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Can dirt on a lens cause flare?


Craig Lamson
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In another thread, Faked Apollo Photos, it has been suggested by Jack White and Duane Daman that dirt on a lens could not cause the effects shown on this and other Apollo photographs:

a14-64-9089.jpg

White has claimed the reduction of contrast in the black sky is caused by studio light reflecting off of a background. I claim dirt on the lens is the cause.

So to that end I decided to test. I created a simple studio set with a single spotlight as lightsource, a black background and a single prop. I set up a Canon 1DsMKII digital camera and mounted a Nikon zoom lens and set it to 50mm. The spotlight was behind and to camera left. Light from the spotlight illuminated both the subject and it was also striking the lens.

setup.jpg

I then exposed a frame. In this image the lens was perfectly clean. Notice the standard lens flare from the left side of the frame, which indicates the light was indeed striking the lens. Also notice the deep black background to the right side of the frame.

nodirt.jpg

To attempt to recreate the effect seen in the Apollo image I took some fine dirt and dust from the studio floor and tossed it at the front surface of the lens. :

lens.jpg

I then took another frame. The only difference between this frame and the other is the dirt on the lens. Notice the lens flare all over the frame. Pay special notice to the black background on the right side of the frame. There is large loss of contrast and a flare type shape that is very similar to the Apollo image.

dirt.jpg

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In another thread, Faked Apollo Photos, it has been suggested by Jack White and Duane Daman that dirt on a lens could not cause the effects shown on this and other Apollo photographs:

<snip>

Persuasive stuff.

I can hear the counter-arguments now. "That looks nothing like the Apollo photo! I want it recreated exactly!" You've proved the principle: dust on a lens can cause lens flare and reduce contrast. That more than amply explains the effect seen on the Apollo photos.

There's also the empirical evidence that the dusty zones in the Apollo photos appear in the same areas of the frame from one photo to the next. If this was a light on a background this wouldn't be the case.

The available evidence supports dust on a lens causing the effect. There is evidence directly negating the "light on a background" theory. Conclusion: there was dust on the lens (and as you rightly pointed out Craig, they provided later missions with the means to clean their lens to mitigate this problem).

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Can Jack or Duane rebut this? No "He is an Apollogist" or "Typical disinformation from Lamson" - just PROVE that what Craig has done is flawed or incorrect. Simply point out where his errors lay, if any. Don't forget to support your rebuttal. Simply saying "WRONG!" does not mean anything unless you can demonstrate why it is wrong.

Proof - plain and simple.

Attack the argument, not the poster.

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So to that end I decided to test. I created a simple STUDIO SET with a single SPOTLIGHT as lightsource, a BLACK BACKGROUND and a single prop. I set up a Canon 1DsMKII digital camera and mounted a Nikon zoom lens and set it to 50mm. The SPOTLIGHT was behind and to camera left. Light from the SPOTLIGHT illuminated both the subject and it was also striking the lens.

I do believe the words I put in caps are enough of a rebuttal . LOL

I'm sorry , but craig's picture hasn't proven that "lens flare" is what caused the light reflection in the Apollo photo ... All it's proven is that he has a nice big studio ...and you're correct Dave ... "That looks nothing like the Apollo photo" .... IN ANY RESPECT !

If you believe that dirt on the camera lens caused the reflection and that the Luanr surface covered everything in moon dirt , including the camera lenses , then why didn't all of the photos have "LENS FLARE " !?!?!

Talk about "masters" and follwers .. You seem to have some devoted followers yourself Lamson ... Especially considering how quickly they jumped on something as pathetic as this lame demonstration is .

Edited by Duane Daman
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So to that end I decided to test. I created a simple STUDIO SET with a single SPOTLIGHT as lightsource, a BLACK BACKGROUND and a single prop. I set up a Canon 1DsMKII digital camera and mounted a Nikon zoom lens and set it to 50mm. The SPOTLIGHT was behind and to camera left. Light from the SPOTLIGHT illuminated both the subject and it was also striking the lens.

I do believe the words I put in caps are enough of a rebuttal . LOL

I'm sorry , but craig's picture hasn't proven that "lens flare" is what caused the light reflection in the Apollo photo ... All it's proven is that he has a nice big studio ...and you're correct Dave ... "That looks nothing like the Apollo photo" .... IN ANY RESPECT !

If you believe that dirt on the camera lens caused the reflection and that the Luanr surface covered everything in moon dirt , including the camera lenses , then why didn't all of the photos have "LENS FLARE " !?!?!

Talk about "masters" and follwers .. You seem to have some devoted followers yourself Lamson ... Especially considering how quickly they jumped on something as pathetic as this lame demonstration is .

Once again your ignorance comes to the forefront.

Please elaborate on why you think your bolded words form a "rebuttal." Please provide DETAILED specfics and include empirical photographic evidence to back up your claims.

Why do all of the Lunar photos not have dirt-induced lens flare? Because not all of them were taken with light striking the lens and during the later missions care was taken TO CLEAN THE LENSES.

Your reply is LOL for sure.

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Putting CAPS on those particular words was a joke , which apparently went right over your head , as you obviously have no sense of humor . :)

The only thing your picture has proven is that you are a master game player and will resort to any means to try to disprove Jack .. and to also try to prove that the Apollo photos aren't studio fakes .

Later missions "CLEANED THE LENSES "..... LOL for sure .

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I'm sorry , but craig's picture hasn't proven that "lens flare" is what caused the light reflection in the Apollo photo ... All it's proven is that he has a nice big studio ...and you're correct Dave ... "That looks nothing like the Apollo photo" .... IN ANY RESPECT !

He demonstrated the principle that dust on a lens causes lens flare and reduces contrast. Quite a simple demonstration, and not too difficult to understand.

If you believe that dirt on the camera lens caused the reflection and that the Luanr surface covered everything in moon dirt , including the camera lenses , then why didn't all of the photos have "LENS FLARE " !?!?!

Many of the Apollo 12 photos did. I provided links to them in this thread. Since you were too busy dishing out early Christmas presents to everyone you may have overlooked them, so here they are again especially for you, 15 photos from Apollo 12 showing dust on the lens. As pointed out, this only becomes visible when sunlight directly strikes the lens, another concept I'm sure you'll agree is very simple to understand.

AS12-49-7198

AS12-49-7201

AS12-49-7202

AS12-49-7223

AS12-49-7233

AS12-49-7247

AS12-49-7248

AS12-49-7249

AS12-49-7261

AS12-49-7262

AS12-49-7283

AS12-49-7294

AS12-49-7295

AS12-49-7300

AS12-49-7301

The camera obviously got very dusty, as you can see in this detail of AS12-49-7278 (ignore the red circle - that was to highlight the reflection of the astronaut for the other study). Here's the full-size hi-res version for comparison.

as12-49-7278-lens-reflection.jpg

So what have we got?

1. Empirical proof that dirt on the lens can cause lens flare - check.

2. Evidence that moon dust did indeed get "just about everywhere" - check.

3. The simple concept that the sun needs to strike the lens directly to cause the flare - check.

4. Knowledge that subsequent missions did indeed clean lenses with dust brushes (not just the Hasselblads but also the TV camera) - check.

Source

[bean, from the 1969 Technical Debrief - "I would like to say something about the camera. We got a lot of dust on ourselves and also on the outside of the camera. We kept looking at the lens to see if there was any dust on it and to see if it was going to degrade the pictures. Neither Pete nor I could see it on each other's camera (lens), although the other parts of our cameras were covered with dust. We'll have to take a look at the pictures that we returned (which look okay). If it does turn out to be a problem, we're going to have to come up with some sort of brush we can use to dust off the lens, because I don't see any other way (to clean them). We were trying our best to keep the equipment clean; but just moving around, trenching, leaning over, and all the other things tend to get dust on the equipment."]

[Later crews tended to be even more active than Pete and Al and, consequently, fell more often and otherwise covered themselves and the cameras with dust. They carried a small, soft-bristle brush for lens cleaning and regularly put it to use on the Hasselblads and on the Rover TV.]

5. Dust appears in same regions of images, verifying it's unlikely to be light cast on a backdrop - check.

Do you have anything other than rhetoric?

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Do you have anything other than rhetoric?

Yes , I do ... A big pile of faked Apollo photos full of anomalies .

I take your refusal to address the evidence in my post as a no then!

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Do you have anything other than rhetoric?

Yes , I do ... A big pile of faked Apollo photos full of anomalies . Gross ignorance

There ya go - I fixed it for you.

There ya go is right ... and I PMed you not long ago Evan , telling you that I thought you were a fair moderator doing a good job here ... My mistake .

Dave ... I will check out your evidence later when I have more time and post a more detailed reply then .

Edited by Duane Daman
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Do you have anything other than rhetoric?

Yes , I do ... A big pile of faked Apollo photos full of anomalies . Gross ignorance

There ya go - I fixed it for you.

There ya go is right ... and I PMed you not long ago Evan , telling you that I thought you were a fair moderator doing a good job here ... My mistake .

Dave ... I will check out your evidence later when I have more time and post a more detailed reply then .

For once I find myself in agreement with Duane - I think you may have slightly over-stepped the mark Evan old boy. I too think you've done a fine job navigating the murky waters faced by moderators (who also have an opinion on the topic up for debate), but that was a little naughty IMO.

However Duane... I have a lot of sympathy for Evan because of your debating style. Time and again detailed rebuttals, and empirical evidence just gets waved away with accusations of mind-games, disinformation, NASA nonsense, rather than responding to the actual evidence presented. You refuse to listen (or at least that's the impression you give) to rationally made arguments, backed up with research and evidence.

Evan may have sounded a bit harsh, but by your own admission you know little about photography and less about science/maths - so strictly speaking he's right, as you are ignorant of these topics. To cap it all you seem unwilling to educate yourself about them.

I was thoroughly ignorant of photography a few years ago, that's why Percy's stuff initially intrigued me (it's very good at ensnaring the unwary). The more you learn about photography, the more you realise how flawed his (and Jack White's) arguments re photography are. If you really wanted to, you could educate yourself about these things as well, then you'd know WHY they are wrong, rather than just accepting what they say at face value because you agree with their conclusions. I suspect that's why people accuse you of being ignorant - not just your lack of knowledge, but your apparent lack of desire to learn.

Mind you, what he said was small beer compared to some of the unwarranted attacks you've made on this forum to many people, so don't get on your high horse just yet!

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My "unwarrented attacks" are defensive blows against insulting , game playing , members here who will do whatever it takes to 'win' their argument .... So if my debating style seems a bit harsh to you , that would be the reason...and I only dismiss evidence that I don't believe has much merit to it , not because I haven't bothered to read it .

I have read every post that you and lamson have written about photography and have learned a lot about the subject ... I have also learned that neither one of you are capable of ever admitting that you might be mistaken about the validity of every single Apollo photo.. and now I understand why it's so important for you to win this argument ... and it has also become very clear why I am wasting my time arguing about it with you ... Your minds are made up that Apollo was real and that the Apollo photos were really taken on the Moon ...So because of that , neither one of you knows how to be objective about this subject or open to the idea that nasa faked some , if not all of their Apollo photos ..

I have no doubt that the Apollo photos are fakes ... In fact many millions of people can see they are fake ... but there are many people who can't or won't see this , for whatever reason . ..It might have a lot to do with preconceived beliefs or certain mindsets or because you have been led to believe that anyone who doubts the official Apollo record is a " nutjob" etc. ... but whatever the reason, it's a fact that we will never agree on this subject ... and as we once said in PM's to each other on YouTube , it really is pointless to continue arguing about something which can't be proven one way or the other ... I see a stage light reflection in a visor , you see a smudge ... I see a painted, fake backdrop on a moonset , you see mountains on the Moon ... and round and round it goes ... So I guess we will just have to agree to disagree once more .

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