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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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 Posted: Tue Mar 17, 2009 4:36 pm Post subject: How Much Dust is TOO Much? |
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Laurence wrote:
I was looking through a magnifying loupe at a lens with some fungus around the periphery this morning.
Thankfully, it looks like the fungus has not etched the surface, and is still confined to a thin edge.
I noticed also a lot of dust in the lens, so I started picking up my other lenses...holy cow! There sure is a lot of dust in ALL of them!
But perhaps it's just because I only usually just hold a lens up to the light with my eye, and I don't see the totality of the dust particles.
But looking through a loupe at a white computer monitor, it is like a FIELD of dust!
My question is: are my lenses ALL really that bad with dust, or is this sort of "normal"?
I guess my best description of the dust that I'm seeing is: pretend you have drawn a 1-inch diameter circle on a piece of paper.
Then take a pencil and tap "dust spots" onto the paper.
I would say that some of my lenses have maybe 20 "dust marks", but others have up to 50 or more! 
Almost looks like a CONSTELLATION of dust particles and other little
things like tiny hairs and splotches.
Is there a point when I should be concerned about image integrity?
And a side question: I wonder what's in our LUNGS!
Thanks as always.
Laurence
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
Last edited by Laurence on Tue Mar 17, 2009 4:40 pm; edited 1 time in total |
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Orio
Joined: 24 Feb 2007
Posts: 29545
Location: West Emilia
Expire: 2012-12-04
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| Posted: Tue Mar 17, 2009 4:39 pm Post subject: |
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Orio wrote:
I guess the most damage dust specs can make is to scatter light around and reduce contrast. But I guess you would really need a lot of dust for that to become visible.
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Tue Mar 17, 2009 4:41 pm Post subject: |
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Laurence wrote:
| Orio wrote: |
| I guess the most damage dust specs can make is to scatter light around and reduce contrast. But I guess you would really need a lot of dust for that to become visible. |
Any idea of how much might be too much? Or is it simply a sort of "guess", and to just try to see if there is some change in contrast?
It sounds like I just shouldn't worry about it until I somehow feel that the lens is degraded.
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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no-X
Joined: 19 Jul 2008
Posts: 2495
Location: Budejky, Czech Republic
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| Posted: Tue Mar 17, 2009 4:46 pm Post subject: |
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no-X wrote:
I never saw a lens, which performance would be affected by dust. Differently colored MC layers has more significant impact, than dust 
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Tue Mar 17, 2009 4:59 pm Post subject: |
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Laurence wrote:
Thanks Orio and no-x....I feel better.
Now I need to go get the vacuum cleaner and stuff the hose down into my lungs to get the dust out that MUST be in there.
I'll let you know how that turns out! 
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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Orio
Joined: 24 Feb 2007
Posts: 29545
Location: West Emilia
Expire: 2012-12-04
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| Posted: Tue Mar 17, 2009 5:09 pm Post subject: |
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Orio wrote:
| Laurence wrote: |
| Orio wrote: |
| I guess the most damage dust specs can make is to scatter light around and reduce contrast. But I guess you would really need a lot of dust for that to become visible. |
Any idea of how much might be too much? Or is it simply a sort of "guess", and to just try to see if there is some change in contrast?
It sounds like I just shouldn't worry about it until I somehow feel that the lens is degraded. |
Well... let's start to say that the closer to the back glass, the noisier. Dust on the front glass is likely to be irrelevant. Dust in the back of the lens can affect contrast more visibly and even become visible at the smallest apertures, especially if the lens is a wide angle.
I would be cautious to say that dust can never affect performance. Chances are the effect will be irrelevant in most cases, but it really depends on how much dust and also on how reflective. Dark dust is almost certain to go unnoticed. White bright dust might affect. When a lens is really full of dust I think it's likely that the contrast might be reduced. I once was sold a lens with fungus behind the front glass. It was a Distagon 1.4/35. The fungus was almost invisible at naked eye due to the multicoating. It was also irrelevant wide open. However, when stopping down the lens to f/11, the blots of the fungus became recognizeable in the pictures, even if that was on the front lens.
So it is really a case by case thing.
I think that we can generally say that dark dust is better than white dust, and tele lenses suffer much less than wide angle lenses.
In any case, if the lens is a valuable one, I would certainly have it serviced to remove dust.
It will do the lens good, even if just on the preservation side and on the resale value side.
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visualopsins
Joined: 05 Mar 2009
Posts: 11019
Location: California
Expire: 2025-04-11
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| Posted: Tue Mar 17, 2009 5:29 pm Post subject: atmospheric dust levels on the rise |
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visualopsins wrote:
West Coast North America dust levels are high in large part due to increases in coal-burning and other industrial pollution from east asia blown here by tradewinds and jetstreams. Increased worldwide volcanic activity has poured a lot of dust into the atmosphere too.
Maybe because I'm overly sensitive or because I live in an otherwise pristine environment, I've noticed increasing atmospheric dust levels the past 5 years or so. Sometimes the dust seems to have toxic effects, such as drowsiness and general malaise.
Where I live with onshore breezes from 3000 miles of open ocean it seems like the air should be relatively dust free; at night a headlamp reveals a LOT of dust in the air. A back-burner project of mine is to capture dust on sticky tape and look at it closely through the microscope; is it mineral, pollen, what?
The dust is very fine, and gets into lenses and sensors easily.
I hate to say it but it sounds like fungus is starting to grow on the dust in your lenses due to high humidity. as mycologists say "when it rains, it spores" and your area, like mine, at times measure rainfall in feet (it has rained 1'2" here in the past three days).
I have too many older lenses that cause me to worry about fungus, so I keep them all in pelican cases with dehumidifiers and gauges; so far so good! That's storage; I also have a similarly equiped peli used to "dry" lenses fresh from the field, before transferring to storage pelis.
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Lenses:
M42 Asahi Optical Co., Takumar 1:4 f=35mm, 1:2 f=58mm (Sonnar), 1:2.4 f=58mm (Heliar), 1:2.2 f=55mm (Gaussian), 1:2.8 f=105mm (Model I), 1:2.8/105 (Model II), 1:5.6/200, Tele-Takumar 1:5.6/200, 1:6.3/300, Macro-Takumar 1:4/50, Auto-Takumar 1:2.3 f=35, 1:1.8 f=55mm, 1:2.2 f=55mm, Super-TAKUMAR 1:3.5/28 (fat), 1:2/35 (Fat), 1:1.4/50 (8-element), Super-Multi-Coated Fisheye-TAKUMAR 1:4/17, Super-Multi-Coated TAKUMAR 1:4.5/20, 1:3.5/24, 1:3.5/28, 1:2/35, 1:3.5/35, 1:1.8/85, 1:1.9/85 1:2.8/105, 1:3.5/135, 1:2.5/135 (II), 1:4/150, 1:4/200, 1:4/300, 1:4.5/500, Super-Multi-Coated Macro-TAKUMAR 1:4/50, 1:4/100, Super-Multi-Coated Bellows-TAKUMAR 1:4/100, SMC TAKUMAR 1:1.4/50, 1:1.8/55
M42 Carl Zeiss Jena Flektogon 2.4/35
Contax Carl Zeiss Vario-Sonnar T* 28-70mm F3.5-4.5
Pentax K-mount SMC PENTAX-A ZOOM 1:3.5 35~105mm, SMC PENTAX ZOOM 1:4 45~125mm
Nikon Micro-NIKKOR-P-C Auto 1:3.5 f=55mm, NIKKOR-P Auto 105mm f/2.5 Pre-AI (Sonnar), Micro-NIKKOR 105mm 1:4 AI, NIKKOR AI-S 35-135mm f/3,5-4,5
Tamron SP 17mm f/3.5 (51B), Tamron SP 17mm f/3.5 (151B), SP 500mm f/8 (55BB), SP 70-210mm f/3.5 (19AH)
Vivitar 100mm 1:2.8 MC 1:1 Macro Telephoto (Kiron)
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Attila
Joined: 24 Feb 2007
Posts: 57865
Location: Hungary
Expire: 2025-11-18
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| Posted: Tue Mar 17, 2009 5:40 pm Post subject: |
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Attila wrote:
If dust (fine powder) cover all lens surface it able to reduce contrast pretty well. Bigger dust parts even if a lot there mostly not impact anything.
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Orio
Joined: 24 Feb 2007
Posts: 29545
Location: West Emilia
Expire: 2012-12-04
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| Posted: Tue Mar 17, 2009 5:46 pm Post subject: |
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Orio wrote:
| Attila wrote: |
| If dust (fine powder) cover all lens surface it able to reduce contrast pretty well. Bigger dust parts even if a lot there mostly not impact anything. |
Yes, lots of fine dust like powder has an effect similar to those many round cleaning marks on old lenses, it reduces contrast.
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Ferrania film is reborn! http://www.filmferrania.it/
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Tue Mar 17, 2009 5:48 pm Post subject: |
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Laurence wrote:
GREAT information Orio and Sirius Dog Star and Attila...
My lenses are presently stored in a rubber-sealed China Cabinet with a large contingent of dessicators. I leave the light on in there at night, just to warm up the immediate atmosphere and to drop the humidity down.
Today, all the lenses and cameras are opened up and are sitting in the sun on a table, just to give them some bright light and warmth. I will later blow them off with a canned air duster, and have already accomplished my monthly "wipe down" of the cabinet and shelves. I guess that's about all I can do to help dissuade fungus. So far, I'm lucky.
Oh...I accomplished pushing the vacuum hose down into my lungs and getting some dust out. But, it seems that right now I have a lot of blood coming out of my nose, mouth and ears, accompanied with severe pain in my chest. Probably something I should just keep my eye on I guess. Now I'm starting to wonder if maybe that wasn't such a great idea after all...
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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Farside
Joined: 01 Sep 2007
Posts: 6557
Location: Ireland
Expire: 2013-12-27
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| Posted: Tue Mar 17, 2009 8:54 pm Post subject: |
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Farside wrote:
| Laurence wrote: |
Oh...I accomplished pushing the vacuum hose down into my lungs and getting some dust out. But, it seems that right now I have a lot of blood coming out of my nose, mouth and ears, accompanied with severe pain in my chest. Probably something I should just keep my eye on I guess. Now I'm starting to wonder if maybe that wasn't such a great idea after all... |
Amateur. Should have used an angle grinder.
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nemesis101
Joined: 25 Mar 2008
Posts: 2050
Location: Oregon USA
Expire: 2015-01-22
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| Posted: Tue Mar 17, 2009 9:14 pm Post subject: |
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nemesis101 wrote:
This is an interesting thread. I used to live in Michigan, and there if I dusted the place more than once a week it was unusual, indeed the odd missed week never showed. Here in Oregon the place (only three years old and fully double glazed / draft sealed) is FULL of dust - it seems to coat everything and removing it is a daily battle. I do have two dogs, but it can't all be animal dander as I had them in Michigan too!
The dust appears to be pollen for the most part - Oregon and the NW are known as the mold / pollen capital of the continent so??
Anyway I keep my lenses in dry conditions, in air-tight cases which are dehumidified and so far so good but...?
Doug.
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Tue Mar 17, 2009 10:35 pm Post subject: |
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Laurence wrote:
| Farside wrote: |
| Laurence wrote: |
Oh...I accomplished pushing the vacuum hose down into my lungs and getting some dust out. But, it seems that right now I have a lot of blood coming out of my nose, mouth and ears, accompanied with severe pain in my chest. Probably something I should just keep my eye on I guess. Now I'm starting to wonder if maybe that wasn't such a great idea after all... |
Amateur. Should have used an angle grinder. |
Wouldn't that hurt though? 
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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Laurence
Joined: 26 Mar 2007
Posts: 4809
Location: Western Washington State
Expire: 2016-06-19
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| Posted: Tue Mar 17, 2009 10:37 pm Post subject: |
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Laurence wrote:
Doug, it is interesting how you are experiencing a very noticeable difference in dust particles in Oregon over Michigan. I think you are probably correct about the pollen count.
And yet...the scientific world says that the Pacific Northwest coast has some of the cleanest air on earth, next to Antarctica! Go figure!
_________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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nemesis101
Joined: 25 Mar 2008
Posts: 2050
Location: Oregon USA
Expire: 2015-01-22
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| Posted: Wed Mar 18, 2009 12:25 am Post subject: |
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nemesis101 wrote:
Maybe the coast.. but on the other side of the Coastal Range? Not so sure.. certainly in my European guide of places for allergy / mold sufferers to avoid, Arizona is bottom and good old Oregon is up there at No1!
Hmm
I'll try and get the microscope out this weekend and take a look... might even try and fish out my Pentax 'scope adapter and post some pics, if I can work out the lighting!
Doug
| Laurence wrote: |
Doug, it is interesting how you are experiencing a very noticeable difference in dust particles in Oregon over Michigan. I think you are probably correct about the pollen count.
And yet...the scientific world says that the Pacific Northwest coast has some of the cleanest air on earth, next to Antarctica! Go figure! |
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Lenses and cameras:
Amateurs worry about equipment
Pros worry about money,
Masters worry about light. |
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cledry
Joined: 22 Dec 2008
Posts: 142
Location: Orlando, FL USA
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| Posted: Wed Mar 18, 2009 1:14 am Post subject: |
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cledry wrote:
I would say if you are happy with the images than why worry. Unless one is collecting lenses not to use, it is all down to image quality in the end. |
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edumad
Joined: 11 Feb 2009
Posts: 348
Location: Esposende, Portugal
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| Posted: Thu Mar 26, 2009 8:50 pm Post subject: |
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edumad wrote:
This is how my tokina looks inside. Cant notice any effect, I was amazed with the quality of the lens, but I don't like push-pulls...
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nemesis101
Joined: 25 Mar 2008
Posts: 2050
Location: Oregon USA
Expire: 2015-01-22
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| Posted: Thu Mar 26, 2009 10:14 pm Post subject: |
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nemesis101 wrote:
Blimey - I thought that was a shot of the Moon until I read the caption!
lol
Doug.
| edumad wrote: |
This is how my tokina looks inside. Cant notice any effect, I was amazed with the quality of the lens, but I don't like push-pulls...
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Lenses and cameras:
Amateurs worry about equipment
Pros worry about money,
Masters worry about light. |
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F16SUNSHINE
Joined: 20 Aug 2007
Posts: 5486
Location: Left Coast
Expire: 2011-11-18
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| Posted: Fri Mar 27, 2009 2:06 am Post subject: |
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F16SUNSHINE wrote:
| edumad wrote: |
This is how my tokina looks inside. Cant notice any effect, I was amazed with the quality of the lens, but I don't like push-pulls...
|
I have a couple lenses that look the same..........no issue
If it is just dust it's not usually a problem.
It is strange. Lenses can be hammered and work fine or have one fine scratch and be sheet.
I have a Zuiko 2/24 that has some small but quite deep scratches on the front. As in you can catch a fingernail and hold it deep.
I painted the scratches black and no problem even though the lens is a WA.
I also had a Zuiko 2.8/135 with just some cleaning marks on the front.
It caused a nasty contrast loss in high light. Fine in shade areas or well protected.
Every lens has a different capability of dealing with issues.
You never know until you try is the moral I suppose 
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