Quick question - is ZWB3 really passing UV from about 230nm?

[Forensic_Photographer]

Thanks Ulf :)

 

The camera is a modified Canon R5 and we use Kolari drop-in filters ("quartz clear" for UV and "hot mirror" for normal photography)

We use a canon-nikon adapter and a Nikon quartz lens with Baader U filter for UV 365nm photography.

 

We are going to try to get some results in shortwave UV with the above filter and a UVC light source (we dont have one at this point) - perhaps a cheap UVC germicidal light bulb ? Or maybe some kind of UVC Flashlight ?

 

Or do we need something better such as a Spectroline ?

 

Since we dont know what the R5 sensor is capable of in shortwave UV we are not spending that much money at this point.

 

Then we are going to compare the results from our 365nm and 254nm (if any) photography with forensic equipment for shortwave UV from Ruvis and Arrowhead

 

 

[colinbm]

What are the prices on these cameras ?

 

[Forensic_Photographer]

Unfortunately, the forensic cameras from Ruvis and Arrowhead are priced between 50.000 - 100.000 US $

[ulf]

3 hours ago, Forensic_Photographer said:

Thanks Ulf :)

 

The camera is a modified Canon R5 and we use Kolari drop-in filters ("quartz clear" for UV and "hot mirror" for normal photography)

We use a canon-nikon adapter and a Nikon quartz lens with Baader U filter for UV 365nm photography.

 

We are going to try to get some results in shortwave UV with the above filter and a UVC light source (we dont have one at this point) - perhaps a cheap UVC germicidal light bulb ? Or maybe some kind of UVC Flashlight ?

 

Or do we need something better such as a Spectroline ?

 

Since we dont know what the R5 sensor is capable of in shortwave UV we are not spending that much money at this point.

 

Then we are going to compare the results from our 365nm and 254nm (if any) photography with forensic equipment for shortwave UV from Ruvis and Arrowhead

 

 

Is the Canon R5 monochrome converted?

 

If it still have the Bayer (RGB) array it is extremely unlikely ≈0, that any image you get show an image caused by 254nm.

You might get an image, but that will be formed with light of longer wavelengths.

 

Even with a monochrome converted camera it is very difficult and you will need to block all longer wavelengths extremely well. 

A cheap germicidal lamp emit rather much light beside the 254nm peak.

 

There are a few members here that have worked with that problem to find out what is needed to take real 254nm images.

Lukasz that started this thread is one.

Jonathan (JMC) has worked a lot with this problem too. He is professionally deeper into research in this area. If you do some searches on this forum there is much to learn.

[Forensic_Photographer]

Our cameras are not monochrome converted.

 

We will probably still do some tests and see what we find since the effects we are looking for not necessarily is at 254nm.

 

56 minutes ago, ulf said:

If you do some searches on this forum there is much to learn.

Thanks, will look into it :)

[dabateman]

6 hours ago, Forensic_Photographer said:

Our cameras are not monochrome converted.

 

We will probably still do some tests and see what we find since the effects we are looking for not necessarily is at 254nm.

 

Thanks, will look into it :)

It doesn't hurt to test it as you have a filter and a cheap germacidal bulb isn't too expensive.  I am guessing your in a lab. Do you have a quartz cuvette and some pure acetone?  Acetone will be dark in the UVC, and little in UVB range. Compare it to water or pure Isopropyl alcohol,  which will be clear. There might be another good solvent to test, but acetone isn't too expensive and you might be able to buy it.

 

[Forensic_Photographer]

On 7/16/2023 at 1:37 AM, dabateman said:

It doesn't hurt to test it as you have a filter and a cheap germacidal bulb isn't too expensive.  I am guessing your in a lab. Do you have a quartz cuvette and some pure acetone?  Acetone will be dark in the UVC, and little in UVB range. Compare it to water or pure Isopropyl alcohol,  which will be clear. There might be another good solvent to test, but acetone isn't too expensive and you might be able to buy it.

 

Thanks for the tip :)

 

Will try with acetone when its time to do some testimages (and hopefully we have a quartz cuvette somewhere)

 

I am aware that I am offtopic in this thread and it would probably be best to do a new one, but I have one more question.

 

Is it correct to assume that the best choice if we want to get result in shortwave UV is to buy a modified camera from maxmax.com ?

 

The version called "Monochrome UV-Only" ?

 

I am aware that its no guaranty that we will se anything at all under 300nm, but its still the best option short of investing in one of the forensic cameras linked above ?

 

We are thinking of sending a camera from us or buying a pre-modified directly from maxmax. 

 

[lukaszgryglicki]

I don't have any real success with 254nm light so far, the biggest issue is blocking everything else... I'm able to record "something" but this looks like light leaks rather than real UV-C image.

 

[ulf]

16 minutes ago, lukaszgryglicki said:

I don't have any real success with 254nm light so far, the biggest issue is blocking everything else... I'm able to record "something" but this looks like light leaks rather than real UV-C image.

Thanks Lukasz for the comment.

I also want to clarify for others, that this is with your advanced monochrome converted camera and when using stacks of expensive advanced filters on your UV-Nikkor.

[lukaszgryglicki]

This is all true also when I was using 4 x 25W UV-C bulbs.

Blocking blocking blocking... and lack of real good filter, those special filters for 254nm seem to be direction-dependent and leak IR badly and even red badly.

I will have to find time and try to repeat my experiment because, with my recent UV-green, I've figured out that not only the hood can cause reflections but also lens mount conversion from GFX to Nik-F.

I think I need to try in total darkness too - like in the middle of the night indoor behind the closed door.

 

[ulf]

36 minutes ago, lukaszgryglicki said:

This is all true also when I was using 4 x 25W UV-C bulbs.

Blocking blocking blocking... and lack of real good filter, those special filters for 254nm seem to be direction-dependent and leak IR badly and even red badly.

I will have to find time and try to repeat my experiment because, with my recent UV-green, I've figured out that not only the hood can cause reflections but also lens mount conversion from GFX to Nik-F.

I think I need to try in total darkness too - like in the middle of the night indoor behind the closed door.

 

All dichroic filters are more or less direction sensitive.

That is true also for a Baader U that is more sensitive to stray light and benefit more from a lens hood than an ionic filter.

 

When extreme blocking is needed like for UV-C the direction dependency becomes more stringent.

Those filters are designed for scientific setups with mainly parallell beams passing the filter.

[ulf]

On 7/15/2023 at 3:27 PM, Forensic_Photographer said:

We are going to try to get some results in shortwave UV with the above filter and a UVC light source (we dont have one at this point) - perhaps a cheap UVC germicidal light bulb ? Or maybe some kind of UVC Flashlight ?

 

Or do we need something better such as a Spectroline ?

 

Since we dont know what the R5 sensor is capable of in shortwave UV we are not spending that much money at this point.

 

Then we are going to compare the results from our 365nm and 254nm (if any) photography with forensic equipment for shortwave UV from Ruvis and Arrowhead

Normally when discussing UV-C illumination, the topic shall have a clear warning text, but this topic has drifted.
I hope you know and have read all the warnings about the elevated dangers from short wave light sources and how to properly protect yourself.

If not please search for other topics and learn how to protect you if that knowledge is lacking.
 

A 254nm light source is vastly more dangerous than a 365nm lamp emitting the same optical power.

 

According to the UV Hazard table in 254nm light is more than 4500 times as dangerous as 365nm light

( From the safety standard IEC 62471 Photobiological safety of lamps and lamp systems )

 

Such standards can be bought and if you are serious lab you might already have access to it. 

I can help with some interpretation if needed.

[Forensic_Photographer]

15 minutes ago, ulf said:

A 254nm light source is vastly more dangerous than a 365nm lamp emitting the same optical power.

 

We are aware and we already produce many of our photos in protective clothing (coat, gloves, facemask etc) - to protect ourself, but also to protect what we are taking photos of from contamination.

 

For our small UVC experiment we have already aquiered plastic face shielding and extra arm-protection - we do have experience from operating a RUVIS system.

 

Before the end of the summer I will probably have taken test-images with both the RUVIS system and the FSIS II from Arrowhead, in 254nm - the idea is too see if we can recreate similar results (or  come close)- with a converted Canon camera and a quartz lens (we have the old UV-Nikkor 105mm 4.5 lens and a Coastal Optical 60mm 4)

If its not possible we will probably ask for money to invest in one of the forensic cameras. 

[dabateman]

The Coastal 60mm f4 can just see UVB, not UVC. Its cut off is around 300nm. It was optimized for sharpness,  not UV reach as consulted with Birna.  

But you do have a UV Nikkor, which will work.

Does your RUVIS system have a C-mount and removable 254nm filter?

If a C-mount you can get a C-mount to F-mount adapter to see what it looks like with the Nikon lens.

The 254nm filter, if removable is a great option for UVC imaging. 

 

Depending on your budget and grants and how much work you want to put into imaging.  The best cheapest option is a MaxMax monochrome converted piHQ camera sensor. You then need a Raspberry pi board, software is free or you can develop your own.  You also need a really good filter. The Nikon 105mm can be adapted to the C-mount of the piHQ camera sensor, with similar field of view as to your RUVIS. Or you can buy a lenses from MaxMax with the piHQ camera sensor. 

Really the hardest part about imaging in UVC is getting a really good filter. 

 

If your grant is large than you can just buy the expensive forensics kit.

[Forensic_Photographer]

15 minutes ago, dabateman said:

The Coastal 60mm f4 can just see UVB, not UVC. Its cut off is around 300nm. It was optimized for sharpness,  not UV reach as consulted with Birna.  

But you do have a UV Nikkor, which will work.

Thanks, yes - I remember reading somewhere that the UV Nikkor had a larger range :)

17 minutes ago, dabateman said:

Does your RUVIS system have a C-mount and removable 254nm filter?

We do not have a RUVIS system now, but we have been able to do some test on one.

19 minutes ago, dabateman said:

Depending on your budget and grants and how much work you want to put into imaging.  The best cheapest option is a MaxMax monochrome converted piHQ camera sensor. You then need a Raspberry pi board, software is free or you can develop your own.  You also need a really good filter. The Nikon 105mm can be adapted to the C-mount of the piHQ camera sensor, with similar field of view as to your RUVIS. Or you can buy a lenses from MaxMax with the piHQ camera sensor. 

Really the hardest part about imaging in UVC is getting a really good filter.

We do however still need raw files with high resolution.

 

22 minutes ago, dabateman said:

If your grant is large than you can just buy the expensive forensics kit.

Its a possibility and it will take some time - but we can only afford one :)

We have multiple stations for photography today and we are many photographers - this solution could open up for usage on more than one of the photo-stations.

We also love the (free) Canon "EOS Utilty" software were we can control the camera from a computer with liveview.

[dabateman]

What is high resolution? 

The Raspberry pi HQ sensor is 12Mpixels. Also being a Raspberry pi you get true real raw data. The newest OS can save a DNG for every captured image. 

Raspberry pi cameras are also typically used remotely for Astrophotography and wildlife camera traps. So remote is an option and the boards have wifi and Bluetooth. 

But really the problem will be to source a great filter. If you can only get a good filter with an optimized Forensics system,  than that might be your best bet.

[Forensic_Photographer]

1 hour ago, dabateman said:

What is high resolution? 

The Raspberry pi HQ sensor is 12Mpixels. Also being a Raspberry pi you get true real raw data. The newest OS can save a DNG for every captured image. 

Raspberry pi cameras are also typically used remotely for Astrophotography and wildlife camera traps. So remote is an option and the boards have wifi and Bluetooth. 

But really the problem will be to source a great filter. If you can only get a good filter with an optimized Forensics system,  than that might be your best bet.

I think we need at least 20Mpixels, but the Raspberry pi is more capable than I thought - will look into it, thanks :)

 

I dont know what filter is used for 254nm in the RUVIS or Arrowhead system, but I will take a closer look when I see the equipment and ask if its possible to buy separate parts.

 

However, from what I have seen I think it is a sliding filter that probably only fits this special equipment.

 

Edit:

 

This is the lens that is used in RUVIS - the filter slides in front of the optics:

 

https://www.resolveoptics.com/228-000-60-mm-f3-5-uv-forensic-lens/

[dabateman]

Ok thats the lens I have (or the knockoff version as mine may not be a true Resolve lens) . There is a filter slider that holds two filters, a glass lp300nm filter and a 254.6 bp filter for UVC imaging. The filters are actually behind all the optics of the lens, but part of the optical path. The filters are 25mm that fit into the holder.

 

 

[Forensic_Photographer]

4 hours ago, dabateman said:

Ok thats the lens I have (or the knockoff version as mine may not be a true Resolve lens) .

 

This one ?

 

 

Could be Resolve Optics.

I think it was originally made to be used handheld for searching crime scenes.

 

4 hours ago, dabateman said:

There is a filter slider that holds two filters, a glass lp300nm filter and a 254.6 bp filter for UVC imaging.

 

Yes, found a good image of another lens with a 254nm and a 445nm filter.

 

 

4 hours ago, dabateman said:

The filters are actually behind all the optics of the lens, but part of the optical path.

 

Yes, meant to say that - sorry, language problem :)

 

I got a really nice mail from Dan at maxmax.com that explained the technical aspects closer - a Canon camera is probably out of the question.

 

The Raspberry Pi looks like a good option and I think we have a Nikon D8X somewhere, will look for it at work today.