concern about blowing the dust around, but I might still try to gently blow it out tonight, and then order this (http://www.amazon.com/Digital-Survival-KIT-Sensor-Eclipse/dp/B001F1TN9M). I am a little nervous touching the sensor, but I think I can pull it off. I just need to be careful.

[Neal Addy]

Dust bunnies! Don't worry, we all get them.

You've gotten good advice. Also be sure and order a Giotto Rocket (http://www.amazon.com/Giottos-AA1900-Large-Rocket-Blaster/dp/B00017LSPI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1263948839&sr=8-1). They're handy for all kinds of situations, including a quick dust-off of your sensor. It won't get the tough cases but it will take care of the "between-cleanings". I carry a small one in my bag and keep a big one at the house.

[Brian Effinger]

Thanks Neal. I think I'll order that with a cleaning kit. And thanks for the tutorial on your website. It helped a lot. :)

I did try to blow the dust off tonight, with mixed results. It did get some of it, but not all. I was just using one of those cheap plastic bulb blowers with the crappy brush removed. It's just a lazy night here, so I didn't set up the tent and try out Brian's suggestions on setting the camera back and using a wider aperture. Maybe tomorrow.

Brian

[Jeff Bratt]

I did try to blow the dust off tonight, with mixed results. It did get some of it, but not all. I was just using one of those cheap plastic bulb blowers with the crappy brush removed.

Those little brush blowers and a rocket-sized blower should produce very different results...

[Mickey Turnbo]

You really want to test your camera for dust on the sensor? Set the aperture to a very small opening like f11 or f22. Go outside and take a picture of a clear blue sky (you may need to manually focus). If there's dust on the sensor it will POP out like crazy. One alternative, although a temporary fix, would be to process the file with software and clone out the dust spots.