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UltravioletPhotography

CCTV lens for UV?


msubees

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Anybody here has tried a CCTV lens? I thought I saw somewhere they might transmit UV, but googling could not find a link (it could be T lens I saw last time).

 

The main reason is they have some very wide lens (8.5, 12, 20, 25mm etc) and fast (F1.7, F1.2). they are cheap lens so they might not have coatings to remove UV if the sensor is protected by hot mirror inside.

 

Zach

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enricosavazzi

It is not impossible, but not likely either. Good lens coatings are now ubiquitous and not that expensive, so I don't think a company would make a good lens and then skimp on coatings. I would not recommend buying CCTV lenses at random as an efficient way to find a lens for UV photography, considering that quite good legacy 35 mm f/3.5 lenses for this use, with a little luck, can be found for $20-30. But if you have access to a broad range of CCTV lenses and have time to test them, it cannot hurt doing so.

 

Then there is the problem of small image circle and poor image resolution. CCTV lenses are designed for videocamera sensors much smaller and of much lower pixel count than our still cameras modified for UV photography.

 

There are a few models of quartz and fluoride/quartz lenses in C mounts and they probably work well in UVA to UVC (except for the small image circle), but they are far from cheap.

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Enrico,

 

Thanks for your insights. I was really trying to find a winder lens since the 35mm becomes 70mm on my panasonic G5.

 

I do not have access to any free TV lenses...have to get them by ebay.

 

Zach

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Zach,

 

Iggy has reported that the Wollensak Velostigmat 25mm F/1.5, an antique c-mount 16mm cine lens, has worked well in UV for him.

 

However, one would hardly call them cheap either.

 

John D

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@ Zach,

 

None of the "modern" CCTV lenses out there are UV-satisfactory, Zach.

 

Enrico is spot-on with what he stated.

 

I know. I've tested just about every single one that I can get my hands on. In all of the optical focal lengths, too. And not just the C-mounts, but also some of the less-common mounts, as well.

 

(Although, it should be noted that some of them do quite well in IR, though. No hot-spots or other anomalies. And that makes sense, if we remember that some of these CCTV lenses are being implemented in IR camera / night-vision security systems.)

 

And, Enrico is also correct in stating that they all (more or less) use UV-suppressive coatings, these days. It is not expensive at all for a company to procure and implement basic multi-coating batches in bulk, these days. In fact, the coating-application process is quite probably the cheapest part of the entire lens-assembly line process. ;)

 

(The glass and metal fabrication costs more).

 

So, save yourself the time (and $$$$), Zach. Believe me, I've blown more $$$$ on that same notion, than I'd like to admit. :P Use my own (wasted) money from that failed idea, to save your own $$$$.

 

(You're welcome. :) )

 

@ John,

 

Yes, the Wollensak Velostigmat 25mm F/1.5 (16mm cine lens) is a very good UV performer. But NOT because it was designed under the "CCTV" designation. Granted, it uses the same 'C-mount' as these "modern" offerings ... but ... the difference being, it was made for film and film movie-reel at the time. And, it was made at a time (late 40's, throughout the 1950's, and early 60's) when coatings were not that UV-suppressive (in most cases). But, more importantly, some of these older cine lenses implemented air-spaced elements (no cementing), and the optical formulas were also more simple, as well.

 

Zach, next time a Wollensak Velostigmat 25mm F/1.5 is spotted on 'Ebay' for a reasonable price, I will just let you know.

 

(I've already hoarded up 7 copies of my own. But, I'll probably sell most of them off, eventually.)

 

Right now, all I see is some crazy price-gouging going on on Ebay ... into the $300, and even $400 range. Seriously???

 

(A reasonable price would stay below the $200 line. $100 to $150 is fair, if it is in very good condition. Below $100 is not commonly found, but would be a steal, if there is no serious damage.)

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I also wanted to mention that there is more than one variation on the Wollensak Velostigmat 25mm F/1.5 cine lens.

 

The later versions (all chrome colored), particularly the 'Raptar' versions, tend to use more suppressive coatings, and therefore are not UV-capable like the earlier variant which I have referred to. If you spot a logo or stamp anywhere on the lens , marked with a small "w" inside of a large "C" (which means "coated Wollensak"), then this is a dead giveaway that this is NOT the one which I have found to be UV-satisfactory.

 

(In fact, this early Wollensak Velostigmat has no coatings at all! It is bare glass. But flare is still well-controlled, given the fact that the front element is deeply recessed inside the hood-like front barrel.)

 

The earlier variant has a dark copper-colored front hood component, in contrast to the remaining chrome body. And, it has the statements "WOLLENSAK 1 INCH f/1.5 CINE VELOSTIGMAT" stamped all around the perimeter of that front, dark copper-colored segment.

 

Also, it uses a 25mm thread. Thus, a 25mm to 52mm (or otherwise) step-up ring is mandatory for using filters on it.

 

Finally, given its relatively small image circle, it will only fully cover the sensor of the Micro-4/3 camera format (Panasonic / Olympus), or any crop sensors even smaller than that. But not so sure about most APS-C cameras (except perhaps Sony NEX / E-series mirrorless? I haven't tried yet), and DEFINITELY not for DSLR APS-C bodies or Full-Frame (unless you like that "porthole" look. Hah.)

 

(I also recommend that if you were to find one at a reasonable price, make sure to also buy a "C-mount macro ring set", in addition to a C-mount to Micro-4/3 adapter. This is important, because the lens doesn't focus very close. Thus, if you want to use it for floral UV photography, you will need a few macro rings between the lens mount and the camera adapter to focus closer and fill up the entire frame with the flower. Here is an example of the proper C-mount macro set: http://www.ebay.com/...=item56686200dc ).

 

An example, below, on what the proper variant looks like:

 

post-34-0-09848100-1408338836_thumb.png

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Confirm the above statements on CCTV lenses. They may be OK for their designated purpose, but in general turn in poor image quality used otherwise.

 

I was to elaborate on cine lenses when I first read this thread (yesterday), but now see Igor has done that already. I concur with his analysis, only adding that cine and video lenses (in particular vintage ones) are completely different animals even though mounts may be similar. Cine lenses were built to give very high resolution over a small image circle.

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I would surely like to see some of this thread about the Wollensak in its own post so that it would be more searchable.

Later I might attempt to split this thread and do that. Have other items to attend to this morning.

 

Given that we are not a forum, but more of a documentary site we need to try to not let threads wander too much as I'm sure you all understand. :)

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Yes, Andrea. You are correct, indeed.

 

However, keep in mind that since Zach's original thread topic was titled "CCTV Lens" (UV viability inquiry), and the Wollensak Velostigmat uses the same c-mount as more of the "modern" CCTV lenses on the market, then I feel that its inclusion in this thread (as per John's initially bringing it up) was a fair and proper inclusion.

 

Perhaps (and this is just my thought) ... maybe instead of "moving" or "splitting" the part of the thread with the Wollensak, it would be an even more useful move (for future searchers) to actually DUPLICATE the Wollensak part of the thread into its own separate thread (while retaining this original "CCTV" inquiry"). This would create a separate Wollensak Velostigmat discussion, on top of that.

 

(That way, both threads are relevant in their own right ... but you also don't end up clipping the Wollensak from the CCTV discussion, either.)

 

It's just that many photographer out there are grouping "CCTV", "Cine", and "C-mount" lenses under the same general topics, these days (whether technically correct or incorrect, notwithstanding), and thus, would be useful for future searchers to have more than one search result when checking the web database.

 

Just a thought. Thanks, Andrea!

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Igor and others, thanks for the useful information and discussion. Maybe I should not venture into the C-mount lens world... too much complications for me. :D

 

Zach

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Hahah. No one is telling you not to "venture" anywhere, for that matter. By all means, go out and test - test - test. I don't think that any person should be the "final authority" on any matter. (There is an ongoing danger in harboring the indoctrination and notions of infallibility / irrefutability, within the sciences).

 

I think the very reason we are all here, is because we have plunked down (and in some cases, continue to plunk down) our own, hard-earned pennies at experimentation, while always at the mercy and risk of wasting that self-funding with nothing to show for it.

 

(Scientific discovery has never been a "free" endeavor. There have always been costs and sacrifices. Some much higher than others.)

 

In either case, though, I am not saying that there may not be some exceptions out there. Indeed, the world of "lens testing" is nearly limitless, because so many variants / models / re-designs litter the market. Especially on the "vintage" or "legacy lens" scene.

 

So, if you have the cash for self-testing (and the stomach for potentially losing cash on non-fruitful results), by all means ... don't let any of us stop you from going your own way. There will always be something new to discover, which has been otherwise unknown.

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....and you can always resell a lens after you have tested it and decided it is not suitable for your particular purpose. No guarantee that you would get back the same amount you paid for it, but you would get something. :D

 

Igor I'm not moving anything. Too much trouble! :D I'm still working on the summer's backlog of flower docs.

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Hi Zach,

 

I'm afraid this may not the answer you are expecting, but Ricoh/Pentax makes a couple of c-mount lenses dedicated for UV under Cosmicar brand, namely B2528-UV (25mm/f2.8) and B7838-UV (78mm/f3.8).

 

They are quit expensive (soul be over 1,000 USD and 3,000 US respectively), and their image quality is unknown. Both lenses are designed for the 1" sensor.

 

Hope this would be of any help.

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....and you can always resell a lens after you have tested it and decided it is not suitable for your particular purpose. No guarantee that you would get back the same amount you paid for it, but you would get something. :D

 

That's for sure.

 

Unfortunately, repeatedly buying and selling also creates a messy tax consequence, as well. (Ex: Selling through venues such as Ebay or Amazon, for instance, generates a "miscellaneous income" report sent to the IRS). And the seller is liable to report the fiscal difference between buying / selling, whether it's a profit or a loss. For every single item, I might say.

 

This is an expense (a loss in time), which cannot be recouped. Time is expensive too, after all.

 

Igor I'm not moving anything. Too much trouble! :D I'm still working on the summer's backlog of flower docs.

 

Heheh. I never held you to it, Andrea. ;)

 

I'm just saying: When or even if you ever do, consider not creating "orphans" out of certain comment segments when the topic matter may actually be relevant to more than one thread, including the native thread.

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Ricoh/Pentax makes a couple of c-mount lenses dedicated for UV under Cosmicar brand, namely B2528-UV (25mm/f2.8) and B7838-UV (78mm/f3.8).

 

They are quit expensive (soul be over 1,000 USD and 3,000 US respectively), and their image quality is unknown. Both lenses are designed for the 1" sensor.

 

That's definitely another 25mm option. An interesting one, certainly.

 

However ... seeing as the 25mm Wollensak Velostigmat F/1.5 already churns out quite satisfying UV results (I will hopefully make the time soon to make an official post of this lens and its performance), I don't see it a logical choice to spend thousands for something when the alternative only costs hundreds. (Unless someone LIKES burning through money just for the heck of it :D ).

 

(And yes, the WV F/1.5 is quite sharp in resolution, too! Well, when it's stopped down, of course. Not so, when wide open at F/1.5. But then, that's the case with many other lenses, too. Even the more expensive ones.)

 

I do, however, want to mention that the maximum aperture of F/1.5 on the WV is quite handy, for doing handheld UV exposures, without a tripod! (when optimal sharpness is not a priority). This is not something UV shooters can brag about when using most other lenses, without ramping ISO up to the stratosphere.

 

What other UV-satisfactory lenses do we know about, that have such a bright maximum aperture? I don't know of any, myself. But, perhaps some of the more experienced among you may know?

 

(I've gotten some decent results doing handheld / non-tripod UV shots at F/1.5. Maybe not "documentary quality" at maximum photo size / enlargement, but for general-purpose presentations and web-publishing photo sizes, this is quite an advantage as it can bypass some extra set-up time. Increasingly more useful, when outdoor UV shots are otherwise not as cooperative, such as on windy days or subjects with substantial movement.)

 

Right now, I am in the middle of testing how a bright-aperture UV-satisfactory lens can be potentially invaluable for photographing UV patterns on insects that are never standing still for too long, thus requiring faster shutter speeds.

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Speaking of which, here is a photo taken of Ranunculus acris - in UV - using the WV F/1.5 at wide-open aperture (or close to it, I think. I cannot remember for certain).

 

Granted, this WV F/1.5 produces the signature "swirly bokeh" of the OOF (out of focus) objects around the edges of the frame, at wide-open. An optical phenomenon that is common to vintage cine lenses from the 40's and 50's.

 

But, for all intents and purposes, the results are still good enough for a general or informal examination of certain subjects ... IF one is stuck outdoors or in a situation without a tripod, or in a situation where a faster shutter would be more important than corner / edge sharpness and optimal resolution.

 

My point is: I used a shutter of 1/15 in this photo. And all I had to do was steady my hands. :D

 

(And I didn't have to compromise with high-grain ISO, either.)

 

post-34-0-91410000-1408495978_thumb.png

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That 25 mm lens sounds tempting ...

 

If I understand correctly, it is made from quartz glass elements only and is not chromatically corrected.

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That will be a lesser issue for narrow-band imaging. I'm primarily concerned with having high enough UV transmission available for high-magnification work. A reversed cine lens should perform well.
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Bjørn,

 

Universe Kogaku America has a selection of quartz lenses of which you are most likely aware.

I have the UV2528B and it appears to be the exact same lens as the Cosmicar B2528-UV.

My UKA UV2528B covers my µ4/3 sensor without apparent vignetting.

Being quartz only it has a lot of CA but with UV-LEDs there is not much chroma to aberate! :D

 

The one I would like to examine is the Pentax H2520-UVM which is a quartz fluorite lens, but I do not think it is currently in production.

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The one I would like to examine is the Pentax H2520-UVM which is a quartz fluorite lens, but I do not think it is currently in production.

 

Wow, John. That one has an F/2 aperture. NOW we're talking! That's got MY attention, compared to many of the other offerings which - aside from being optimized in other areas - nevertheless have typically average wide-aperture designs ... as I would normally respond with "meh." :D

 

But, THIS one, looks tempting for me, indeed. Regardless of cost.

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Iggy,

 

I don't know if I would be so eager to throw down a lot of cash should you find one.

 

First, it is made for a 1/2" sensor so it may not fill a µ4/3 frame unless on extension tube.

However, this document seems to imply it might (29,5mm Ø), see page 3.

 

Second, it is made for a 2 mega pixel system so it may not have very high resolution.

 

I just said I would like to examine one.......

 

Here is some more info on it.

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Universe Kogaku...

I see they offer a 50/3.5. Too funny!! We have handfuls of UV-capable 50/3.5s by now, most of us. :D

 

I do not like these uncorrected quartz lenses. But whatever. There are a few manufacturers out there making these lenses, mostly it seems for CCTV, but not always. Sodern Cerco, Universe Kogaku ==> I've never listed them in the Sticky for various reasons. Perhaps I should at least reference them ??? If so, we would need to reference the pros & cons. Feedback welcomed on this listing topic.

 

Just now I put it onto my Shooting List to take my Quartz Takumar out for a shoot to see what I can get and what problems arise.

 

Today I'm going out for some UV landscape comparisons with my F-mount set. Not looking to shoot art or documenation. Just going to practice lens testing and try to figure out what is useful.

 

Also going to look for any stray wildflowers that have somehow escaped my UV doc efforts over the years. :D ;) :D

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Universe Kogaku...

I see they offer a 50/3.5. Too funny!! We have handfuls of UV-capable 50/3.5s by now, most of us. :D

 

I do not like these uncorrected quartz lenses. But whatever. There are a few manufacturers out there making these lenses, mostly it seems for CCTV, but not always. Sodern Cerco, Universe Kogaku ==> I've never listed them in the Sticky for various reasons. Perhaps I should at least reference them ??? If so, we would need to reference the pros & cons. Feedback welcomed on this listing topic.

 

Yep, I have both the UKA 25mm and 50mm and recently a Cerco 100mm F/2.8 2078 too.

When I have time I will write up something on them.

 

PS:

DaveO used a UKA quartz 105mm until he upgraded to the Rayfact 105.

He made a number of formal botanical postings with that UKA lens as well as some of his "trials and tribulations" with it.

I originally had the UKA quartz 78mm but replaced it with the 50mm as the 78mm had to narrow a FOV on my µ4/3.

My Coreopsis tinctoria was done with the UKA 50mm, but I am obviously not a skimmed as DaveO.

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