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88Teo88

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Hello everyone:)

 

I'm a software developer, but nowadays an antique dealer/collector, I have a little antique shop, and I take photos of items every day, but the paintings were always problematic, to figure out who the painter is. Therefore I would like to learn about IR photography, reflectography and build a system to analyze them.

 

 

 

Thank you: Teo from Hungary

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Hi Teo! Here you can find loads of information about UV/IR photography, but I will try to tell you the essential for IR:

 

You don't really need a converted camera, but it depends on your camera (some will work better than others, depending on the UV/IR cut filter on the sensor) but a full-spectrum or IR-converted one will work much better;

 

Typical IR light sources are tungsten lamps and LEDs, they both work well, if you need a broad spectrum you should use a tungsten-based one (like a halogen lamp);

 

Most lenses transmit IR well, but some will have an IR hotspot;

 

There are a lot of longpass filters for IR photography, such as Hoya R72 or Schott RG850. Your camera will be able to see up to 1100 nm, not more, if you want to explore SWIR you need a SWIR camera (Andy has a TriWave for example), but they are difficult to find and often very expensive.

 

Hope to see more from you.

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Looking forwards to seeing your work & experiments too.

I think UVA will be useful too with reflected UVA & UVA induced visible light fluorescence ( UVIVF ).

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Thank you so much for your kind replies:)) it looks a really good community

I was reading a lot about it in recent months, and I would like to write a longer post in the next days

Thank you again It is nice to be here:)

Teo

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Yes please post images. I need some inspiration.

Seems like 100 new sign upers in last 6 months and only the older users (on for more than a year) are posting.

 

I also need to post more cool stuff. Now that scary UV is in my hands. I will have to take some images.

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  • 3 weeks later...

I was tried to read everything about this theme, how to convert a camera, filters, lamps, colours, but I still have many questions:)

How to convert a dslr camera to a full spectrum camera: to remove that hot mirror filter, but then the focus will be bad, if I don't replace it with a glass plate:

http://www.astrosurf.com/luxorion/photo-ir-uv.htm but where can I buy a glass plate of this size?

I have an older Nikon D3300 with a Nikon 18-105/F3.5-5.6 for this, but I'm ready to buy anything what would be better:) they used a Nikon D800 with these lenses:

https://chsopensource.org/infrared-photography-lenses-database/ in this project: https://chsopensource.org/infrared-photography-ir/

but I don't think that would be a bigger difference, or this one?: https://kolarivision.com/product/fujifilm-x-t1-infrared-converted-camera-body/

and I read everywhere that a digital camera can record light until about 1100nm, but I found this camera on ebay:

https://www.ebay.com/itm/Full-Spectrum-Converted-Canon-EOS-7D-Mark-I-DSLR-Camera-UFO-Ghost-UV-IR-Astro/183198817778?hash=item2aa7801df2:g:HmgAAOSwihVb7qz-

 

and it says that, the wavelength ranges is from 300 to 3000nm, then is it fake ranges? (because it would be fantastic to me, but I always read that I need a SWIR camera:))

 

I checked the filters too, and I think the Hoya R72 would be really good, but what do you think about the Hoya RM90 and RM100 and schott rg1000?

http://uvlp.com/hoya-filters/infrared-transmitting-filters/

 

Lamps: halogen, leds

https://chsopensource.org/infrared-photography-ir/

I found this led light:

https://www.amazon.com/gp/product/B07NKT8VC7/ref=ox_sc_act_title_1?smid=A2U3HRVGBEQ59&psc=1

but they said that Its maximum wavelength is 950nm only

which halogen lamp would be good?

and maybe It is totally wrong but I asked about the infrared lamps too, for example:

https://www.amazon.co.uk/Beurer-IL11-Compact-Infrared-Lamp/dp/B000KKEFVK

and they said it is between 800nm and 1500nm

or this one:

https://www.amazon.com/Beurer-Infrared-Increases-Circulation-IL50/dp/B00IVPMZKE/ref=sr_1_1_sspa?dchild=1&keywords=Beurer+IL50&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUjYxVzQxTDcyM0wwJmVuY3J5cHRlZElkPUEwMzM0NTE3MVpBVjBMS0xWRU5UNCZlbmNyeXB0ZWRBZElkPUEwNzkzMDYzMlA2QTE5SUpEUk5FViZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

from 500nm to 2500nm

 

other filters, in front of the lights:

black and white film: 1240-1350nm

Kodak High speed infrared film: 700-900nm

 

somewhere I read that there is an alternative filter: old floppy disk also would be good for infrared, but I don't know what wavelength this is:)

 

any help would be fantastic to me:) and I'm sorry for my poor english:)

Thank you so much: Teo

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[...]but I found this camera on ebay:

https://www.ebay.com/itm/Full-Spectrum-Converted-Canon-EOS-7D-Mark-I-DSLR-Camera-UFO-Ghost-UV-IR-Astro/183198817778?hash=item2aa7801df2:g:HmgAAOSwihVb7qz-

 

and it says that, the wavelength ranges is from 300 to 3000nm, then is it fake ranges? (because it would be fantastic to me, but I always read that I need a SWIR camera:))

That is the transmission of the filter they use. A typical silicon sensor camera can see up to 1100-1150 nm.

 

Lamps: halogen, leds

https://chsopensource.org/infrared-photography-ir/

I found this led light:

https://www.amazon.com/gp/product/B07NKT8VC7/ref=ox_sc_act_title_1?smid=A2U3HRVGBEQ59&psc=1

but they said that Its maximum wavelength is 950nm only

which halogen lamp would be good?

and maybe It is totally wrong but I asked about the infrared lamps too, for example:

https://www.amazon.co.uk/Beurer-IL11-Compact-Infrared-Lamp/dp/B000KKEFVK

and they said it is between 800nm and 1500nm

or this one:

https://www.amazon.com/Beurer-Infrared-Increases-Circulation-IL50/dp/B00IVPMZKE/ref=sr_1_1_sspa?dchild=1&keywords=Beurer+IL50&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUjYxVzQxTDcyM0wwJmVuY3J5cHRlZElkPUEwMzM0NTE3MVpBVjBMS0xWRU5UNCZlbmNyeXB0ZWRBZElkPUEwNzkzMDYzMlA2QTE5SUpEUk5FViZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

from 500nm to 2500nm

I think any sufficiently powerful light source will work for you. You need a longpass filter if you use a halogen lamp, but you don't need it with IR LEDs, you just need to be in the dark. You can buy IR LEDs in a variety of wavelengths, usually from 730 nm to 1050 nm with increments of 30-50 nm.

 

somewhere I read that there is an alternative filter: old floppy disk also would be good for infrared, but I don't know what wavelength this is:)

Yes, a floppy disk should work, never tried it (I have a few 1.44 MB floppies but I will not open them), and probably they cut around 700 nm, similarly to a Hoya R72. I too tried making a DIY IR filter with black pen ink sandwiched between two clear plastic sheets, you can see my results here.
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Also the sensitivity of a full-spectrum camera often drops significantly past 900 nm. A 850 nm LED will appear much brighter than a 940 nm one, at the same output power. Past 1000 nm, you have very little sensitivity.
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Yeah, silicon sensitivity drops very fast in the 1000+nm range. You may see me mention taking photos at 1500nm sometimes but I have a germanium-on-CMOS camera that I use for those. Germanium sensitivity does not cut off until 1600nm or so.
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Thank you Stefano:) It was very helpful to me, I checked your photos, and I really like that your photos are blurred a bit, It would be a cool effect in a horror or sci-fi movie

I think I will buy leds from 730 to 1050nm

 

I found a chart about it:

Cadmium sulfide 300-850nm

Silicon 190–1100nm

Germanium 400–1700nm

Indium gallium arsenide 800-2600nm

Lead sulfide <1000-3500nm

Inidium antimones 1000-8000nm

 

but I found on Alibaba, some leds over 1400nm, those ones would be good if I could buy a germanium-on cmos camera?

these ones:

https://www.alibaba.com/product-detail/Infrared-Through-Hole-3mm-5mm-ir_62548279820.html?spm=a2700.7724857.0.0.1c595b96ikxoAf

https://www.alibaba.com/product-detail/Infrared-Nm-Led-Ledinfrared-1550nm-Led_60783788998.html?spm=a2700.7724857.0.0.1c595b96ikxoAf&s=p

https://www.alibaba.com/product-detail/Led-Infrared-Far-Infrared-Led-TO_62000231028.html?spm=a2700.7724857.0.0.1c595b96ikxoAf&s=p

I'm not sure in the last one, because it is "photo diode" and I don't know exactly what it is

 

Thank you Andy:), I read an article about it:

https://www.researchgate.net/publication/235458932_Near_infrared_image_sensor_with_integrated_germanium_photodiodes

but they also use this germanium photo diode: simple light bulb + silicon wafer + germanium photodiode into cmos process

but where could i buy a germanium-on-Cmos camera?:))

 

Thank you Colin:)

I read everything about it on this site, I downloaded their pigment tables too

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The LEDs you linked should work, but keep in mind that they are very weak. High-power SWIR LEDs emit about the same amount of light (output power) as a couple of 5 mm epoxy white LEDs, so these low power versions are as bright (in SWIR) as a green/red indication LED.

 

A photodiode is the "opposite" of an LED (even though LEDs can be used an inefficient photodiodes and vice versa), if you shine light on it in the band in which it is sensitive to (800-1700 nm in this case), you get a voltage out of it, proportional to the intensity of the light hitting it. A solar panel is a giant photodiode, and a camera sensor is made of milions of them.

 

I don't know where you can buy a germanium-on-CMOS camera, they aren't very common (and remember, they often cost several salaries).

 

If you want to shoot in SWIR and need some info, read Andy's sticky: https://www.ultravioletphotography.com/content/index.php/topic/3355-sticky-swir-photography-cams-mods-lenses-lights-links

 

Avoid line scan cameras!

 

If you are skilled, you can even build a SWIR camera with a single photodiode: http://orbides.1gb.ru/photobot.php?lng=eng

 

1000 nm may not be enough, but that's reasonably deep into IR, and deep NIR "whitens" most things.

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Currently germanium-on-CMOS are rather rare and hard to find. The more common type of SWIR camera is InGaAs, but they can’t image visible light. If you want one, this one is for sale on eBay and it looks like it probably works (judging by the video) and the guy has been trying to sell it for a long time so you might get a deal. Do NOT just pay the Buy Now price!

https://www.ebay.com/itm/333542832032

 

Please read my sticky before buying anything though (and don’t forget you may need a power supply and a frame grabber also since it’s an analog camera).

https://www.ultravioletphotography.com/content/index.php/topic/3355-sticky-swir-photography-cams-mods-lenses-lights-links/

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  • 2 months later...

Hello Teo and welcome to UVP! I hope you have been finding good information here for your needs. I think also that any art conservation website would be useful to you. This is one example I know about: http://fineartconservation.ie/

Look for the Scientific Analysis section to find more about UV/IR usage.

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  • 4 weeks later...

Thank you so much for your help:)

During camera building, I destroyed a cable, so I had to order a new one, but finally it's done

 

It succeeded, but sometimes it doesn't work (if I don't have enough pigment)

I wanted to show you some of my results

 

success: https://imgur.com/a/Mu6DidT

https://imgur.com/a/zObLoBg

https://imgur.com/a/tKUQrW5

 

fail: https://imgur.com/a/7p9SsPm

 

Thank you Andy and Stefano, It was really helpful:) I read everything you wrote,

the only problem is if there is not enough pigment, then I think an igaas camera would help, but I'm not sure

 

Thank you Andrea:) I will read it immediately

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It will be interesting to see what you will do in MWIR. The camera I found you has a "2-5 µm lens", so I guess it is sensitive in that range. If that's the case, you will have a 400 nm gap between it and your TriWave (1600-2000 nm), and a ~3 µm gap between it and common LWIR cameras (you have one), the gap being ~5-8 µm.

 

Water has a VERY strong peak at ~2950 nm, the strongest one, so It will be nice to literally see it. You can paint with water at that those wavelengths.

 

I also think you have a SWIR/MWIR/LWIR tri-color project in mind? It may be?

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Thank you so much for your help:)

During camera building, I destroyed a cable, so I had to order a new one, but finally it's done

 

It succeeded, but sometimes it doesn't work (if I don't have enough pigment)

I wanted to show you some of my results

 

success: https://imgur.com/a/Mu6DidT

https://imgur.com/a/zObLoBg

https://imgur.com/a/tKUQrW5

 

fail: https://imgur.com/a/7p9SsPm

 

Thank you Andy and Stefano, It was really helpful:) I read everything you wrote,

the only problem is if there is not enough pigment, then I think an igaas camera would help, but I'm not sure

 

Thank you Andrea:) I will read it immediately

The second example is interesting. You can really see below the surface.

 

What is your setup? LEDs, longpass filters and tungsten lamps, a combination of both?

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Andy Perrin

I also think you have a SWIR/MWIR/LWIR tri-color project in mind? It may be?

No, I don't see much point in doing a tricolor with that much wavelength separation, and it would be very difficult with the multiple resolutions and cameras to align images well enough. MWIR is interesting all by itself for tricolors because the vast majority of organic molecules have electronic transitions in that region, meaning that almost everything around us has a wildly varying spectrum and would be VERY colorful in a tricolor without much additional processing even. Just a white balance should be enough to get interesting colors in most scenes (as with visible light, in fact).

 

Honestly I don't think there's anything new to see with water in MWIR. Already in SWIR it's inky, as you saw in the ice cube melting and the evaporating heart. I think we've nearly tapped out water's spectrum, although I do have some experiments with flowers and water absorption/transpiration in mind for summer.

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Yes, you have investigated water very well. You did the 980 nm, 1205 nm, and 1450 nm peak. Steam might be the next step? There are more gases (such as carbon dioxide) that absorb there.

 

I would also like to see more black skin. I would be happy to offer as a subject, but I'm far away. In MWIR you should be able to see the fuzzy transition between reflected light and emitted light, which for people should be, very roughly, around 3 µm.

 

Warm water, as well as skin, should gradually go from black to glowing.

 

Polycarbonate should go black as it does in UV, that would be interesting too. I'm sure you will have a ton of fun.

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Andy Perrin
Stefano, let's not take over this thread. I offered the MWIR paper because it's relevant to artwork. I will do future threads on MWIR and we can discuss it there when there is more to discuss.
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Relating to this thread, I can not see the full paper, only the abstract. Does it have images? You probably can not show them because of copyright.
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