Introducing myself (from Finland)

[aphalo]

Hello!

 

I am very glad to join the group and I hope to be able to not only learn from other members, but also to contribute to the discussions. I have been a researcher in physiological plant ecology throughout my career, most of the time studying how plants use light as a source information about their environment. By this I mean for example, detecting the presence of "neighbours" by the light they reflect and triggering responses like stem elongation before they are shaded by these neighbours. I have studied the role of both UV and VIS radiation as sources of information and the mechanisms plants use to perceive UV and VIS cues and signals. As they are tasks frequently needed in this type of research I am very familiar with spectral measurements of solar and artificial light, and also with the measurement of optical properties of plants parts. We also frequently use optical filters and light sources in experiments. In recent years we have acquired for plant-related research four different array spectrometers, power LEDs, including even a couple of them emitting at 310 nm and 340 nm. Last year we had an Olympus OM-D EM-1 mirrorless camera modified to full-spectrum. I had been wanting to buy such a camera for years, but the price of the UV-Nikkor seemed too high to justify its purchase. Before buying the camera I read quite many posts at this site and Savazzi's web site and learnt about the "accidental" UV objectives. Both sites have been of great help. I am not new to photography and/or photography techniques, but I have been able to start taking UV images only about a year ago. On the other hand, photography has been my beloved hobby since childhood.

 

In addition to the camera mentioned above, we have at work a Kyoei 35mm f:3.5 in Leica LM39 mount, which is very sharp, but only so-so in UV transmission. I have a Hannimex-rebranded Kyoei 35mm F:3.5 in Minolta MD mount which has much higher UV transmittance than the one in Leica rangefinder mount, but is mechanically in a quite awful condition (bought very cheaply as "for parts" non-functional item, later repaired to usable condition at a local shop). Some days ago I found a paper about reptiles published in a Catalonian scientific journal where UV images are included (Arribas 2012). The author describes the Olympus OM 50mm f:3.5 macro as having good UV transmittance and the images seem to confirm this. This seemed interesting enough to take a risk, so I ordered one through eBay (still in transit) and will soon report here what I find out. The copy I ordered is of the early "silver nose" version with a serial number corresponding to single coated units. I am keeping my fingers crossed. Based on the list at this site, I also ordered an Olympus OM G.Zuiko 35mm f:2.8, also with silver nose and low serial number, which should hopefully also be an early production single coated unit.

 

I will upload images when I have suitable ones for this site. Meanwhile I give here some links to my albums at Flickr and the website I keep for my research at the University of Helsinki.

 

https://www.flickr.com/photos/115757516@N05/albums

http://blogs.helsinki.fi/senpep-blog/

 

Finally a plug and an invitation. I am the communications officer of a international scientific association called UV4Plants. It was formed just short of two years ago, and its focus is on Plant UV research from a broad perspective. One of our aims is to reach to the wider public, so there are no strict requisites for membership. One of the main activities in addition to organizing a conference and training events, is the publication of the UV4Plants Bulletin. This is an open access publication, with its ISSN. Every article is assigned a DOI and will be permanently archived for long-term access. There are no charges for publication for members, invited manuscripts, or smaller items, like book reviews, equipment reviews, letters or news items. Offered manuscripts from non members may incur in a small handling fee, that we are happy to wave upon request or if at least one author joins the association. The annual membership fee is 50/25 €. In the Bulletin we have no charges for colour images, neither hard limits on numbers of images or pages. We do not accept verbose articles, but long articles with enough substance have no penalty at all. As editor of the UV4Plants bulletin I invite all members of this site to explore who we are, what we do, and to join if you find what we do of interest. I know several members of our association are interested in UV photography. If you would like more information, please, feel free to send me a message at info@uv4plants.org or through this site. I hope including this paragraph does not break the rules of the ultraviolet photography site. The Bulletin is strictly non-profit and I do the typesetting and graphical design. The contents of the first two issues is more limited than the actual intended scope of the Bulletin, and we welcome articles on a broad range of subjects, please check the scope before deciding "this is not for me".

 

http://www.uv4plants.org/

http://uv4plants.org/publications/uv4plants-bulletin/

http://uv4plants.org/publications/uv4plants-bulletin-published-issues/

 

Best regards,

 

Pedro.

 

References:

 

Arribas, O. J. (2012) The Ultraviolet Photography of Nature: Techniques, Material and (especially) Lacertini results Butll. Soc. Cat. Herp., 20:72-114. http://www.lacerta.de/AS/Bibliografie/BIB_7000.pdf

[nfoto]

Welcome to UVP. I am confident you will find our little corner of cyberspace well worth visiting .... Will certainly look into the UV4Plants site in the near future.

 

If you had asked, members here would have warned you about the poor UV performance of the Kyoei 35/3.5 in Leica mount :(

[JCDowdy]

Welcome Pedro, nice to have another photobiologist!

 

I shall take a look at your association.

[Andrea B.]

Welcome to UVP Pedro. We look forward to your contributions and comments.

 

Your UV4Plants group sounds very interesting. Perhaps they would be interested in our UV botanical section?

 

I must say to any scientific group really interested in UV photography: please do try to get a UV-dedicated, chromatically corrected lens. It will make a huge difference in the quality of the images you record. I realize the cost is high for either the UV-Rayfact 105/4.5 or the Coastal Optics 60/4.0, but in my opinion the image quality is worth it - in addition to which you will have access to a very wide UV bandwidth not available with other non-UV lenses. This enables broader studies in the UV arena. With a UV-dedicated lens having quartz or fluoride elements (or a combo), you will not have to deal with chromatic blur or focus shift or other artifacts which may occur when using an 'ordinary' lens.

[aphalo]

Yes, in the long run we should get a real UV objective. I have not given up on this idea but at the moment our budget is very tight. I have one collaborator at another institute who has an UV-Nikkor, I will try to borrow it for a test.

Surely some members of UV4Plants will be interested in UVP site.

[Alex H]

Pedro, do not underestimate what can be done with the so-called "accidental" UV-capable lenses. All these discussions about "real" UV objectives somehow omit the fact that filters and cameras we use are also limiting factors. What good is it to use UV-Nikkor (comparing to for example Leitz Focotar-II or Kyoei lenses) if the camera does not record anything useful at 310nm, and the filter cuts at 320nm? The fact that they are superachromats? With live view camera focus shift is not longer an issue. Sharper? That is questionable. Native on F-mount bodies and CPU-chipped. Advantage only for Nikon users.

 

Andrea, what is "chromatic blur"?

[Andrea B.]

Don't forget, I also use Sony !!

And some labs use CCD cameras, not DSLRs or Mirrorless conversions.

 

Yes, that is a valid point about focus shift being moot when using Live View. But if the UV illumination is low, and it often is, we sometimes have to fall back on focusing prior to the addition of the UV-pass filter. So focus shift, or lack thereof, is still important.

 

There is a wide range of UV bandpass filters available for working between, say, 300 - 340 nm. I do not yet know of a definitive study which says nothing useful can be recorded at 310nm with DSLR or Mirrorless sensors. But any such reference would be most welcomed. None of us have really ever known whether we can shoot there or not.

 

As for sharpness, well, opinions differ --- as they should. I have not yet found any lens sharper than that Coastal Optics 60/4.0 although it is rather a pain in the neck to shoot with. And there is the whole ball of was about whether one is referring to edge acutance or to lines/mm resolution. I suppose we should have some kind of methodology in place that we can all use to judge sharpness. Shoot a test chart at X number of feet or meters? I can do that. Maybe I should order up one of those nice star charts.

 

Pedro, we have a lot of [Point :: Counterpoint] discussions here. It is how we all learn. :D

[aphalo]

Yes, indeed! Discussions and brainstorming are good. :) I agree, there are many different aspects in choosing an objective. For an M43 camera as I have, 105 mm is too long a focal length to use in a normal height copy stand and whole plants. A 60 mm objective would work. If my 35 mm Kyoei would be mechanically in a better condition it would be great together with my EM-1 and the adapter with helicoid I have. With the built-in electronic viewfinder in the Olympus EM-1, I have not had difficulties with focusing. Liveview on my tablet via wifi helps when the camera is in an uncomfortable position to use the viewfinder or the built-in screen. Or when indoors I can also use live view on my PC via USB for focusing. Optically and cosmetically my Kyoei is like new, but the front is quite wobbly. The seller told me that if I had not bought it he would had put it in the rubbish bin!

[Alex H]

Pedro, next time you are looking for UV-capable lens, I'd suggest you ask here first. I know some of us have accumulated too many lenses to be able to use them. At least I did.