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UltravioletPhotography

Ebay Converter: Neimartphoto (neimartphoto)


Andrea B.

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We have had NO reports about this Ebay converter. I note that neimartphoto's ads do rebut some of the scare tactics seen in eeassa's ads (discussed in another post here). But then neimartphoto adds a bit of his own hysteria about Spectrosil.

 

The bolding is mine and may differ from the ad.

 

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http://www.ebay.com/...LEAAOSwgyxWXRXa

 

Why to buy from us?

  1. We use highest quality MADE IN USA products for our conversion services.
  2. We use Double Side Multi Layer Anti Reflective coated borofloat glass with transmission range from 280nm till 2,500nm. Please note, that NO camera sensor can see shorter that 280nm and longer that 1150nm. This glass we use does NOT limit sensor's properties.
  3. Yes we know there are other conversion service providers. But unlike them we respect you and we do not try to mislead you with brands and trade marks that mean NOTHING in respect to the camera you send for conversion.

Why it makes NO sense to use ANY uncoated quartz (Spectrasil, Infrasil, Suprasil , etc) windows for Full Spectrum conversion?

 

There are sellers who offer you to place uncoated Quartz windows instead of IR Cut filter.

You might read about Spectrasil, Infrasil, Suprasil and other "VERY COOL SIL" quartz windows.

The truth is that they are not just useless from camera point of view but they are inferior to

ANY Anti Reflective Coated borofloat window. Here is why:

  1. Uncoated quartz (does NOT matter what kind and what brand) has about 90% transmission in the region your camera sensor can see. What does it mean? those 10% of light did not pass through SUPERxxx window got reflected back to the lens and will reduce contrast and clarity of your photos. You will get more reflections!
  2. Claims that Spectrasil window transmits from 190nm UV has NOTHING to do with you camera. They are IRRELEVANT. Here is why.

  • Your camera will never be subjected to 190nm UV.
    UV light in the region up to about 250nm is being called Vaccum UV.
    You know why/. Because it does not propagate through the air. Yes, air absorbs it.
    Your camera will never see 190nm UV in its life unless you are going to fly to International Space Station
    and will not go to open space with your camera. Then yes, it will be subjected to UV light of 190nm.
    But wait, even if you send your camera to open space still it will not be able to take photos in 190nm.
    Why? Do you have a lens made of Spectrasil? No?..
  • NO camera sensor is sensitive to UV lower than 280m! NONE! Period.
    EVERY camera sensor comes ENCLOSED air tight sealed in glass top envelope.
    YES GLASS TOP. NOT QUARTZ top! GLASS.
  • No matter of what Samsung NX camera sensors do not see UV at all!
    Glass envelop they are encapsulated in FULLY absorb ANYTHING below 380nm!
    Only one brand cameras can see down to 280nm. Most sensors are sensitive from 320nm and up!

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So, whew!

 

I agree that our cameras will most likely never be "subjected to" 190nm UV light, but, hey, I'm not ruling out a trip to the Space Station.

 

Spectrosil causes more reflections? I do not know from my own experience. We haven't had any reports of this so far.

Does anyone have any information about this?

 

Valid point about glass sealed sensor. Although to be fair, sometimes a non-glass sealant is used.

 

Only one brand cameras can see down to 280nm.

TELL US WHAT IT IS!! PLEASE!! And how you know this. Because we do not know this here at UVP. :D

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Borofloat passes less UV than quartz. This seller seems to be turning that into a positive, but since I would like my camera to record as much UV as possible, especially near the 300nm end, I am not a fan.

 

So far I have noticed no reflections from the spectrosil, but it's early days still.

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since I would like my camera to record as much UV as possible, especially near the 300nm end

 

Did you have something specific in mind to shoot in this 300nm range?

The key factor is having enough illumination in that range. I'm not sure what that would be.

 

And the glass portions of the sensor still prevent much under 300nm from being recorded.

Maybe you could get to 280nm in studio conditions with special lighting and narrow bandpass filters?

 

Please remember that startng around 300nm you would begin to get into the DNA damaging version of UV light.

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Andrea, getting artificial UV sources near the 300nm end doesn't seem to be a problem. There's quite a bit of equipment for viewing fluorescent minerals and so on available. If I ever actually get around playing with this (I.e. not soon) then I would probably build an enclosure to shield the light source and try to make the setup in such a way that skin and UV never have to meet. There would definitely need to be special bandpass filters involved. Also I was thinking something like a zone plate instead of a lens. And very long exposures.
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Andy, yes, laboratory conditions. Good!!

I wonder if one of the Reptile lamps would be useful?

 

 

Gonna snag the chart from the Wicked article about Sunlight.

Sunlight is not a good provider of 300nm unfortunately.

See also: It's Rough Down There at 293 nm.

 

 

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Spectrum of the visible wavelengths at approximately sea level; illumination by direct sunlight compared with direct sunlight scattered by cloud cover and with indirect sunlight by varying degrees of cloud cover. The yellow line shows the spectrum of direct illumination under optimal conditions. The other illumination conditions are scaled to show their relation to direct illumination. The units of spectral power are simply raw sensor values (with a linear response at specific wavelengths).

800px-Spectrum_of_Sunlight_en.svg copy.jpg

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At the rate we are going, perhaps not for long!

 

But anyway, I'm eager to see some work around 300nm. Go for it!

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Seller is correct in one thing - sensor cover is made from glass, and its transmission properties are close to N-BK7. I've seen the transmission graph.
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Yes, I try to look up these Ebay ads periodically to see what is being offered and how misleading or snarky the ads are getting.

 

I had forgotten that you dug out that Niemartphoto seemed to be associated with Image Laboratory.

 

These days it seems like every guy with a screwdriver has an Ebay conversion store. :D

 

There are actually a few others I have not reported on who seem to have a "quieter" approach to selling camera conversions without scare tactics or bragging or dissing other sellers or misinformation.

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