The Enna München Ennalyt clones

[igoriginal]

BTW I noticed there is what appears to be a 135mm version of this lens:

 

http://m42lens.com/m...-135mm-f-3-5-22

 

It looks like a stretched version of the 35mm lens with the same four screw M42 mount (and I'm guessing same underlying T mount). Anyone know anything about this lens and its UV potential?

 

Yes, I am aware of the 135mm F/3.5 version of this lens (of the same release series, in the bakelite build).

 

I haven't gotten around to testing one of these, yet.

 

However, as far as I know, its optical formula is 5 elements / 5 groups. So, it may be UV viable, indeed. Although, having an extra element (compared to the 4 elements /4 groups optical formula of the 35mm F/3.5 design), there might be a notable reduction in UV transmission. Might being the key word. (One extra piece of glass may or may not make a big difference. It depends.)

 

I would confidently wager a bet that the 135's UV transmission will definitely not exceed that of the 35's ability, though. Perhaps come close to matching it (if that), but definitely not exceed it.

[lost cat]

Yes, I am aware of the 135mm F/3.5 version of this lens (of the same release series, in the bakelite build).

 

I haven't gotten around to testing one of these, yet.

 

However, as far as I know, its optical formula is 5 elements / 5 groups. So, it may be UV viable, indeed. However, having an extra element (compared to the 4 elements /4 groups optical formula of the 35mm F/3.5 design), there might be a slight reduction in UV transmission. Might being the key word. I would confidently wager a bet that the 135's UV transmission will definitely not exceed that of the 35's ability, though. Perhaps come close to matching it (if that), but definitely not exceed it.

 

Revisiting the lens sticky I see the Enna 135/3.5 Ennalyt there. This lens is a rebaged Tele-Ennalyt according to M42lens. So its probably good for UV.

[igoriginal]

I do

Revisiting the lens sticky I see the Enna 135/3.5 Ennalyt there. This lens is a rebaged Tele-Ennalyt according to M42lens. So its probably good for UV.

 

Be aware, however, that there is also another series of Enna Ennalyt 135/3.5 (and 35/3.5), in an all-metal build (rather than the bakelite series build). These metal series also can be identified by their "Zebra" cosmetics. (Alternating black paint and unpainted polished metal). Unfortunately, the UV Lens Sticky does not indicate which series it is. (And this is no blame on Andrea, since she probably wasn't aware of, nor even given the proper information, to supply the distinction between the two series).

 

Some on-line reviews that I have read have claimed that the all-metal series does not perform as well as the bakelite series, when it comes to image quality / resolution and corner sharpness, ironically. The reason this is ironic, is because the bakelite series was fabricated at a time of material shortages (and could even be considered as the "budget" version), compared to the more expensively-fabricated and higher price-point all-metal series.

 

Now, until someone actually does a back-to-back comparison transmission test ("Ennalyt: Battle of the Bakelite versus the Metal", as a suitable title, perhaps? Haha) ... then it's anyone's guess which of the two series do better with UV transmission. So, 'till then, it is unclear which series the UV Lens Sticky is referring to.

 

What we do know, for now, is this: At least one of the Ennalyt 35mm F/3.5 series (along with its clones / re-branders / re-sellers) is an exceptional UV performer, reaching down to as low as 320nm, according to some accounts and transmission tests.

 

Having personal ownership and use of many copies of the 35mm F/3.5 bakelites for myself ... I would assume that it is the bakelite series that transmit this deeply. (But it could also turn out that both series transmit deeply ... irrespective of their image quality / corner sharpness differences, which is a different area of contention, altogether.)

[igoriginal]

Here is the "metal zebra" that I was referring to:

 

http://m42lens.com/m42-lens-database/803-enna-munchen-tele-ennalyt-135mm-f-3-5-22-zebra

 

Hey, wait. That would be a great heavy-metal rock band name. Metal Zebra. B) B) B)

[lost cat]

I do

 

Be aware, however, that there is also another series of Enna Ennalyt 135/3.5 (and 35/3.5), in an all-metal build (rather than the bakelite series build). These metal series also can be identified by their "Zebra" cosmetics. (Alternating black paint and unpainted polished metal). Unfortunately, the UV Lens Sticky does not indicate which series it is. (And this is no blame on Andrea, since she probably wasn't aware of, nor even given the proper information, to supply the distinction between the two series).

 

Some on-line reviews that I have read have claimed that the all-metal series does not perform as well as the bakelite series, when it comes to image quality / resolution and corner sharpness, ironically. The reason this is ironic, is because the bakelite series was fabricated at a time of material shortages (and could even be considered as the "budget" version), compared to the more expensively-fabricated and higher price-point all-metal series.

 

Now, until someone actually does a back-to-back comparison transmission test ("Ennalyt: Battle of the Bakelite versus the Metal", as a suitable title, perhaps? Haha) ... then it's anyone's guess which of the two series do better with UV transmission. So, 'till then, it is unclear which series the UV Lens Sticky is referring to.

 

What we do know, for now, is this: At least one of the Ennalyt 35mm F/3.5 series (along with its clones / re-branders / re-sellers) is an exceptional UV performer, reaching down to as low as 320nm, according to some accounts and transmission tests.

 

Having personal ownership and use of many copies of the 35mm F/3.5 bakelites for myself ... I would assume that it is the bakelite series that transmit this deeply. (But it could also turn out that both series transmit deeply ... irrespective of their image quality / corner sharpness differences, which is a different area of contention, altogether.)

 

Its also possible the metal and bakelite lenses are optically identical with the changes limited to the lens body, focusing and aperture hardware and perhaps better coatings rather than reinvent the *optical* wheel. Perhaps the bakelite was problematic for such a large lens.

[igoriginal]

It's also possible the metal and bakelite lenses are optically identical with the changes limited to the lens body, focusing and aperture hardware and perhaps better coatings rather than reinvent the *optical* wheel.

 

That's a good possibility, yes. And that has crossed my mind, too. But then, if some reviews note differences in image quality / corner sharpness between the bakelite and metal series, then one has to wonder if there were some other possible changes, too. (Internally). It could be possible that cemented elements were introduced. Or that an extra element was added, even to the 35mm F/3.5 optical formula. Not to mention, the sourcing and smelting of the glass, in itself, could have involved changes to the ratio of different mineral properties. Or of varying refractive indices, and other potential variables. There could be any number of unaccounted-for variables involved. Sometimes, element positioning (the precise space between each element) is changed. Sometimes, even the geometric curvature of an element is somewhat modified. (Even a fraction of a millimeter of difference can change optical behavior / performance.)

 

But, now, I would be venturing down a path I am not an expert in.

 

Regardless ... ultimately, it all comes down to getting the lens, and testing it for oneself, when all is said and done. Right? ;)

[igoriginal]

Perhaps the bakelite was problematic for such a large lens.

 

Although ... whether this design was problematic or not, was irrelevant at the time that this series was released ... because those were the limited materials that the manufacturers were forced to work with, whether they liked it or not.

 

Personally, I happen to like the bakelite build (even for all its inherent fickleness and quirks), especially when it plays to my advantage. (Ex: Allowing an already lightweight mirrorless-camera body to remain light, even when bundled with this lens.) Not to mention, it is soooooo easy to open up, clean out, and service.

 

(And must we be reminded that its close-focusing ability beats the pants out of many other 35mm F/3.5's from the same era.)

 

True, that it's not a lens for everyone, and everything. But, a curious oddity it remains. And it does have a cult following.

[lost cat]

That's a good possibility, yes. And that has crossed my mind, too. But then, if some reviews note differences in image quality / corner sharpness between the bakelite and metal series, then one has to wonder if there were some other possible changes, too. (Internally). It could be possible that cemented elements were introduced. Or that an extra element was added, even to the 35mm F/3.5 optical formula. Not to mention, the sourcing and smelting of the glass, in itself, could have involved changes to the ratio of different mineral properties. Or of varying refractive indices, and other potential variables. There could be any number of unaccounted-for variables involved. Sometimes, element positioning (the precise space between each element) is changed. Sometimes, even the geometric curvature of an element is somewhat modified. (Even a fraction of a millimeter of difference can change optical behavior / performance.)

 

But, now, I would be venturing down a path I am not an expert in.

 

Regardless ... ultimately, it all comes down to getting the lens, and testing it for oneself, when all is said and done. Right? ;)

 

Well the Enna version of this lens is listed in the sticky. If the sticky is referencing the bakelite version then its good for UV. If its referencing the metal version then for the aforementioned reasons the bakelite variety should be even better.

 

But as you say nothing beats hands on testing.

[lost cat]

M42lens have 135mm clones for both Prost and Universar. The Prost mentions an underlying T mount:

 

Universar:

http://m42lens.com/m...m-f-3-5-22-enna

 

Prost:

http://m42lens.com/m...m-f-3-5-22-enna

 

There is also a 300mm Revue lens that again looks like an even more stretched version of the 35mm. This lens has 5 elements in 4 groups so maybe its not so UV compatible but it may be worth a look.

http://m42lens.com/m...m-f-5-6-22-enna

[igoriginal]

M42lens have 135mm clones for both Prost and Universar. The Prost mentions an underlying T mount:

 

Universar:

http://m42lens.com/m...m-f-3-5-22-enna

 

Prost:

http://m42lens.com/m...m-f-3-5-22-enna

 

There is also a 300mm Revue lens that again looks like an even more stretched version of the 35mm. This lens has 5 elements in 4 groups so maybe its not so UV compatible but it may be worth a look.

http://m42lens.com/m...m-f-5-6-22-enna

 

Very interesting.

 

Yes, looks like the post-WWII Allied-occupied Germans (in this case, under temporary U.S. occupation with regards to the Bavarian city of Munich / München) went nuts with that Bakelite lens build, didn't they? :D

 

And, indeed, when I see that a lens's element count is higher than the group count, I begin to suspect some form of cementing at work. However, this doesn't necessarily mean that the lens cement will be UV-obstructive. (Some types of lens cement is fairly UV-transparent, while other types of lens cement cuts off a substantial amount of UV.)

 

Thus, like I said, until one actually gets a hold of the lens, and directly tests it for UV transmission, it's all up in the air.

 

But, yeah. They really went wild with that Bakelite plastic, didn't they? And I imagine that they were FORCED to, for quite a while, due to the post-war economic sanctions and metal shortages at the time.

[igoriginal]

Speaking of which, were you aware that the U.S. Mint came THIS close to making the decision to start mass-minting one-cent U.S pennies from Bakelite, back in 1943? (When the increasing demand for certain metals for military applications, especially copper, led to an impending shortage for civilian use.) I kid you not.

 

Ultimately, though, they decided against it, and instead opted for zinc-coated steel pennies. (Those "white" pennies, minted in 1943, which have increasingly become a numismatic collective piece.)

 

But ... imagine, had the decision been finalized? Wow.

 

(NOTE: There were ongoing talks by the U.S. Treasury, that had the war gone on much longer, then the switch to Bakelite coinage would eventually become inevitable, anyway.)

 

Maybe in some alternate universe, on a mirrored Earth not too dissimilar to our own, this may have happened? :D

 

ANOTHER interesting factoid: The war-time steel cent is the only regular-issue United States coin that can be picked up with a magnet.

[Andy Perrin]

Ultimately, though, they decided against it, and instead opted for zinc-coated steel pennies. (Those "white" pennies, minted in 1943, which have increasingly become a numismatic collective piece.)...

 

ANOTHER interesting factoid: The war-time steel cent is the only regular-issue United States coin that can be picked up with a magnet.

I was not aware that they were becoming collector's pieces! I have dozens of them! Well that is nice to know.

[igoriginal]

I was not aware that they were becoming collector's pieces! I have dozens of them! Well that is nice to know.

 

In recent history (the past few decades), the U.S. Mint's mission has been to gather them all up, and destroy all of them ... believe it or not! (Melt them down, for scrap.)

 

This is because of the fact that since these coins can be magnetized and also respond to magnetism, they can potentially mess with the automated processes of various coin-dispensing / coin-slot apparatus ... such as vending machines, self check-out grocery kiosks, and other such devices.

 

Hence, these pieces are going to become harder and harder to procure as time goes by ... because the U.S. Mint has sought their destruction in the past, and will probably continue to do so. Thus, yes, HOLD ON to them.

[lost cat]

Very interesting.

 

Yes, looks like the post-WWII Allied-occupied Germans (in this case, under temporary U.S. occupation with regards to the Bavarian city of Munich / München) went nuts with that Bakelite lens build, didn't they? :D

 

And, indeed, when I see that a lens's element count is higher than the group count, I begin to suspect some form of cementing at work. However, this doesn't necessarily mean that the lens cement will be UV-obstructive. (Some types of lens cement is fairly UV-transparent, while other types of lens cement cuts off a substantial amount of UV.)

 

Thus, like I said, until one actually gets a hold of the lens, and directly tests it for UV transmission, it's all up in the air.

 

But, yeah. They really went wild with that Bakelite plastic, didn't they? And I imagine that they were FORCED to, for quite a while, due to the post-war economic sanctions and metal shortages at the time.

 

If it works it works. Bakelite is very light, doesn't rust, doesn't get too hot in sunlight (no more than metal anyway) and has been durable enough for many consumer products like telephone handsets which tend to take a lot of abuse. There are much better plastics now but for its day it wasn't too bad.

 

I don't think making the threaded mounts out of the stuff was such a great idea (apparently neither did Revue since one of my lenses has a metal M42 adapter) but stripped bakelite threads are probably fixable with epoxy.

[igoriginal]

If it works it works. Bakelite is very light, doesn't rust, doesn't get too hot in sunlight (no more than metal anyway) and has been durable enough for many consumer products like telephone handsets which tend to take a lot of abuse. There are much better plastics now but for its day it wasn't too bad.

 

I don't think making the threaded mounts out of the stuff was such a great idea (apparently neither did Revue since one of my lenses has a metal M42 adapter) but stripped bakelite threads are probably fixable with epoxy.

 

Actually, Bakelite is still used even today, in certain applications where its unique characteristics are preferable, over other types plastics.

 

So, I wouldn't say that today's plastics are necessarily "better" in all applications. Just different.

 

For instance, compared to some other types of plastics, Bakelite is harder and less pliable, and thus better retains its shape (given that it's less flexible and rather more brittle, and hence less prone to warping over time). Whereas, many other plastics - while certainly more pliable and flexible - are also more prone to warping over time, especially if exposed to sunlight / heat for extended periods. Bakelite will not do this (it will not warp so easily, like many other plastics tend to.) Additionally, Bakelite exhibits higher stability against acoustics / resonance, so it is still widely used where dampening vibration within certain industrial devices is required, while keeping weight down. (Some bullet-proof body-armor has Bakelite resonance-dampening linings, to better absorb and distribute the energy from a projectile! And it's even used for the hilts of some special-ops lightweight guns, too, while improving their ability to evade metal detectors.) Additionally, many game pieces are also still being made from Bakelite (dice, chess pieces, dominoes, budget billiard balls, etc.), since they muffle sound better when impacted. And, having a higher heat tolerance, it is also used in some automotive parts (such as lighter-weight bearings, brake pads, and drums.) Its biggest growing demand, is within aerospace engineering, for novel new approaches to lightweight heat shielding / acoustics dampening.

 

If I am not mistaken, arcade machines and casino machines still use some Bakelite parts as accents and panels ... because of the ability to handle abuse, while making it easier for them to be moved around and relocated.

 

So, one has to better define within proper context, what is a "better" plastic ... because each plastic has its own inherent strengths and weaknesses.

 

Having said that, yes, I am sure that stripped threading on a Bakelite-based lens mount can be repaired, without too much trouble. Probably with less trouble than repairing the stripped threading on a metal mount, in some cases.

[igoriginal]

Some examples of recent aerospace corporate acquisitions, with respect to Bakelite-molding technologies:

 

http://www.plasticsnews.com/article/20140424/NEWS/140429924/sumitomo-bakelite-buying-injection-molder-vaupell-holdings

[Andrea B.]

Igor that is soooo off topic. Aerospace Corporate Acquisitions? Really? And for the Bakelite Lecture you could just plop a link to Wikipedia in there.

[igoriginal]

You're right, Andrea. No more on that. :)

 

I suppose this is what happens, when you have an oddity such as an all-Bakelike composed UV-capable lens become a topic of discussion.

[Andrea B.]

I think I should probably open up a thread for Lens Sticky updates now that I'm getting the file into better editing shape.

 

We could add this bakelite versus non-bakelite info about the preceding lens.

 

I add to the Lens Sticky whatever we are sent or whatever we find in the posts, so I'm sure some nuances are missed.

 

What I wish I had is actual transmission measurements made with dual-beam spectrophotometer + monochromator + integrating sphere + light source.

Although really it probably is not all that important as most of them shoot well enough between 365-400 nm.

And the few shots we have here below that don't show much of anything different.

[igoriginal]

I think I should probably open up a thread for Lens Sticky updates now that I'm getting the file into better editing shape.

 

We could add this bakelite versus non-bakelite info about the preceding lens.

 

I add to the Lens Sticky whatever we are sent or whatever we find in the posts, so I'm sure some nuances are missed.

 

What I wish I had is actual transmission measurements made with dual-beam spectrophotometer + monochromator + integrating sphere + light source.

Although really it probably is not all that important as most of them shoot well enough between 365-400 nm.

And the few shots we have here below that don't show much of anything different.

 

What I myself am going to be doing, in the next coming weeks, is finally get around to officially adding transmission data to all of my UV-discovered lenses, in a similar fashion as Steve Smeed has done with his narrowband filter array test.

 

I've purchased and had my own narrowband filters, for quite a while now (several years, now). But I've been too lazy to include such data along with all of my lens tests and reports. However, I am finally on it, and have come up with a more streamlined approach idea: To take a 72mm screw-in metal lens cap, drill mounting holes for each of the narrow-band filters that overlap the UV-A spectrum, and permanently seal and position these mounted filters along the edges of the screw-in lens cap in the fashion of a "clock" or "speed gauge." Meaning, for each 10nm bandwidth, there will be a "clock" / "speedometer" position on the testing cap. This will allow me to snap a full UV-A bandwidth transmission test all at one time, for any lens being tested ... thus maintaining lighting consistency across the entire UV-A spectral bandwidth ... while providing a neat way to read the results.

 

(Having each of the filters equidistant from a central point, by mounting them along the radius of a circle, will insure more consistent illumination ... as opposed to trying to photograph a long line or strip, which may elicit somewhat uneven angular directions of light. Well, at least in theory, anyway. But I think it's worth exploring, nonetheless.)

 

In additional, using a metal screw-in lens cap for mounting my "clockwork"-arranged narrowband filters will eliminate all potential light leaks. It also makes the test more portable, and I like the idea of a circular-arranged test, instead a long strip. Just like a "speedometer" on a car dash. I guess that will be my own unique calling card for such a test. ;)

 

Finally, the reason for me wanting to use such a large-diameter (72mm screw) lens cap, is that it's better to start with a larger-fitting testing template, just in case it can be compatible with virtually any lens. Whereas, any lenses with smaller-diameter threading can always be adapted with step-up rings on the 72mm cap-mounted test.

 

NOTE: I give full credit to Steve Smeed for coming up with the idea of using narrow-band filter arrays for this "poor man's spectrometer" idea. It's just that I am running on with my own "spin" on this idea. But, I just wanted to give credit where credit is due, since he is the original author of such an idea, and the inspiration for me following in those footsteps.

[lost cat]

I think I should probably open up a thread for Lens Sticky updates now that I'm getting the file into better editing shape.

 

We could add this bakelite versus non-bakelite info about the preceding lens.

 

I add to the Lens Sticky whatever we are sent or whatever we find in the posts, so I'm sure some nuances are missed.

 

What I wish I had is actual transmission measurements made with dual-beam spectrophotometer + monochromator + integrating sphere + light source.

Although really it probably is not all that important as most of them shoot well enough between 365-400 nm.

And the few shots we have here below that don't show much of anything different.

 

I agree, I feel a lot more confident in spectrophotometer data than bandpass filter array tests. Especially for filter data.

 

Klaus posts a fair amount of spectrophotometer data. Does he have a backlog to tap into?

[igoriginal]

I agree, I feel a lot more confident in spectrophotometer data than bandpass filter array tests. Especially for filter data.

 

Klaus posts a fair amount of spectrophotometer data. Does he have a backlog to tap into?

 

Spectrometer-device data is certainly the gold standard, I agree. But ... not everyone has access to it. And not every individual who posts actual transmission graphs is willing to be completely forthcoming with the SPECIFIC series / model of lens, for each test. (Just calling the lens by name, and focal length / aperture specs, doesn't necessarily refer to the correct model / series.) Not to mention, the immense value of listing serial number ranges, for each lens being tested, given that even the same exact series of lenses can somethings go through subtle production changes, e.i. - changes in the coatings used.

 

Secondly, narrow-bandpass filter array testing of UV-A transmission is actually fairly reliable. Steve Smeed has successfully demonstrated this, over and over again. My own (though limited tests) support his own findings. Again, not the gold standard, I agree. But, still a much better route than merely blind guesswork.

 

Thus, I think the more reasonable approach is to employ an overlap of transmission-graph data (when available) and narrow-bandpass filter array testing, in order to form a more complete picture, as well as fill in for missing gaps in the current information. So, in my opinion, the Lens Sticky should use the logic of "best available data", whatever that happens to be. IF and WHEN additional data supersedes the former data ... then of course, it should replace it. But that doesn't mean that more accessible testing should be rejected, in the meantime. I think it should be a top-down hierarchy approach to data-acquisition ... which is what the very foundation of the Scientific Method is founded on. (Start with the best available data. If that's not available, then use the next-best approach, for the time being. And so on, and so forth.)

 

Anyway, my own goals is to include lens serial numbers, lens series external cosmetics, etc., and other additional identification to better differentiate between lenses that could otherwise be confused with one another.

 

UPDATE: I haven't seen Klaus include serial numbers, and other physical identification attributes (cosmetics, materials of the lens build), attached to his tests. So, just how far can one go, with transmission data, if it remains uncertain which specific lens was used for the test? (Note that this is no harsh criticism of Dr. Schmitt's work. I am a staunch admirer of his ongoing work. Still, I am respectfully pointing out areas that are lacking, and could be improved upon.)

 

Ultimately, of course, actual photos of the lens specimens would be the epitome of identification.

 

Regardless ... narrow-bandpass filter array testing is valuable and viable, within its stated limitations. It may not scream "high-grade institutional" ... but, it gets the job done, and quite well.

[colinbm]

That will be good to do Igor, but if you want to give full credit to Steve, the full arrangement has always been known as a 'Steven Smeed Sparticle Filter Array'.

I have made one too at this link.... http://www.ultravioletphotography.com/content/index.php/topic/1282-panasonic-lumix-dmc-g3-camera/page__view__findpost__p__7848

Col

[Andrea B.]

I agree, I feel a lot more confident in spectrophotometer data than bandpass filter array tests. Especially for filter data.

 

JIm, I agree, FWIW. And so do most of us here.

 

But I will say that Sparticle filter board testing serves as very nice informal test so we can get an indication of the general UV-capability of a lens. We are all aware of the drawbacks of filter board testing -- lack of both precision and accuracy -- but enjoy seeing the tests anyway because we do not have access to scientific testing equipment. In short, I enjoy Steve's work and welcome it here.

 

And then there is this:

There seems to be a significant amount of disagreement about just how rigorous spetrophotometer lens transmission testing should be and actually is for some of the published results found across the web. I myself stand on the side of rigor -- but -- I do not reject out-of-hand the various less rigorous spectrophotometer tests because, again, they do serve as an indicator the general UV-capability of a particular lens.

 

*******

 

What Klaus has is on his blogsite but I cannot reproduce his work here That's ok, given that they are accessible there and I have made some links in the Sticky to some of them with Klaus' permission.

 

*******

 

Igor, get your lens transmissions properly measured is my suggestion. Else it is just more informality.

 

*******

 

There is a lot of eagerness to perform these informal depth tests of the UV transmission of a lens. Fine. But, there are other considerations which are very important to good UV photography just as they would be in Visible photography: propensity to flare, the various types of aberrations, fall-off, fine contrast, sharpness, etc. Some attention should be paid to that. It is simply not all about whether a lens can reach 340nm or not.

 

I've had all kinds of lenses out there in the field. When push comes to shove, it is the UV-Nikkor I grab because I know it won't fail me on any count. I wonder if Bjørn thinks the same? Although he would probably say that he grabs the C060. :D

[lost cat]

I agree, I feel a lot more confident in spectrophotometer data than bandpass filter array tests. Especially for filter data.

 

JIm, I agree, FWIW. And so do most of us here.

 

But I will say that Sparticle filter board testing serves as very nice informal test so we can get an indication of the general UV-capability of a lens. We are all aware of the drawbacks of filter board testing -- lack of both precision and accuracy -- but enjoy seeing the tests anyway because we do not have access to scientific testing equipment. In short, I enjoy Steve's work and welcome it here.

 

I also greatly appreciate Steve's contributions here. The Sparticle filter board test is a great "first approximation" test to measure lenses UV performance. Sure its not as rigorous as a "gold standard" spectrometer but the filter board has the advantages of cost, east of setup, and doesn't take up half the spare bedroom closet like a "gold standard" spectrometer rig would.

 

There is a lot of eagerness to perform these informal depth tests of the UV transmission of a lens. Fine. But, there are other considerations which are very important to good UV photography just as they would be in Visible photography: propensity to flare, the various types of aberrations, fall-off, fine contrast, sharpness, etc. Some attention should be paid to that. It is simply not all about whether a lens can reach 340nm or not.

 

Not all about, just mostly about ;).

 

I've had all kinds of lenses out there in the field. When push comes to shove, it is the UV-Nikkor I grab because I know it won't fail me on any count. I wonder if Bjørn thinks the same? Although he would probably say that he grabs the C060. :D

 

Unfortunately the prices on those make a "gold standard" spectrophotometer rig look downright reasonable :(