colinbm Posted October 29, 2022 Share Posted October 29, 2022 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 ? Link to comment Share on other sites More sharing options...
rfcurry Posted October 29, 2022 Share Posted October 29, 2022 I love your macro rail, Col! Structural colors are fascinating. I particularly like the UV honesty markings in some birds' plumage. Link to comment Share on other sites More sharing options...
colinbm Posted October 29, 2022 Author Share Posted October 29, 2022 Thanks Reed I based the rail on V-Slot® 20x40 Linear Rail https://openbuildspartstore.com/v-slot-20x40-linear-rail/ & their gantry's https://openbuildspartstore.com/v-slot-gantry-kit-20mm/ 'Structural Colour' is fascinating & I'll get around to looking at it in UV soon. Link to comment Share on other sites More sharing options...
nfoto Posted October 29, 2022 Share Posted October 29, 2022 Colin: your working desk looks perfect to my eyes !! I could easily substitute similar of my own working spaces .... Link to comment Share on other sites More sharing options...
Doug A Posted October 29, 2022 Share Posted October 29, 2022 Wow! Amazing macro rail and set up. Structural colors are fascinating. Looking forward to seeing more of your work. Thanks for sharing, Doug A Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Another of the Macro Rail in daylight. Link to comment Share on other sites More sharing options...
Andy Perrin Posted October 30, 2022 Share Posted October 30, 2022 Nice, that is an awesome setup! I like the photos. I wonder if Jonathan could see the actual small parts of the structures using his UV microscope — they must be spaced around 550nm since the beetle is green, so if he images in the 200nm's then that is short enough to resolve them (it must be smaller than half the spacing of the structures). You can't resolve the smallest bits of the structures in visible light. Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks everyone for looking & commenting. @Andy Perrin Thanks for this info & details. Link to comment Share on other sites More sharing options...
ulf Posted October 30, 2022 Share Posted October 30, 2022 Thank you for sharing Colin. Those dot-shaped tiny structures on the surface are interesting. The macro rail structure looks nice. I hope it is stable and resonance free enough for bigger magnifications. By using flash illumination that problem is reduced. I went down that path of photography around 2009 and then I found that quality microscope objectives often give very sharp images. One problem is to not obscure the illumination. Microscope objectives with a long working distance will be needed to not obscure the light. Unfortunately the UV-transmission of such modern and complex objectives is not good. If you want to combine higher magnification, UV and long working distance I only know of Milar- and and Luminar-lenses. Jonathan did some transmission measurements of a set of Luninar-lenses a few years ago Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks Ulf Yes the biggest problem was finding a clear bench top, I failed there. Next was a stable tripod, again I failed there too. So I tried a solid looking bicycle workshop stand, that was pretty good. I have a 4x microscope objective that goes down to about 350nm, as good as my Sigma fp gets too. I have a 10x objective coming, so hopefully just as good for UV ? I haven't evaluated the Canon MPE65mm 1x to 5x macro for UV yet ? Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 I am looking for a way to annotate these macro images with measurement units ? UrfanView can measure the number of pixels along a line, but there seems to be no way to fix this to the image. The photos from the Sigma fp are 6000 x 4000 pixels. So dividing 6000pixels by 36mm = 166pixels per 1mm. My work around was to measure the 166pixels on the photo & remember the position of the start & finish of the measurement, then to draw in a line & space of 1mm on the photo ? Link to comment Share on other sites More sharing options...
nfoto Posted October 30, 2022 Share Posted October 30, 2022 The simple solution is to shoot a ruler separately, at the same magnification. Overlay that image with your final stacked image and use that to draw the ruler in Photoshop or similar software. Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks Birna Link to comment Share on other sites More sharing options...
JMC Posted October 30, 2022 Share Posted October 30, 2022 Nice setup and images Colin. As mentioned, some of the Luminar and Milar lenses have good UV transmission if you want to go down that route. Andy, I have limited microscopy capability when it comes to reflection (and especially UV reflection). Colin's setup is much better than mine in that regard. Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks Jonathan, I'll keep a look-out for one of them. Link to comment Share on other sites More sharing options...
nfoto Posted October 30, 2022 Share Posted October 30, 2022 The best optical quality for magnifications up to say 30-50X would be with metallurgical objectives which are designed for "long" working distances. They also are small enough in front to make lighting the specimen easier for reflective photography. Unfortunately most if not all of these, such as the Mitutoyo line_up, are of the infinity optical design meaning they require a tube lens of around 200mm focal length in order to produce an image on the sensor. Tube lenses are rarely suitable for UV, sole exception is the Mitutoyo ML-4 which is very expensive. There is also the need for special versions of the metallurgical objectives suitable for UV, which drives up the cost even further. Failing the above, using the old Luminar and Milars would seem to be a much better solution. Canon long time ago had a 20mm f/3.5 Bellows lens for 10X magnification that apparently does well in UV if you don't require going below 350nm. The enlarger lenses we use for UV tend to have longer focal lengths and thus demand very long bellows draw if 5-10X is required. Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 I appreciate the extra info Birna. Yes bellows & tubes run out of light quickly. It would be magic if I could find a 20mm f/3.5 Bellows lens for 10X . I have seen metallurgical objectives but had no idea what the difference was, so now I know thanks. Link to comment Share on other sites More sharing options...
nfoto Posted October 30, 2022 Share Posted October 30, 2022 Be aware that microscope objectives not of the infinity type always assume the final optical corrections are performed by the ocular eyepiece. Thus using them directly on a bellows will often lead to inferior performance. These objectives have a very short working distance.. They also assume a cover glass is used otherwise spherical aberration is introduced. Metallurgical optics (and bellows lens heads for photomacrography) are free of this restriction. Microscope objectives are usually engraved with magnification, numerical aperture N.A., tube length (160-200mm for compound microscopes, infinity symbol for infinity focus systems), and cover glass thickness, typical 0.17mm. As to the reason why bellows and tubes 'run out of light quickly' is that the effective aperture feff is a function of image magnification. The simplified equation feff=f*(1+M), where f=aperture number and M=magnification, is often used. Thus, at 5X (M=5), a nominal f/2.8 for infinity focus becomes f/17. Link to comment Share on other sites More sharing options...
colinbm Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks Birna I have found & ordered a Canon 20mm f3.5 bellows lens This makes it look good,,,,,, https://www.closeuphotography.com/canon-macrophoto-20mm-lens Link to comment Share on other sites More sharing options...
ulf Posted October 30, 2022 Share Posted October 30, 2022 1 hour ago, nfoto said: Be aware that microscope objectives not of the infinity type always assume the final optical corrections are performed by the ocular eyepiece. That is not completely true. Several of Nikon's not infinity type microscope objectives do not need ant final correction in the eyepiece and can project the image directly onto the sensor with good results. Also the designs are optimised for visual and outside that it is impossible to tell anything about corrections. I have tentatively checked the transmission of a few of my Nikon microscope objectives, a few years ago, both some with a designed tube length of 160mm and 210mm. They do not have a good UV reach. An old Vickers objective went deeper, but the image quality is not at all that good for that one. One thing that is nice with the Canon 20mm f3.5 bellows lens is the adjustable aperture. That is a rare feature for microscope lenses as they normally have best resolution at their fixed full opening. Link to comment Share on other sites More sharing options...
nfoto Posted October 30, 2022 Share Posted October 30, 2022 OK, substitute 'always' with 'most' and we agree. As to cover glass, I have had bad experiences using any cover glass with my Mitutoyo objectives. Severe spherical aberration and coma became annoying. Link to comment Share on other sites More sharing options...
photoni Posted November 1, 2022 Share Posted November 1, 2022 it is a very difficult job . Bravo ! Link to comment Share on other sites More sharing options...
ulf Posted November 1, 2022 Share Posted November 1, 2022 On 10/30/2022 at 6:19 PM, nfoto said: As to cover glass, I have had bad experiences using any cover glass with my Mitutoyo objectives. Severe spherical aberration and coma became annoying. The Mitutoyo objectives are designed for usage without any cover glass, just as the Nikon M Plan objectives are. When the NA goes up the problem with unwanted cover glass and spherical aberration increase dramatically. Objectives designed for a typical cover glass thickness and an NA up to 0.25 - 0.30 work reasonably well without a cover glass. It is the high magnification objectives, with higher NA and resolution where this becomes a problem. There are Microscope objectives especially designed to work through cover glass or even thicker windows. Some have that function adjustable. They are often designed for VIS only. Link to comment Share on other sites More sharing options...
ulf Posted November 1, 2022 Share Posted November 1, 2022 Here are some useful webpages for increased understanding of NA: https://www.microscopyu.com/tutorials/nuaperture https://www.microscopyu.com/microscopy-basics/depth-of-field-and-depth-of-focus https://www.microscopyu.com/microscopy-basics/resolution Link to comment Share on other sites More sharing options...
colinbm Posted November 1, 2022 Author Share Posted November 1, 2022 Thank you Ulf Link to comment Share on other sites More sharing options...
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