UV Filter suggestions?

[Ben-71]

<< Yeah I'm speaking generally here. In nearly all situations you would not need them, but I have had a few shots of film go blue when photographing snow before because of the high UV exposure. >>
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This is becoming boring, as I agree with you again...
UV blocking is also importatnt to wedding phot', as some of the cloths of those white dresses emit so much UV that they turn bluish in the photographs.

<< ... any anti-IR filter you put on your camera that isn't specifically customised exactly for the sensor is likely to have either no effect at all, or may turn the image bluish. Letting through some of the IR spectra to the sensor (D70 does this) may help the sensor produce a normal image. >>
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With a D300, I saw no difference w/ or w/o IR blocking.

<< .... I saw one saying that the Thinner glass makes it more suited for digital cameras. I mean what the... ​

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The "more suited for digital cameras" is indeed ridiculous, but the principle is true.
The wider the angle of view, the more glass light passes when it comes from the side, vs light from the front.
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This means trouble at the edges.
So, thinner filter glass is better, but for film as well.

We'll probably agree on that too

 

[Ben-71]

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[Socrates]

Yeah I'm speaking generally here. In nearly all situations you would not need them, but I have had a few shots of film go blue when photographing snow before because of the high UV exposure.

What I was saying with IR is that yes it's sensitive, and yes it lets some through, but the imperfection of filter design means that any anti-IR filter you put on your camera that isn't specifically customised exactly for the sensor is likely to have either no effect at all, or may turn the image bluish. Letting through some of the IR spectra to the sensor (D70 does this) may help the sensor produce a normal image.

Either way it's not a worthy investment and in any case more often than not the Designed for Digital is marketing fluff. Look at the descriptions on the box. I saw one saying that the Thinner glass makes it more suited for digital cameras. I mean what the...

Actually, sensors ARE sensitive to IR and UV light but all digital cameras are built with non-removable filters in front of the sensors. These permanent filters block all light that's not normally visible to the human eye which, of course, includes IR and UV. Film cameras did not have those filters in front of the film. Consequently, unlike film cameras, digital cameras have no need for a UV filter. Some individuals use it for lens protection but, in that case, a clear glass "protector" filter is a better choice.

I'm unable to address your comment regarding the D70. Where did you get that information?

 

[Ben-71]

Actually, sensors ARE sensitive to IR and UV light but all digital cameras are built with non-removable filters in front of the sensors. These permanent filters block all light that's not normally visible to the human eye which, of course, includes IR and UV. .... Consequently, unlike film cameras, digital cameras have no need for a UV filter. Some individuals use it for lens protection but, in that case, a clear glass "protector" filter is a better choice.

Try it...:
Darken a room, light up a UV bulb ("black light" bulb), and take a shot of it.
There's that built-in filter, even the glass in the lens blocks some UV,
but the camera will capture a picture.

The same is true for the other side of the visible spectrum:
Darken a room, hold a TV remote control in front of the lens, press a button so it transmits, and take a shot.
You'll get a picture of the NIR (near infra red) source.

Unlike film cameras, digital cameras are IR cameras.
With an IR filter - which transmits only NIR - digital cameras can capture interesting photographs.

The IR/UV blocking layer on the sensor is not made to block just enough, so that, in most normal conditions, the pic' is not influenced. 'Most', but not 'all'.
e.g.:
Try taking shots (w/o flash) at a club, where the light is dim, and there're UV lamps. Some synthetic cloths will glare with UV.
Put on a good UV blocking filter, and the glare, and hue changes, are gone.

Cameras are somewhat different from each other in the amount of UV or IR internal blocking.

About a month ago, we had one of those very hot days, accompanied with fine-soil dust storm (thin yellowish dust, carried by wind, along hundreds of miles from the Sahara).
Visibility was much reduced.
Out of curiousity, I picked up the D300 and took a pic' of an antenna pole, about 0.5 mile away.
The pole was hardly visible, in the pic' as well.
Then, I took it again, through an IR filter (passes near IR only).
Not only the pole was much sharper, but the thin wires that hold it, and which weren't visible at all, were visible in the pic'.

Digital cameras offer "more than meets the eye"...

 

[Alex_B]

B+W here.

 

[Ben-71]

Ooops...

Not -

<< The IR/UV blocking layer on the sensor not made to block just enough, so that, in most normal conditions, the pic' is not influenced. 'Most', but not 'all'.
e.g.: >>

But -

The IR/UV blocking layer on the sensor is made to block just enough, so that, in most normal conditions, the pic' is not influenced. 'Most', but not 'all'.

Sorry.

 

[Socrates]

Try it...:
Darken a room, light up a UV bulb ("black light" bulb), and take a shot of it.
There's that built-in filter, even the glass in the lens blocks some UV,
but the camera will capture a picture.

You don't honestly believe that an inexpensive "black light" bulb produces pure UV illumination and nothing else, do you?

The same is true for the other side of the visible spectrum:
Darken a room, hold a TV remote control in front of the lens, press a button so it transmits, and take a shot.
You'll get a picture of the NIR (near infra red) source.

Do you mean the same visible red light that I can see?

Unlike film cameras, digital cameras are IR cameras.
With an IR filter - which transmits only NIR - digital cameras can capture interesting photographs.

The IR/UV blocking layer on the sensor is not made to block just enough, so that, in most normal conditions, the pic' is not influenced. 'Most', but not 'all'.

This is a C&P from the Nikon knowledge database:
"Nikon designers go to great lengths to remove as much of the infra-red light as is necessary to produce the closest image to what we can see with the human eye."

 

[Garbz]

I'm unable to address your comment regarding the D70. Where did you get that information?

While researching my IR stuff for my D200 I stumbled across a website with test results for various cameras using Hoya R72 and RM90 filters. Test shots were taken and EVs of the correct exposure were calcualted. The D200 gave an EV of -1.3, the Canon 450D somewhere up near 6 along with the D40, the D70 and D100 both gave figures of around 7.8 which is why it's much easier to get an IR effect on those cameras.

You took my comment out of context. Of course CCDs are IR sensitive. In fact some of my colleges in my thesis lab use CCDs to determine the irradiation pattern of lasers. I was just saying just because a filter is sensitive to IR doesn't make it a bad sensor, and therefore I am not sure that the camera will perform better (possibly it will be worse) if you further block more of the IR spectra with a filter not customised to the sensor like many of the ones in current cameras.

 

[prodigy2k7]

black light isnt pure uv light. some visible light gets out anyway

 

[Ben-71]

Dear Socrates,

<< You don't honestly believe that an inexpensive "black light" bulb produces pure UV illumination and nothing else, do you? >>

Try this, with an inexpensive one UV bulb… :
Put it in a closed shoe box. Seal it with black duct tape.
Make a hole, and cover it with a good, expensive UV-only filter, to cut off the visible range. You'll still get a pic' of the light source.

<< Do you mean the same visible red light that I can see [getting out from a remote control] ?

If you tried it in complete darkness and saw some red light, it came from the red LED on top. Cover it… One doesn't see IR.
Even if you don't cover the LED, and just point the RC a bit upwards, the body of the RC blocks it from directly reaching the lens.
This way, the LED cannot create a clear & bright image of a circular light source, because the lens doesn't 'see' the LED, certainly not in 1/10 sec. or so, which was the auto exposure when I tried it.

In complete darkness, we may see noise in our eye-brain system, but not IR.
Even if you think that you saw a very faint something, it couldn't be enough for the camera to capture an overexposed white area in the middle of the pic', in 1/10sec.

<< This is a C&P from the Nikon knowledge database:
"Nikon designers go to great lengths to remove as much of the infra-red light as is necessary to produce the closest image to what we can see with the human eye." >>

Earlier, you said –
<< These permanent filters block all light that's not normally visible to the human eye which, of course, includes IR and UV. >>

At Nikon, which you quote, they're careful NOT to say that.

They say -
"….to remove as much of the infra-red light as is necessary to produce the closest image to what we can see with the human eye."

Nikon do not claim blocking "all" IR or UV, they do not claim to exactly match what the eye sees, and they're right.

What I said, in 'less promotional' words, is basically the same:
"The IR/UV blocking layer on the sensor is made to block just enough, so that, in most normal conditions, the pic' is not influenced".

There're quite a few IR photographs on the Internet, most are IR plus a bit of visible red, some are pure IR.
Even in those that include some visible red, how can the typical wild color shift of IR photography be explained, if the camera can record only the visible red ?

It is simple to try with a remote control – please do.
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