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I've been playing around with building a UV microscope over the last year or so in between paid work (thanks Covid), which has been a fun build but very challenging. Most of my work with it is on sunscreens for a client and I cannot share those images yet, but I thought I would share a couple of of quick images of a diatom, from a Diatom Lab 2.0 test slide (see here - http://www.diatomlab.com/diatom-test-slide-version-2.0.html) The microscope is based on an Olympus BHB, and I've swapped all the glass in it for fused silica. In theory it can image down to about 250nm, but I'd need different camera/filters/light etc to get that low. With my setup I can image down to 313nm. I used a 100x NA0.85 Zeiss Ultrafluar objective, with glycerine immersion, and imaged using a monochrome converted Nikon d800. The images are stacks for 5 individual photos. The images were 'cleaned' (although looking at them now, not very well I hasten to add) and sharpened, but treated equally. The test slide mounting media lets some UV through, but is only good for 365nm (it is pretty much opaque below that). So I did visible (filtered 546nm light) and 365nm from a mercury xenon lamp. I thought I'd image Diatom 3 from the slide, which is Gyrosigma reimeri, and has about 18-22 longitudinal striae per 10um, or in other words about 500nm per striae. This is a severe test even for a high magnification, high NA objective, so should give my home built microscope with a 100x NA0.85 a real challenge. UV transmission microscopy was first developed in the pursuit of resolution, as resolution is directly related to wavelength. As such I expected the UV image to be higher resolution. Firstly, the visible image (546nm). This is the whole frame of the image. In visible light the striae are barely visible, but can just about be seen in the middle of the diatom. Secondly at 365nm, again as a full frame image. At 365nm the difference is pretty striking and the striae become visible. Cropping the 365nm image gives the following. Counting the striae gives 9 over the 5 micron distance or about 18 per 10 micron which is in keeping with the quoted number from the maker of the slide. It's a shame the mounting media in the test slide blocks the shorter wavelength UV, otherwise I'd try it at 313nm as well.

Spent some hours in my usual spot, the local Botanical Gardens, in order to take a few pure IR-shots, for a change. Equipment: Canon EOS 6D, converted to 700nm, Canon EF 85mm f/1.2, with an extension tube, used mostly at f/1.2, because, after all, if one wants shallow DOF, what's better than a fast prime and an extension tube, right I've kept ISO to 100, and the time was anything between 1/160 s and 1/4000 s, because it was quite variable with sun, partly cloudy, fully cloudy; sunny and shady bits of the Gardens, etc. I have no clue whatsoever which plant I was taking photos of, and yes, this is nothing unusual for me, but this time around I really didn't care, because I was just looking for interesting details. Post was also minimal, using the CLiR-profiles with some adjustments, just the ones with the got a somewhat better treatment, and on those I used f/2.5 (spider) and f/4.5 (bee/fly/...).

First a UVC warning - UVC is dangerous. The author does not recommend trying to replicate these experiments without knowledge and use of the proper safety equipment and procedures. This thread will cover information about an experiment I'm doing which is at an early stage. With my UV microscope I've been using it at 365nm and 313nm and it has been fine with those wavelengths. When I built it, I made sure components were used which would be usable down to 250nm, and perhaps even a little lower. However at that time, I didn't have a suitable light source, and my filtering and even camera choice made any experiments down at 254nm impractical to attempt. A couple of weeks ago I was chatting with a couple of folks on here, to try and get some advice with regards to a UVC LED source I was thinking of buying. I was steered away from my original idea, and towards trying a 3W UVC lamp as it was potentially small enough to use with my microscope. Thanks to Andy and David for taking the time to discuss things with me. The aim of this thread is to provide a bit of an update to what came of those discussions, and share some very early results of UVC microscopy at 254nm. The light source is a 3W low pressure mercury lamp source from China over ebay, cost about 8USD. I ended up mounting this in a spare Olympus lamp holder I had, after removing the internal glass lens and IR blocking filters. As result the 3W lamp was used as is, no collimating, no filtering, no anything. The camera I used was a MaxMax monchrome converted Nikon d850 with a fused silica window. I have used this before for UVC photography so know it is sensitive that far down. Filter was a 254nm one from a Sirchie forensics cameras. Again I have used this before for UVC photography. Some images of the setup etc. First, the lamp spectrum, at a distance of 10cm from the side of the lamp. The microscope with the lamp in place and switched on. And a first sample image using the diatom slide (fused silica/quartz for the slide and coverslip) using a 10x Zeiss Ultrafluar objective. I also got an image with a Schott WG305 2mm thick filter in place, the idea being to let through everything which isn't UVC (i.e. leakage from the 254nm filter). Looking at the RAW files for both images, I reckon about 90% of the image above is from the UVC and 10% of contribution of other wavelengths. This just goes to show how insensitive the camera is down there. This is very, very early days, and the method presents some very extreme challenges (in addition to safety). I need a way of focusing and collimating the light source better, as I am losing a lot at the moment. I need another 254nm filter to trying and better isolate that region. As with my 313nm work, I'd probably stack them together for better blocking. Live view focusing is currently not possible with the camera, as there is just so little sensitivity, so focusing is guesswork and trial and error. The image above was 30s at ISO1000, so it is not a fast process. I've got some 265nm LEDs on the way, so will check against the 3W low pressure mercury lamp to see how much light they are producing - maybe they will be better. Personally, I doubt they will be better, but only testing will tell. This is a bit of an unfunded side project for me, more scientific curiosity to see if it can be done than anything else (after all, the initial UV microscopy pioneers back in the late 1900s and early 20th century were doing this with plate cameras), and will update as and when I have new data/images to share. And again - just to emphasize, this is UVC work, do not try this at home.......

I just want to bring this to the attention of forum members: https://www.ksoc.co.jp/en/seihin/uv-objective/ Kyocera offers UV objectives designed for 193nm, 248nm, and a range of other extreme wavelengths. Surely these cost a fortune, but they are worth knowing about. Lou

Randon Butterfly Wing Scale @ 20x 0x Internal co-axial & external ring lighting, I need to make them both the same colour temperature.

Butterfly Wing Scale @ 100x Magnification. Showing one mutant scale amongst the black scales. I guess this is a clear colourless scale that has a regular grating pattern to give this rainbow effect ?

Pentax K-1 Kolari Vision modified full spectrum with EL-NIKKOR 80mm lens and extension tubes. Schott S8612 (2mm) and Hoya U360 (2mm). ISO 100 120 seconds at F11. Seems like ages since I had time to shoot and post here. Thanks for looking, Doug A

Butterfly Iridescent Wing Scale. Unknown species. 100x microscope objective.

The Pollen Changed Colour Overnight ? One of the pollen changed from Yellow to Cyan overnight ? Pollen at 100x magnification. The stage is smooth black anodised aluminium, but not at 100x magnification. Yesterday Today. Tonight, they are both Cyan.

A Pollen 100 x magnification + 100% crop.

I Am Gob-Smacked ! At the age of 71 & getting close to the end of my intelligent life, I am just starting to see these results. I have made some improvements with the Macro Rig & I have plenty of improvements to learn with image quality, I hope I can get there. Here we have the surface of the Poor Old Faded Matchead, viewed at 100 x magnification ! 150 images at 1.125um each step, stacked with Zerene Stacker, that makes the depth of approx 0.017mm.

Kookaburra Feather, full size & 10 x magnification.

What is the Good, the Bad & the Ugly of this light please ? After making my rig very sturdy & with 1.25um steps & getting suitable photos with a 60x objective, I have started getting deeper into Microscope Objective Macro Photography, now with a 100x magnification. All went OK, except the lighting for the 60x objective wasn't enough for the 100x objective. The problem is the working distance is now only 2mm, & it is hard to get a strong light in that gap. I found this LED down light to be suitable with some modifications. The LED COB in this one is 7mm square & rated at 50w equivalent. Many other specs are useful, like 12v AC/DC & either polarity in 12v DC. The Data Sheet.... https://www.ledvance.com.au/en/product-datasheet/6864/31735 The plastic lens pops out with a thin lever, revealing the 7mm Cob LED. I then added an aluminium heatsink with a 16mm tube 150mm long. I will make four of these to place close to the 100x objective.

Last year I shared a post about some initial attempts at imaging a diatom using the UV microscope I've been building - https://www.ultravioletphotography.com/content/index.php?/topic/4883-uv-365nm-and-visible-546nm-microscopy-of-a-diatom/ With that initial test I used a commercial test slide from Diatoms Labs which is a nice slide, but is made from glass and the mountant used quite strongly absorbs the UV. As such the test slide is not usable in the UVB, so was of limited use for me. Before Christmas I started asking around for someone who could make me a test slide using the quartz slides and coverslips I have, and with a mountant that would let UVB through. Quite quickly I tracked down a Diatom mounter who was intrigued by what I was after and offered to help. After a lot of experimenting on his behalf (for which I will be forever grateful) the first test side arrived today, and I wanted to share some very preliminary images. This was of one of the diatoms on the slide. These were done with with my UV transmission microscope, and with a 32x NA0.4 Zeiss Ultrafluar objective. Images captured at 546nm (visible), 365nm and 313nm using a monochrome converted Nikon d800 camera. Images processed similarly, and collected as stacks in Zerene. They have been reduced in resolution for sharing here. First, at 546nm. Next, at 365nm. And finally, at 313nm. As expected the resolution improves as the wavelength decreases. Also the 313nm image needed loads more retouching - the shorter wavelength improves the resolution, but obviously makes all the imperfections and dirt in the image more visible as well. Hence more retouching. 313nm with my 100x NA0.85 Ultrafluar will be 'fun', or should I say, 'character building'. Funnily enough the chap who made the slide for me wasn't happy with it at all, as the gelatin he used to mount the diatoms is too visible. He says he will try again with other techniques (what a nice man). I was just happy to have something that was transparent in the UVB.

Are there any Epi-Illumination systems that work with M42 x1mm pitch extension tubes please ?

60x magnification of the Green Jewel Beetle shell. I would like to say thank you to the forum members for their help & encouragement in this endeavour to see the structure of the beetles shell that gives it its iridescence. Ulf has been a great help with finding suitable objectives on ebay for me & his kind donation of a pair of linear actuators that can be manually turned at 0.00125mm or it has 200 divisions per rotation at 1.25um. This has allowed me to get 53 stacked images. I think I will need a scanning electron microscope, perhaps in another life !

I've recently been doing a bit of microscopy (bringing an old Olympus BHB microscope back from the grave), and while buying bits for it I came across an odd objective lens - the Reichert 40x reflecting objective. I was the only person to bid on it, and a few days later it arrived. It's a funny little thing. It has a dovetail mount for use on a Reichert microscope, but that mount unscrews to reveal a standard RMS screw thread. Here's the lens. Apparently designed for multispectral imaging, I was wondering what it'd be like for UV photography. I mean, what could possibly go wrong?? On the lens it says 250/1.5Qu, which as I understand it means it's meant for a tube length of 250mm and quartz coverslip of 1.5mm. I mounted it on a range of extension tubes to get me out to 250mm, and I could see..... absolutely nothing, couldn't get any focus at any distance. Back to basics, about 10mm extension and straight on to my UV modified d810. Amazingly, moving it back and forth I could see something come in and out of focus. Very quickly in and out of focus. Very, very quickly. Subject is a Dandelion and lighting using my Hamamatsu LC8 200w xenon lamp and collimating lens, setup shown below. And what did it show? Here is a UV image taken with it, full frame (no cropping) and whitebalanced in Darktable. I've upped the contrast and boosted the saturation slightly (and reduced the size for sharing), but other than that unmodified. This is part of the stamen style of the Dandelion, showing some pollen grains, with another part of the flower out of focus towards the right hand side of the image. Pretty trippy stuff, with some crazy reflections and flare. I see Enrico has written a bit about a Spectra-Tech Reflachromat lens, here, but I haven't been able to find out much about the Reichert one anywhere. It's certainly much smaller than the Spectra-Tech one, and is marked up as having higher magnification. Will it be useful? I'd struggle think how I'd use this for photography. Lighting is a nightmare, and fitting a hood would be 'challenging' to say the least. While it's marked as being designed for a 250mm tube length, I had no joy with long extensions. Depth of field is essentially zero, so stacking would be a must. I am planning on building a photomacrography rig in the future, and when I have stacking capability, I shall have another play with it. However despite all this, it is a cool little lens, so thought I would share it here.

Green Jewel Beetle with 20x Objective a big improvement from the little Canon 20x f3.5. I have changed the macro setup yet again looking for precision & stability, this is just OK for 20x magnification. Only slight movement when moving the next step in the stack which is about 0.01mm, guessing 43 steps in just under half a millimetre. This is the very limit of fine adjustment with these macro rails used here. I have a 60x objective coming & a fine 0.001mm step linear rail coming too. I will be having fun over Christmas learning & making a suitable setup for 60x macro.

I am glad that I persisted. Thanks for your help & encouragement on this forum. Still getting the shakes out of the system & very fine adjustment. The 10x microscope objective has preformed very well. This is a 1mm wide crop of the Green Jewel Beetle's shell. Only the centre strip is stacked, it was 12 stacks over about 0.1mm depth. The magenta piece seems to be dust ?

I have a Small Dilemma 20x or 2mm. I can now do macro down to 20x, that is 1.8mm on a full frame sensor. But 2mm on the sensor would make scaling measurements on the image easier. Which do I chose ?

As well as my journey with UV LED lights I have been making a macro rail set-up that suits me & is stable. The first photo is of the Macro Rail set-up at present, it can be used horizontal or vertical. Next photos are of an expired 'Green Jewel Beetle' from Sulawesi Island, the botanists call it Chrysochroa Fulminans. I purchased this beetle for its iridescence & my interest in 'Structural Colour'. The camera is a standard Sigma fp with a Canon MP-E65mm f/2.8 1-5x Macro lens. Simple processing by me & Topaz AI Sharpen & adding text in Irfanview & resizing for the web took its toll in the photo, so I also took a crop from the original DNG to see the 'Structural Colour' surface better. I have ordered a 10x microscope objective to see if I can see the structure any better ? The Macro Rail set-up at present (& one of my messy desks).. Green Jewel Beetle 1:1 full frame. Green Jewel Beetle 5:1 Green Jewel Beetle 5:1, 100% crop from the centre Green Jewel Beetle 5:1, 100% crop from the centre of the original DNG file. I think we can see the fine structure best with the individual colours diffracted from the surface ?

Adaptalux is offering a new unit on Kickstarter. It uses the same lighting arms as their studio unit. One of the packages has 365nm UV arms for UVIVF. I love my Nemo lights, but the Adaptalux would be so much easier to position. I'll probably pledge for a set. Thanks, Doug A

The Green Iridescent Jewel Beetle wants to see its audience & in UVIVF too. The beetle will go back into hibernation till I get a 60x objective setup. Here are two head shots, one in visible light & one in UVIVF. Sorry the UVIVF is a bit primitive, but so am I, I did my best to clean up a messy background. They say you can make a piece of coal fluoresce given enough UV light !

I think I have reached the limit, with this macro rail, camera & lens. 20x macro is demanding, 20mp Sigma fp, Canon 20mm f3.5 on 430mm tubes & the Nisi macro rail, have done their service admirably, for single shots. There is just too much flexing & vibrations in the system for photo stacking. A much sturdier & refined system is needed if I want to see the structure of 'Structural Colour', I think. Here is my latest photo with the set-up I have, it is a single shot of a steel ruler showing a 1mm division. It shows a lot of dirt particles, that aren't apparent to the eye.

Green Iridescent Jewel Beetle's Shell at over 20x Magnification. I added some baffles into a long extension tube to cut some flaring. When I re-assembled the tubes I accidently added the remaining few extensions I had & now the tube is 430mm long ! Getting a bit out of hand, but it works ? Canon 20mm f3.5 Macro Bellow Lens.....the little big lens that can ! Green Iridescent Beetle at over 20x Magnification. The picture is of a 1.5mm x 1mm section of its shell. 19 stacks in Zerene Stacker with DMap.