diffraction

samjNC · Mar 30, 2008

I am curious about this quote from Thom Hogan:

Closed down is soft (diffraction rears its head above f/11 on the D2xs, D3, and D300, and f/13 on the D80 and D200).

I thought a FF sensor would be less prone to diffraction, meaning you could go to f/13 or f/16 while at something like the D50 (my camera) or a D300 you woudnt want to dip much below f/11.

Also, with my D50, if I want lots of DOF, could I go to f16 and be OK? How much worse is f/11 v. f/16 or f/22 or f/32 for the D50?

DUSTY LENS · Mar 31, 2008

samjNC ,

Diffraction is caused by light rays that in some way are effected be reflecting off of the edge of the aperture blades and then landing on the sensor in the wrong place .

This is reduced in larger formats and sensors because lenses must be longer in focal length to get the same perspective with larger formats and larger sensors .

This is because a longer lens focal length will need a larger area inside the aperture opening to deliver the same f ratio . ( lens opening for the same amount of light to pass through ) .

This effects the percentage of light which passes without grazing the aperture blades compared to the amount of light which passes through but suffers the effects of diffraction by striking the edge of the aperture .

The smaller aperture , ( which is in the shorter focal length lenses used for smallerer sensors ) has more light effected by diffraction ) .

This is the same for short focal length lenses ( wide angle ) used with larger formats or sensors .

So It would seem , that at some point in time the job of the aperture should be given to a neutral density darkened thin sheet of optical glass where the aperture blades would have been .

I have thought it should be two thin sheets of optical glass with liquid crystal rings which can be darkened electronically to form an aperture opening of the size needed instantly for each exposure .

I assume liquid crystal when darkened would not behave like a metal aperture blade causing diffraction . But if it does then why not fade the edge of each ring so there is no real edge to cause Diffraction .

Another limitation with a smaller sensor is the limited range of aperture size with wide lenses ( very short focal length lenses will have diffraction limited sharpness at larger lens openings ) but they will have greater depth of sharp focus than the equivalent lens used on larger formats at the same subject distance and the same aperture setting .

This is because for example you are in a room where the subject is limited to no more than ten feet away . A large format Camera will see this as very close to the lens but a very small format camera will see this as near to infinity , and at infinity the depth of focus is nearly infinite ( very great ) .

joe mama · Mar 31, 2008

samjNC said:
I am curious about this quote from Thom Hogan:

Closed down is soft (diffraction rears its head above f/11 on the
D2xs, D3, and D300, and f/13 on the D80 and D200).

He must have been hitting the pipe a bit hard when he wrote that. : )

samjNC said:
I thought a FF sensor would be less prone to diffraction, meaning you
could go to f/13 or f/16 while at something like the D50 (my camera)
or a D300 you woudnt want to dip much below f/11.

The effects of diffraction softening scale the same way as does the FL (focal length). For example, f/10 on 1.5x has the same effect as f/15 on 35mm FF for the same level of detail .

Let's say that for a 10 MP 1.5x sensor, f/10 produces the sharpest and most detailed image, and higher f-ratios take a hit due to diffraction softening. Then you will get 10 MP worth of detail at f/15 on a FF sensor, regardless of how many pixels it has (as long as it's at least 10 MP). However, if we instead use f/10 on the FF sensor, then if it had the same pixel density as the 1.5x sensor, you could get 22.5 MP worth of detail.

samjNC said:
Also, with my D50, if I want lots of DOF, could I go to f16 and be
OK? How much worse is f/11 v. f/16 or f/22 or f/32 for the D50?

You can use the diffraction calculator here:

http://www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm

For a 6.1 MP 1.5x DSLR, f/12.8 is your diffraction "limit" -- the highest f-ratio that you can use before suffering from diffraction softening. I think that calculator is a bit off, however. If you go to http://www.slrgear.com and look at various lenses tested on a Nikon D200, you'll see that they seem to peak between f/5.6 and f/8 -- we'll say f/6.3 as it seems closer to f/5.6 than f/8.

Anyway, the D200 pixels are 1.29 times the dimensions as the D50 pixels, so a D50 should peak around f/8. This means that a D3 would give you 6 MP worth of detail at f/12 or could give you 13.5 MP of detail at f/8 if it had that many pixels.

Of course, this all presumes that the parts of the scene you want within the DOF are within the DOF. Sometimes it's a lot smarter to stop down, despite diffraction softening, to get more of your image within the DOF, as that will give you more detail overall , but will be slightly less sharp (depending on how much you stop down) for the elements in the frame very close to the focal plane.

Anyway, I hope this all makes sense!

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

joe mama · Mar 31, 2008

DUSTY LENS said:
Diffraction is caused by light rays that in some way are effected be
reflecting off of the edge of the aperture blades and then landing on
the sensor in the wrong place .

No, not even close. Here ya go:

http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

DUSTY LENS said:
This is reduced in larger formats and sensors because lenses must be
longer in focal length to get the same perspective with larger
formats and larger sensors .

Again, not even close. Perspective is a function only of subject-camera distance, framing is a function of FL and perspective, and neither have anything to do with diffraction.

DUSTY LENS said:
This is because a longer lens focal length will need a larger area
inside the aperture opening to deliver the same f ratio . ( lens
opening for the same amount of light to pass through ) .

Now you're talkin'! : )

DUSTY LENS said:
This effects the percentage of light which passes...

Yes.

DUSTY LENS said:
without grazing the aperture blades compared to the amount of light which
passes through but suffers the effects of diffraction by striking the edge of
the aperture.

No.

DUSTY LENS said:
The smaller aperture , ( which is in the shorter focal length lenses
used for smallerer sensors ) has more light effected by diffraction)...

That doesn't even make sense. Anyway, read the link above -- it explains it.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

DUSTY LENS · Apr 1, 2008

Joe ,

I took a quick look at the site you posted and just as quickly found some wrong statements and assumings .

From the web site you posted ( http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm ) .

“Ordinarily light travels in straight lines through uniform air, however it begins to disperse or "diffract" when squeezed through a small hole (such as your camera's aperture). “

Wrong light does not squeeze through a small hole anymore than moths have balls .

And light travels in nearly straight lines except when refracting , reflecting , traveling through a strong gravitation field , like a black hole , or when traveling through a material having a gradation of density . The Author is confusing diffraction with interference patterns this is caused when light falling on a surface from the same source but through two different pathes , this light is made to converge on a surface and in some places on that surface , the two different path light rays happen to fall in phase doubling the energy , while at other places the two happen to fall exactly out of phase , canceling the energy .

The small hole will always have a higher amount of light reflecting off it’s edges for a given amount of light passing through than a large hole . It is the contact or partial contact with the edge of the aperture blades which deflects the travel of the light .

Next statement :

“ at some aperture the softening effects of diffraction offset any gain in sharpness due to better depth of field .”

This is not very accurate , diffraction does not really eliminate depth of field , it limit’s the sharpness mostly where there would have been high sharpness , ( at the accurately focused distance .

Depth of field is still available with lesser change in already out of focus distances .

Another one ,

For an ideal circular aperture, the 2-D diffraction pattern is called an "airy disk," after its discoverer George Airy. The width of the airy disk is used to define the theoretical maximum resolution for an optical system (defined as the diameter of the first dark circle).

Here the word diffraction is talking about dark rings which are caused by out of phase light canceling the energy at the image surface . ( Not diffraction )

The light deflected from one side of the aperture edge falls where light is also falling having been deflected from the other side of the same aperture hole . Interference not diffraction . Remember every aperture has an edge all the way around it so light can reflect from opposite sides and still land in the same place and this place can form a circle or more than one circle .

So if someone wants to call interference patterns " diffraction " OK , but this doesn’t prove it is not interference caused by reflections and out of phase energy misnamed for lack of understanding .

I was explaining something in a language everybody could use , not trying to impress anyone that I know everything , even if I do .

sherwoodpete · Apr 1, 2008

DUSTY LENS said:
I was explaining something in a language everybody could use , not
trying to impress anyone that I know everything , even if I do .

Well, you've repeated some of your previous incorrect statements here. For example the idea that light is reflected from the edge of the aperture blades as the explanation for diffraction. That's not just an over-simplification, it's actually wrong. Light reflected from the aperture blades can give rise to star-shaped halos around bright light sources in a photograph. But that is not diffraction.
Regards,
Peter

Deejaybee · Apr 1, 2008

DUSTY LENS said:
So if someone wants to call interference patterns " diffraction " OK , but this > doesn’t prove it is not interference caused by reflections and out of phase > energy misnamed for lack of understanding .

Sadly, it does disprove your 'theory', see Peter's answer above. Diffractions patterns are described very accurately by the effects of truncating a wavefront- which result in interference. I suggest your direct your reading towards Huygens principle, and Fraunhofer diffraction on whatever medium works for you best.

DUSTY LENS said:
I was explaining something in a language everybody could use , not trying to > impress anyone that I know everything , even if I do .

Indeed. Well at the risk of appearing brusque, assuming you are optically all-knowing it should not be an issue to run the calculations for yourself: I would suggest the following:

Calculate the path mismatch for, say a 50mm lens at F11 for the sake of argument. Assume a 5000K black-body source spectrum convolved with a 100nm filter width from which to calculate your coherence length. Is the path difference of your reflected light within the coherence length of the source? Note that you will have to assume a subject distance. Also note that diffractive spreading (see above) is not distance dependant.

Simiilarly you should easily be able to calculate the amplitude of light that is reflected off of the aperture blades given the incidence angle of the incoming light which can strike them. Make them 50um in thickness for the sake of argument and assume a reasonable profile of your chosing and the same F11. How does the amplitude of the reflected light which can be collected at the same spot as the primary signal, and within the coherence length of the primary signal, compare to the intensity coming through the open aperture?

Re-assess your assertion that driffraction is caused by reflections of a given apertures edges.

regards

--
DeeJayBee

deejaybee.smugmug.com

joe mama · Apr 1, 2008

DUSTY LENS said:
I took a quick look at the site you posted and just as quickly found
some wrong statements and assumings .

From the web site you posted (
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm ) .

“Ordinarily light travels in straight lines through uniform air,
however it begins to disperse or "diffract" when squeezed through a
small hole (such as your camera's aperture). E>
Wrong light does not squeeze through a small hole anymore than moths
have balls .

This is an oversimplification of the wave-particle duality of light. The author is treating light as a particle with the above statement, whereas diffraction is an effect of the wave nature of light. Eh -- no one's perfect. Well, I know of one exception. : )

DUSTY LENS said:
And light travels in nearly straight lines except when refracting ,
reflecting , traveling through a strong gravitation field , like a
black hole , or when traveling through a material having a gradation
of density . The Author is confusing diffraction with interference
patterns this is caused when light falling on a surface from the
same source but through two different pathes , this light is made to
converge on a surface and in some places on that surface , the two
different path light rays happen to fall in phase doubling the energy
, while at other places the two happen to fall exactly out of phase ,
canceling the energy .

Yeah, that's basically correct, but it's far from what you said about "bouncing off of aperture blades".

DUSTY LENS said:
The small hole will always have a higher amount of light reflecting
off it’s edges for a given amount of light passing through than a
large hole . It is the contact or partial contact with the edge of
the aperture blades which deflects the travel of the light .

See what I mean? What you said above is completely, and totally, false.

DUSTY LENS said:
Next statement :
Eat some aperture the softening effects of diffraction offset any
gain in sharpness due to better depth of field .E>
This is not very accurate , diffraction does not really eliminate
depth of field , it limit’s the sharpness mostly where there would
have been high sharpness , ( at the accurately focused distance .

You misunderstand. The greater the DOF, the more of the image that will be sharp, but the more the image will suffer from diffraction softening. There's a give and take between diffraction and DOF for maximal image sharpness across the frame.

DUSTY LENS said:
Depth of field is still available with lesser change in already out
of focus distances .

I have no idea what that means.

DUSTY LENS said:
Another one ,
For an ideal circular aperture, the 2-D diffraction pattern is called
an "airy disk," after its discoverer George Airy. The width of the
airy disk is used to define the theoretical maximum resolution for an
optical system (defined as the diameter of the first dark circle).

Here the word diffraction is talking about dark rings which are
caused by out of phase light canceling the energy at the image
surface . ( Not diffraction )

You might want to look up the word "diffraction" -- that is the very definition of it is based on constructive and destructive interference.

DUSTY LENS said:
The light deflected from one side of the aperture edge falls where
light is also falling having been deflected from the other side of
the same aperture hole . Interference not diffraction.

See what I mean? Here, I'll cite you a link:

http://en.wikipedia.org/wiki/Diffraction

Read "The mechanism of diffraction".

DUSTY LENS said:
Remember every aperture has an edge all the way around it so light can
reflect from opposite sides and still land in the same place and this
place can form a circle or more than one circle .

Again, totally incorrect.

DUSTY LENS said:
So if someone wants to call interference patterns " diffraction " OK

It's not "someone" -- it's the entire planet that understands the principle.

DUSTY LENS said:
, but this doesn’t prove it is not interference caused by reflections
and out of phase energy misnamed for lack of understanding .

Seriously, you should have looked up "diffraction" before making this, and your previous, post.

DUSTY LENS said:
I was explaining something in a language everybody could use , not
trying to impress anyone that I know everything , even if I do .

I can explain the Easter Bunny and the Tooth Fairy in a "language everybody could use" but that wouldn't make them real. And I don't know where you get off implying I'm "trying to impress anyone that I know everything" when all I'm doing is correcting your massive misunderstanding.

You know, when people tell me I'm wrong, I often rework my calculations and consult outside sources to see if I missed something, and then correct myself if I find myself to be in error. You might try the same rather than lashing out at those who are correcting you.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

Amypics · Apr 1, 2008

DUSTY LENS said:
samjNC ,

Diffraction is caused by light rays that in some way are effected be
reflecting off of the edge of the aperture blades and then landing on
the sensor in the wrong place .

Errr... NO. If that was the case, it would be called reflection and not diffraction.

read http://en.wikipedia.org/wiki/Diffraction
and then http://en.wikipedia.org/wiki/Diffraction-limited

Amy

Jim Michael · Apr 3, 2008

If you have a laser pointer handy, shine it on the edge of a razor blade a few inches away from a white card. You should see a diffraction pattern behind the blade. A few years ago I made pinholes for cameras and used the diffraction pattern to judge the size of the holes using a formula for distance of the minima and maxima of the pattern.

DUSTY LENS · Apr 4, 2008

joe mama ,

I did exactly as you suggested , I looked at the website you posted again , and this is the first thing I saw there :

" The complex patterns resulting from the intensity of a diffracted wave are a result of interference between different parts of a wave that traveled to the observer by different paths. "

This is exactly what I said in the beginning joe mama .

What is so bind numbing about admitting that I am right , and I know it .

Also I said some kind of reflecting and grazing of the aperture blades , Meaning that the diffracting process is not completely known by myself .

So I was not pretending to know everything as accused , I said even if I do know everything I would not try to impress everyone with that .

You and a few others here seem to have some special interest in this ego thing to the degree that you need to attack and discredit what others say , even when they are right .

I stand on what I have said here , and it is nit picking finaticism or obsession to go beyond this .

joe mama · Apr 4, 2008

DUSTY LENS said:
I did exactly as you suggested , I looked at the website you posted
again , and this is the first thing I saw there :

" The complex patterns resulting from the intensity of a diffracted
wave are a result of interference between different parts of a wave
that traveled to the observer by different paths. "

The above is correct.

DUSTY LENS said:
This is exactly what I said in the beginning joe mama .

No, it is not. Allow me to quote what you said:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=27383600

DUSTY LENS said:
Diffraction is caused by light rays that in some way are effected be
reflecting off of the edge of the aperture blades and then landing on
the sensor in the wrong place.

Wrong. I don't know how many times I have to tell you that, and how many other people have to tell you that, until you realize it, understand it, and stop calling us who are correcting your error "arrogant".

You then go on to say:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=27398158

DUSTY LENS said:
Here the word diffraction is talking about dark rings which are caused
by out of phase light canceling the energy at the image surface. (Not
diffraction)
The light deflected from one side of the aperture edge falls where
light is also falling having been deflected from the other side of
the same aperture hole . Interference not diffraction.

Yes -- "diffraction". I even cited you a link to explain that point to you:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=27402660

"See what I mean? Here, I'll cite you a link:

http://en.wikipedia.org/wiki/Diffraction

Read 'The mechanism of diffraction'. "

DUSTY LENS said:
What is so bind numbing about admitting that I am right , and I know
it .

What's so mind numbing is that you say:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=27436086

DUSTY LENS said:
Also I said some kind of reflecting and grazing of the aperture blades,
Meaning that the diffracting process is not completely known by myself .

admitting that you do not understand diffraction, yet, in the same breath, say that you are right and that you know it. Sheesh!

See what I mean?

DUSTY LENS said:
Also I said some kind of reflecting and grazing of the aperture
blades , Meaning that the diffracting process is not completely known
by myself .

Exactly. As you say, "...the diffracting process is not completely known by myself." So where do you get off telling those of us who do know, and who are correcting you, that we are arrogant?

DUSTY LENS said:
So I was not pretending to know everything as accused , I said even
if I do know everything I would not try to impress everyone with that.

Who's trying to impress anyone? We're just correcting your admitted errors because we do know what diffraction is.

DUSTY LENS said:
You and a few others here seem to have some special interest in this
ego thing to the degree that you need to attack and discredit what
others say , even when they are right .

You are WRONG ! What is the deal with you?! You admit to not knowing, yet you somehow feel that those of us correcting your ignorance are arrogant. No sir, it is you who is arrogant by refusing to educate yourself on the subject.

DUSTY LENS said:
I stand on what I have said here , and it is nit picking finaticism
or obsession to go beyond this .

Dude, I could care less what you stand by. You are wrong, and you have no interest in understanding why. That's a real shame. I mean, there's no shame in ignorance, but there is shame in not wanting to educate yourself.

Just because you do not understand diffraction, does not mean that no one else does. There have been several people in this thread telling you that you are wrong, and you refuse to listen. Good luck with that.

Later dude.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

DUSTY LENS · Apr 5, 2008

joe mama ,

I just proved to you that what I said in the beginning was correct , that diffraction is caused by the light which is effected , ( reflected , broken , caused to change direction , by the close encounter with the aperture blade , or by a near close encounter with the aperture blade ) . and ( I fully admit , I don't know which of these or how many of these are involved in diffraction ) But I do know this :

From the website you posted as an authority :

http://en.wikipedia.org/wiki/Diffraction

The complex patterns resulting from the intensity of a diffracted wave are a result of interference between different parts of a wave that traveled to the observer by different paths.

The patterns are not diffraction the patterns are evidence of ,and are caused by ,

interference . meaning light which traveled from the same source through different paths and landed at the same place on an image forming surface and which landed with some of the light falling out off phase to differing degrees and therefore canceling the energy of out of phase waves .

That is not diffraction it is interference . Why don't you just admit that I was right from the beginning , and drop your unreasonable arguments .

You probably have no knowlege as to the physical cause of diffraction ( reflection , damaged photons , attraction to metal , or just being too close to a rough edge ,
So you really do not know what you are talking about anyway .

If you did you surely would have let everyone know by now , but you have not .

This is my final attempt to make you honest .

Leon Wittwer · Apr 5, 2008

DUSTY LENS said:
That is not diffraction it is interference . Why don't you just admit
that I was right from the beginning , and drop your unreasonable
arguments .

Diffraction and interference are not mutually exclusive. Virtually all of the wave nature of light can be described as the result of coherent interference between light traveling different paths including diffraction. Diffraction can be described as interference caused by having sharp boundaries limiting a waves spatial extent. This can be a slit or an aperture as in optics.

By the way, I am a retired PhD scientist and engineer and still remember my business.
--
Leon
http://homepage.mac.com/leonwittwer/landscapes.htm

joe mama · Apr 5, 2008

DUSTY LENS said:
You probably have no knowlege as to the physical cause of diffraction
( reflection , damaged photons , attraction to metal , or just being
too close to a rough edge ,

I think you're just weird. Everything you wrote above is pure gibberish. Please, link me to a site that talks about "damaged photons", or the connection between "attraction to metal" and diffraction, etc. I mean, seriously, what the hell are you talking about?

DUSTY LENS said:
So you really do not know what you are talking about anyway .

In fact, I do. But you're some sort of self-absorbed quack. Got that perpetual motion machine up and running yet?

DUSTY LENS said:
If you did you surely would have let everyone know by now , but you
have not .

If I let everyone know what? That I know about diffraction? How many times did I link it to you. What did the scientist/engineer tell you just above this post?

DUSTY LENS said:
This is my final attempt to make you honest .

Please, just walk away. It's painful to see your supreme arrogance as you make no attempt to educate yourself despite what I, and several others, in this thread have tried to do for you.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

sherwoodpete · Apr 5, 2008

We've probably all heard the phrase " a picture paints a thousand words". So I will try to keep the words here to a minimum.

Above is a photograph of waves (coming from bottom right) in a water tank, in which is a barrier with a single gap. The waves emerge from the gap as if the gap itself was the source of the new waves on the other side.

This is consistent with the Huygens–Fresnel principle. See below waves passing through a gap several wavelengths wide:

Reference: http://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle

Regards,
Peter

mike703 · Apr 5, 2008

DUSTY LENS said:
You probably have no knowlege as to the physical cause of diffraction
( reflection , damaged photons , attraction to metal , or just being
too close to a rough edge ,
So you really do not know what you are talking about anyway .

This is complete and utter gibberish in every respect. Please, stop arguing and go and read about diffraction on wikipedia or in a physics text book.

--
Mike

nokem · Apr 5, 2008

--
Shoot.

DUSTY LENS · Apr 6, 2008

Reply to Peter ,

DUSTY LENS said:
I was explaining something in a language everybody could use , not
trying to impress anyone that I know everything , even if I do .

Well, you've repeated some of your previous incorrect statements here. For example the idea that light is reflected from the edge of the aperture blades as the explanation for diffraction. That's not just an over-simplification, it's actually wrong. Light reflected from the aperture blades can give rise to star-shaped halos around bright light sources in a photograph. But that is not diffraction.
Regards,
Peter

I'm sorry Peter , but I know about the star shaped light streaks around bright spots in photographs too , and these star shaped patterns of bright streaks are also proof of what I have said before . I will explain here , ( though I doubt that you will understand or admit that you understand ) .

Aperture blades in most lenses are not sufficiently rounded at every exposed portion to the opening , to reflect evenly from all points along the exposed part of the blades . Where the length of the exposed blade is less curved or is straightest , the light is reflected in a concentrated direction causing the streak you see as a star point .

This is an example of diffraction which is concentrated in one direction , ( the star point streak of brightness in the photograph .

So , this is very strong evidence of reflection being a predominant form , or contributor to what we call diffraction . any reasonable person who has a brain educated or not can agree to this .

We are talking about the image degrading effects of the aperture when the opening is made very small and a high percentage of the light passing through is effected by the edge of that opening or by the aperture blades .

We are not talking about who is a scientist or who is a PHD or who is educated , etc. etc. etc. .

There is always more degradation in the image caused by the same reflection which is not concentrated enough to form a streak but is contributing to image blur degradation also .

Some lenses have more rounded aperture blades which do not cause these bright streaks we call star points and this is further evidence of what I have always said .

I am not a scientist by any diploma or sheepskin degree , but I am also not stupid like some people in this argument seem to be .

Sorry if the truth hurts , it is still the truth .

joe mama · Apr 6, 2008

DUSTY LENS said:
I am not a scientist by and diploma or sheepskin degree

No kidding.

DUSTY LENS said:
but I am also not stupid like some people in this argument seem to be .

No, you aren't -- you're far worse.

DUSTY LENS said:
Sorry if the truth hurts, it is still the truth.

The truth may or may not hurt, depending on the circumstance, but in this case, you'll never know, unfortunately.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

diffraction

Leading Member

Senior Member

Forum Pro

Forum Pro

Senior Member

Veteran Member

Forum Enthusiast

Forum Pro

Senior Member

Member

Senior Member

Forum Pro

Senior Member

Forum Pro

Forum Pro

Veteran Member

Veteran Member

Leading Member

Senior Member

Forum Pro

Keyboard shortcuts