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UltravioletPhotography

60mm f3.5 C mount UV lenses on eBay


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EDIT: 13th September 2019. These lenses apparently aren't original Resolve Optics 60mm ones. They were reverse engineered by another company.

 

Currently on ebay there is a company selling second hand forensics imagers called Sirchie Krimesite cameras. As far as I can tell, they are using the 60mm f3.5 Resolve Optics UV lens shown here;

 

https://www.resolveo...-forensic-lens/

 

The ebay link is here;

 

https://www.ebay.co....~0AAOSwHcNc-TVG

 

They have a variety for sale, including full forensics setups, but the one in the link above is cheaper than a full setup and includes the filter holder (which some of the others don't have).

 

I spoke briefly with Resolve Optics earlier, and asked about a new price for one of their lenses. They did not want to give that info out, however when I asked if it was more than £1000, the answer was, "oooh yes".

 

I have no affiliation with the ebay company selling these, however I have bought one myself (which I wont see until November when I next see my family in the US). They accepted an offer of $700 for one.

 

I'm sharing in case it is of interest.

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Thank you for the link.

Here is a brochure for what they are selling:

http://www.suelee.ca/media/03_ruvis_1.pdf

 

Its a KSS60 Imaging system. It has a quartz lens and P22 phosphor imaging to take reflected UV-C (254nm) light and convert it into visible light. The device can accept cameras on the back to photograph the green visible interpretation of the UVC. But they don't include the camera adapter.

 

This lens is capable of focusing down 23cm and has a 30.5mm front filter. It also looks to me like its really a T-mount lens with a T-mount to C-mount filter slider adapter to hold the visible and UV filters. The KSS8010 comes with different filter options. It can hold 25mm filters up to 5mm thick.

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Andy Perrin
I threw my hat in the ring for one of them too. Thanks, Jonathan. If I don't get it, I'll look forward to your review!
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Andy,

How do the phosphor detectors work for SWIR. I wonder if this detector with P22 phosphor can detect in the SWIR range as well as the UVC range.

If you get one I would be interested in you testing with your filter.

I only have a LP1100 filter.

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Andy Perrin

No, it won't work for SWIR, which needs an UPconverting phosphor, not downconverting. Totally different chemicals and different physical mechanisms also! But the image intensifier tube should work for both, and you could just buy a SWIR phosphor screen. I believe MaxMax sells the SWIR phosphor material. I do plan to see if I can rig up a portable SWIR setup.

 

And yeah, I got one. It's C-mount, so it should work nicely with the TriWave, although I'm sure it will be like looking through a microscope. Which could be fun...

 

I'm not sure how much of my full frame A7S that quartz lens will cover, but it will be fun to find out.

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Andy the lens specs say it resolves 32 line pairs per mm with image circle of 17.5mm.

So if it can mount too a m43rds camera, then it should cover that sensor.

But I am worrid it may not fit a c-mount adapter, as the lens is 54.8mm in diameter. My adapter allows a 52mm diameter lens, so I hope it has enough protusion or is really a Tmount lens with a cmount filter slider.

I will let you know, I got one as well.

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I'm interested but wtih a 17.5 mm circle that is pretty bad vignetting on an apsc sensor.

but doesnt' the image circle increase with magnification. Gosh my physics is rusty. so might make a good macro lens

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If you move a lens further away from the sensor, into macro, then yes the circle increases. However, there will be a limit as to the distance you can do that to still get a sharp image.

Also depending on how the lens is designed stoping down will also increase the image circle. Thus why really fast lenses vignette a lot and stopping down to say F5.6 clears that.

 

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Andy Perrin
It’s really not so much that you increase the image circle by stopping down as that you stop the center being so much brighter than the edges due to cosine falloff by restricting the range of angles of light that get in.
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swir is thermal imaging right? why do you need a quartz lens for that? I thought one could use regular glass?
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Andy Perrin

No, SWIR is not thermal imaging (that’s LWIR). SWIR is in between the LWIR and NIR (the part that’s next to visible light that you can image with silicon). But actually it’s not the lens I want for SWIR, it’s that image amplifier setup. I will use a lens designed for SWIR with it, and another phosphor screen made for SWIR.

 

I’ll use the quartz lens for UV on the TriWave (which covers UV-SWIR).

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Andy did you get yours yet?

What color are the slide filters?

My lens has seperation at the aperture ring. Is yours tight?

 

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Andy Perrin
I got it but haven’t even had time to open the package yet! I’ve been working all day. Sudden run of new students frantic about finals.
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After some tests I am a little happier.

The lens has issues on mine. It wobbles significantly at the point between the aperture ring and the filter slider. This causes focusing issues. Mine may not be usable outside, with any wind vibrations. But in the basement, I can just get it steady.

It has major focus shift between wavelengths. Mine has a front 37mm thread, which is good as I have an extra 37mm to 52mm stepup ring.

The lens base is really wide, so will not fit a c-mount adapter. Fortunately, I have a c-mount to m42 adapter, then use that to M43rds. This is macro only. At infinity though, I get about 10 to 15 feet in focus in visible light. Also in this setup it fully covers the M43rds sensor. No sign of vignetting at f3.5.

 

My filters are what makes me happy. The clear one allows 313nm to transmit without too much penalty. The silver mirror filter is interesting, it has the best IR blocking I have seen. Just get an image with PTFE Hallogen lamp at F4, 60sec and ISO 1600. And not a good image.

It also blocks most UV. Get poor image with UVB bulbs and Baader venus U filter, at F4, 15sec and ISO1600. Similar poor image using 313nm filter.

But flip to using my super dangerous 254nm UVc light and you see something. Even with the EM1mk1. At F4, ISO 1600, 5seconds, you get a cloudy mist. My lens is really hard to focus as seems to be broken. But flower is jet black, and PTFE is reflective. Oddly though its more blue down there. I was expecting red from my 280nm tests. And I know its not IR leak from IR tests. So not sure exactly what I am seeing. Need to stack filters to see if IR leak with 254nm. I don't like to use that bulb for long as the ozone really builds up with it.

 

Using it as intended, you see stuff through back with both 254nm light and UVB light. Its a monochrome green world, as that is probably the only phosphor used.

Hard too focus and UVc wants you super close.

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Just catching up on the forum. What I'm reading on the lens is now concerning me. None of these issues were mentioned in the advert. David are you going to send yours back - they mentioned a 30 day returns policy from what I recall?
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Andy Perrin

I opened up mine now. It appears in good condition, nothing broken. The lens is pretty awful in visible spectrum — I've seen toy cameras with this much fringy CA! Which the image rather resembles. But it clearly was meant to use visible just for adjusting focus and so on, not actual picture taking. I do not have a UV-C light source so I have no way to test it for that purpose. The image does vignette on my full frame Sony A7S, which is to be expected, but other than that it's fine. I'm quite curious what results I'll get in UV-A once I swap out the UV-C filter.

 

ETA: some pics.

 

This is my attempt at infinity focus using the visible filter it has in there on my converted Sony A7S.

 

Whole image, reduced size. This gives the size of the image circle, as seen on this full frame sensor. There is a bright spot in the middle that I am not sure of the cause of.

post-94-0-96163300-1564344899.jpg

 

Center crop:

post-94-0-43707700-1564344970.jpg

 

 

Top center crop:

post-94-0-50992700-1564344982.jpg

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wow even has a nice hot spot like the coastal optics?!>!> :P :excl: :wacko:

I offered $700 to the seller for the lenses they still have for sale without the filters, they must of gotten greedy because they declined.

I do not have a uvc light source either, so maybe the filters included would be basically useless to me.

thanks for testing it out so far, hopefully the uva results are better, right now looks like a lemon to me.

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Andy Perrin

Well, it’s certainly not optimal for visible light photos. You could focus in visible but that’s it. I can’t test in UV-A yet because those filters are screwed in with a hex screw so small I don’t own a screwdriver to remove them. Waiting on Amazon to send me a set of very tiny hex screwdrivers.

 

ETA: So, I discovered that the "hotspot" problem I was having earlier was caused by a mix of no lens hood + crazy dispersion in infrared. This lens does NOT WORK in infrared, from what I've observed so far, at least not in a broad spectrum image. (It might be okay for a very narrow band of IR.)

 

Here is an image of a flower using an incandescent flashlight filtered with 1.75mm S8612 so it's all visible (and maybe a tiny bit of UV).

post-94-0-00189000-1564370924.jpg

 

Crop:

post-94-0-40744300-1564370934.jpg

 

Still not the sharpest lens in the drawer, but at least it's not as bad as it first appeared.

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Andy,

What is the front filter thread on your lens?

Mine was 37mm, the clear filter in the slider seem to transmit some UV.

Did it mount directly in a c-mount to E-mount adapter? Or did you need to modify it?

Are your filters in the slider clear and silver/mirror?

 

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many aluminum black anodized lenses use a black dye that is basically transparent in infrared , so the inside of the lens is basically a bright reflective metal surface, which causes flare and ghost spots like you describe andy.

looks like shooting macro doesn't make the image circle that much bigger, oh well, can just crop on apsc body.

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Andy Perrin

Mark: Well, I have plenty of black material to line it with, I guess, if that’s the problem. I could easily check by taking a photo of the lens in IR.

 

Dabateman: not sure on the filter thread, no modification needed for mounting on my A7S (the usual adaptor from Fotodiox worked fine), and yes, I have the same two filters in the little slider tray.

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Andy Perrin

Ah hah, score one for you, Mark: the inside of the barrel is very shiny. Paint still looks pretty dark in IR, but I do think the shiny inside barrel is the issue. I have some Acktar Metal Velvet that I can line it with; that stuff is one of the "ultra dark" materials, so it should do the job across the spectrum. Probably the shininess is irrelevant in UV.

 

With Hoya R72 (720nm longpass):

post-94-0-66973300-1564420207.jpg

 

Dabateman: I measured the filter thread diameter with calipers, and it seems to be 36.5mm.

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you might want to take a photo of that dark felt, as you know many synthetic fabrics are very IR reflective. I remember bulk loading 70mm IR film back in the day and I would take photos of the film canisterss in NIR, some were black others had basically white felt linings .

 

do you think it is worth $750? without filters and tray? that is lowest seller is going on current auction. It will be probably my only opportunity to own a real quartz lens that doesnt' cost several thousand.

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Andy Perrin

Metal Velvet isn’t velvet! It’s a brand name. Google Acktar Metal Velvet.

 

do you think it is worth $750? without filters and tray? that is lowest seller is going on current auction. It will be probably my only opportunity to own a real quartz lens that doesnt' cost several thousand.

If you want it for UV-C, possibly. For general UV-A shooting, at the moment I’m leaning against it. But I still can’t test it there yet.

 

You should really buy an EL-Nikkor 80mm/5.6 metal version before you start thinking about quartz. The EL-Nikkor is a wonderful sharp lens with a bandpass out into the 340nm+ range (depending how you quantify the cutoff).

 

 

Here is the lens without Acktar (in near IR 720nm+ longpass):

post-94-0-54973800-1564432457.jpg

 

Here is the lens WITH Acktar (in near IR 720nm+ longpass):

post-94-0-77679500-1564432465.jpg

 

Here is a photo (F/22) without Acktar (no filter but the clear built in one):

post-94-0-01509200-1564432519.jpg

 

 

Here is a photo (F/22) WITH Acktar (no filter but the clear built in one):

post-94-0-53765600-1564432538.jpg

 

That seems to have partially fixed the problem, though I still saw some signs of the hotspot in macro. I think a lens shade will keep that in check.

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Mark,

Its good for UVb. Not so good for UVc. I will post pictures latter. But I may need to clean the filter more. But yes this will be the cheapest option that is good in UVb if yours mounts to a Sony camera like Andy. You don't need the filter slider. Just get some 3M black electical tape and seal up the side from light leaks. Just use or adapt to the 37mm front filter threads. The UVc included filter is not really worth it. And its only a 260nm filter.

 

The only other cheap option is the UKA optics 25mm c-mount quartz lens. Its around $600. But it will just cover a M43rds sensor, not APS-c.

 

Andy. Check your clear filter. Mine was covered in clearish oil. Once clean, mine seem quite sharp. I will post photos later tonight.

 

I spoke to the seller on the phone today. He walked me through step by step how to take the lens apart and fix my problem. Actually, quite simple. If anyone else gets the separation I had, I can tell you how to take it apart.

 

From tests today, my lens is actually a 75mm. The light transmission is also 1.6 stops slower than expected in visible. I measured the aperture and its the same, almost 2 stops slower than marked.

This is also why F4 is the sharpest setting on my lens. Its really about F8.

 

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