Canon EF 70-200mm Telephoto Zoom Lens for UV Photography

[The Skin Doc]

Can a Canon EF 70-200mm f/2.8L IS II USM AutoFocus Telephoto Zoom Lens be used for Ultraviolet Photography if a UV Bandpass Filter is used? Is there anti-UV coating applied on this lens that would prevent it from being used in UV photography even if using a UV Bandpass Filter? If it can be used, what filters do you suggest for indoor and outdoor use?

 

[bobfriedman]

nope...

[Cadmium]

You put the lime in the coconut, you drink 'em both up!

 

TSD, I think you mean "UV bandpass", instead of 'bypass'.

No, that lens will not transmit UV.

Why would you need to use a telephoto for shooting skin?

 

I don't actually know how dangerous UV-A is for skin, your the doctor, not me, but UV-A is dangerous for eyes, and therefore any time you are shooting with a UV enabled flash or other UV light,

you should wear eye protection and anyone else present, such as your subjects. Possibly, just closing their eyes is enough, but again, that is your field, not mine.

 

I don't know if you are wanting to do UV-only photos or UV Induced Visual Fluorescence (UVIVF).

I have heard of some skin doctors examining skin with 365-UV ('Black Light'), to examine the fluorescence from the skin...

UV-only, and Fluorescence photography are two completely different things.

Actually, you can do fluorescence photography with the zoom lens, but that is a whole other subject.

 

If you are wanting to do UV-only photos (320nm-400nm), then you will need a lens that is friendly for UV, one that transmits UV-A as deep as possible.

You could get one of several scientific lenses specially made for UV, like the UV-Nikkor, or a Coastal Optics UV lens.

Or you could find some older lens that works pretty good for UV-A.

Again, that is a whole other subject.

 

For Fluorescence photography, the lens will not matter, because you are shooting visual light.

 

Be careful about UV light, eyes, and the skin...

[Andy Perrin]

I mean, I guess if you are getting back clinically useful information from the UV exposure then you can justify it the same way we justify X-ray exposure, but obviously there must be some kind of balance to be found between the danger of the UV versus not having whatever info it gives you.

[The Skin Doc]

You put the lime in the coconut, you drink 'em both up!

 

TSD, I think you mean "UV bandpass", instead of 'bypass'.

No, that lens will not transmit UV.

Why would you need to use a telephoto for shooting skin?

 

I don't actually know how dangerous UV-A is for skin, your the doctor, not me, but UV-A is dangerous for eyes, and therefore any time you are shooting with a UV enabled flash or other UV light,

you should wear eye protection and anyone else present, such as your subjects. Possibly, just closing their eyes is enough, but again, that is your field, not mine.

 

I don't know if you are wanting to do UV-only photos or UV Induced Visual Fluorescence (UVIVF).

I have heard of some skin doctors examining skin with 365-UV ('Black Light'), to examine the fluorescence from the skin...

UV-only, and Fluorescence photography are two completely different things.

Actually, you can do fluorescence photography with the zoom lens, but that is a whole other subject.

 

If you are wanting to do UV-only photos (320nm-400nm), then you will need a lens that is friendly for UV, one that transmits UV-A as deep as possible.

You could get one of several scientific lenses specially made for UV, like the UV-Nikkor, or a Coastal Optics UV lens.

Or you could find some older lens that works pretty good for UV-A.

Again, that is a whole other subject.

 

For Fluorescence photography, the lens will not matter, because you are shooting visual light.

 

Be careful about UV light, eyes, and the skin...

 

I was in the process of buying a UV Bandpass filter. I thought that I could by a 77mm filter and a "Step-Up Adapter Ring" so that I could use the filter on both my Canon 70-200mm lens and 50mm lens. But I guess it's not possible. And yes I have my patients use eye protection as well as myself. Thanks so much for your advice. Much appreciated!

[Cadmium]

...and there are bandpass filters and 'bandpass filters'.

For example, Schott calls all their 'U' filters 'bandpass' filters, but they are actually dual bandpass, so used alone they transmit UV + red/IR, they work great alone as a dual bandpass IR filter,

but you need to stack them with BG glass or S8612 to suppress the Red/IR, and given the correct formula of U glass to BG glass, then it becomes a UV-only stack.

On the other hand you can also call a UV-only filter a 'bandpass' filter, because they are designed to be one true UV-only bandpass.

And you can probably use the zoom lens for dual band IR, as long as it doesn't have an IR hot spot, some lenses have IR hot spots, but I can't say about that lens, there are lists about such things.

An IR hot spot is a brighter circle in the center of the pic, not the same as lens flare (lines or circles sometimes seen in pics when shot toward the sun).

flare:

https://www.google.c...QEIOTAI#imgrc=_

 

However, the zoom is no good for UV.

Best to use a non zoom, something simple, there are lists of UV friendly lenses on here.

[bobfriedman]

read and heed.... most derm path is caused by UV from the sun.

[SteveCampbell]

Since your goal is UV portraits to show the effects of sun damage on a 5DmkIII, I assume you want (1) a flattering focal length, (2) a comfortable working distance with patients, (3) a lens compatible with Canon EF.

 

I would suggest going to eBay a searching for a Steinheil Cassar-S 50mm F2.8. The focal length is both flattering and comfortable for an office setting, while still giving you working room, the UV transmittance is deep at 315-320nm, and with an aperture of 2.8 shutter speed is less of a worry. You would need (1) very cheap Canon to M42 mount adapter (2) very cheap 40.5mm to 52mm step-up ring (3) 52mm S8612 and (4) 52mm UG11.

 

An alternative to the S8612+UG11 would be a Baader U 2" filter (52mm), which is expensive, but very high quality.

 

Additionally, adding a cheap 52mm to Canon EF Macro Reversing Ring would let you mount the 50mm lens backwards, giving you 1:1 magnification in case you wanted to image pigmented lesions in high resolution under UV.

 

Also cool might be a 720nm infrared filter in case you wanted to image hemangiomas or others highly vascular lesions in dark-skinned individuals (acts like a vein-finder). Might help differentiate pigmented vs non-blanching or vascular lesions in dark-skinned individuals, but just speculating.

 

A few other lens alternatives:

- EL-nikkor 80mm f5.6 or 105mm f5.6 - very high resolution, much smaller aperture, excellent UV transmittance, finding adapter can be difficult, need focusing helicoid

- Noflexar 35mm f3.5 (or it's clones) - Wider (shorter working distance), a littler small aperture than the Steinheil, very good UV transmittance, easy to adapt, higher resolution when reversed

- One of the really expensive dedicated UV lenses (~$10,000)

 

I'm sure there are many others that people here can recommend

[The Skin Doc]

Since your goal is UV portraits to show the effects of sun damage on a 5DmkIII, I assume you want (1) a flattering focal length, (2) a comfortable working distance with patients, (3) a lens compatible with Canon EF.

 

I would suggest going to eBay a searching for a Steinheil Cassar-S 50mm F2.8. The focal length is both flattering and comfortable for an office setting, while still giving you working room, the UV transmittance is deep at 315-320nm, and with an aperture of 2.8 shutter speed is less of a worry. You would need (1) very cheap Canon to M42 mount adapter (2) very cheap 40.5mm to 52mm step-up ring (3) 52mm S8612 and (4) 52mm UG11.

 

An alternative to the S86+UG11 would be a Baader U 2" filter (52mm), which is expensive, but very high quality.

 

Additionally, adding a cheap 52mm to Canon EF Macro Reversing Ring would let you mount the 50mm lens backwards, giving you 1:1 magnification in case you wanted to image pigmented lesions in high resolution under UV.

 

Also cool might be a 720nm infrared filter in case you wanted to image hemangiomas or highly vascular lesions in dark-skinned individuals (acts like a vein-finder). Might help differentiate pigmented vs vascular lesions, but just speculating.

 

This is awesome advice. I have a EF 50mm f/2.5 Compact Macro Lens. Would I still need a UV Bandpass Filter if I get the 52mm Canon Reversing Ring? I just went on eBay so I will be purchasing the Steinheil Cassar-S 50mm F2.8. This information is very helpful!

[The Skin Doc]

...and there are bandpass filters and 'bandpass filters'.

For example, Schott calls all their 'U' filters 'bandpass' filters, but they are actually dual bandpass, so used alone they transmit UV + red/IR, they work great alone as a dual bandpass IR filter,

but you need to stack them with BG glass or S8612 to suppress the Red/IR, and given the correct formula of U glass to BG glass, then it becomes a UV-only stack.

On the other hand you can also call a UV-only filter a 'bandpass' filter, because they are designed to be one true UV-only bandpass.

And you can probably use the zoom lens for dual band IR, as long as it doesn't have an IR hot spot, some lenses have IR hot spots, but I can't say about that lens, there are lists about such things.

An IR hot spot is a brighter circle in the center of the pic, not the same as lens flare (lines or circles sometimes seen in pics when shot toward the sun).

flare:

https://www.google.c...QEIOTAI#imgrc=_

 

However, the zoom is no good for UV.

Best to use a non zoom, something simple, there are lists of UV friendly lenses on here.

 

Thanks for the great advice. MaxMax suggested I buy a XNiteBP177: X-Nite Band Pass Series 1 (BP1) 320nm-670nm Filter in 52mm and stack it with a XNite33052C: X-Nite 330 Coated Filter in 52mm (to block IR light). This is a bit expensive, but if I can get the desired result then it will have been worth it. What do you think?

[SteveCampbell]

A bonus for the dermatologists in the room

 

 

~2.5mm freckle imaged in ultraviolet at high magnification with a 365nm light source

Canon EF to M42 adapter + M42 36-90mm helicoid + M42 to M39 + EL-Nikkor 5.6/135 + 43mm to 52mm step-up + 52/52mm reversing ring + 52mm UG-11 + 52mm BG40 + 52mm to 34.5 step-up + EL-nikkor 2.8/50

 

Edit: Excuse the lack of polarization. Normally I don't think you would get this type of reflection from the corneum with the Wood's light in a dermatoscope. I'll experiment later to see if it works at 365, but I'm pretty sure it would work at the normal 395nm for a Wood's light.

 

 

 

[SteveCampbell]

This is awesome advice. I have a EF 50mm f/2.5 Compact Macro Lens. Would I still need a UV Bandpass Filter if I get the 52mm Canon Reversing Ring? I just went on eBay so I will be purchasing the Steinheil Cassar-S 50mm F2.8. This information is very helpful!

 

No worries

Almost all modern lenses have specialized glass and coatings that block UV, so unfortunately that macro would also be of little use for UV. The Canon bit might still be suitable for infrared however. I would imagine the Steinheil would have higher magnification when reversed - I believe the Canon is only 1:2 magnification. You would have to stack the reversing ring and UV filters.

[SteveCampbell]

Thanks for the great advice. MaxMax suggested I buy a XNiteBP177: X-Nite Band Pass Series 1 (BP1) 320nm-670nm Filter in 52mm and stack it with a XNite33052C: X-Nite 330 Coated Filter in 52mm (to block IR light). This is a bit expensive, but if I can get the desired result then it will have been worth it. What do you think?

 

I'm not familiar with the MaxMax products, but I would imagine it would be both cheaper and likely more effective to go with the S8612 + UG11 stack, and definitely more effective but more expensive to go with the Baader U. Many of the people around these forums are optical engineers and endorse the UG11 + S8612 stack.

[Andy Perrin]

I like S8612 + UG11 and it’s worked well for me. Cadmium has mentioned in the past that he thinks U-360 is a bit better than UG11 if I recall correctly.

[ulf]

I like S8612 + UG11 and it’s worked well for me. Cadmium has mentioned in the past that he thinks U-360 is a bit better than UG11 if I recall correctly.

I can confirm that U-360 is a better alternative. I have tried both, in the real world with actual filters and with graph peeping.

 

I would recommend going for a 2mm S8612 + U630 2mm.

That S8612 thickness is efficient enough to handle almost all IR problems for different filter stack combinations, while still passing UV good.

 

S8612 1mm might work in some special cases if IR intensities are low with some filters, but the UV-pass difference is not that big to improve exposure time significant.

[Andrea B.]

Another vote for a U-360 (2mm) + S8612 (2mm) stack. Look for Uviroptics on Ebay for this. They sell authentic Schott or Hoya glass. UG11 is ok too. I just happen to be using U-360 right now. "-)

Uviroptics on Ebay will advise you.

 

If indoor exposures using U-360 + S8612 (2mm) are not bright enough with one flash from a UV-flash, then instruct the patient to sit still and increase the exposure time so that two UV-flashes can be made during the exposure interval. (Patient wearing UV-block eye goggles of course.)

 

SteveCampbell, thanks for all your good advice here for our Skin Doc. And the freckle shot is amazing! That is quite a rig you've put together there - awesome!

[SteveCampbell]

Looks like the consensus is U-360!

 

Thanks and no worries Andrea. Can't leave another medical islander hanging

[Andy Perrin]

Andrea, does it really need a full 2mm of S8612 to block that one?

[Cadmium]

Hoya U-360 is better than Schott UG1, they are basically equivalent, but for UV stacking U-360 works slightly better, two reasons, using the same thickness

 

1) U-360 cuts blue better,

2) U-360 has a higher UV peak amplitude transmission.

 

...and yes, also I prefer the U-360 stack more than the UG11 stack.

 

UG11 is best if you want the UV peak to be a lower/deeper nm, UG11 reaches lower into UV, it has a wider deeper UV transmission, however stacking with even the deepest UV transmitting BG glass (S8612) will cut off the deeper reach of the UG11. Only if you you use very thick UG11 and quite thin S8612 (3.5/4.0mm UG11 + .75/1.0mm S8612, for example) will you move the UV peak lower (for example, about 340nm with that stack mentioned), which will outreach or strain the UV capability of many lenses, so such stacks are not very practical for most lenses, and I have not tried it with a UV-Nikkor or the like, so I can't advise on the results of that.

 

Typical suggested UG11 or U-340 stacks are:

• U-340 or UG1 (2.0mm) + S8612 (1.5-2.0mm)
  1.75mm provides OD5, 2.0mm = OD6, for that stack.
  

• UG11 (1.0-1.2mm) + S8612 (2.0mm)
  

 

If you want to use U-340 instead of UG11, then you should design a stack formula that uses thicker U-340, because it does leak a little 500nm range visual when thin, which is hard to 'see', in photos, but in fact you can even see it with your eyes, given the right light and dark room. You should not use U-340 thinner than 1.5mm or maybe 1.75mm, in my opinion. UG11 is twice the price of U-340 however, but it blocks the visual range better at the same thickness.

 

Back to U-360, not only does it work better, but it is less expensive. Some suppliers are selling Chinese glass and naming it Hoya and Schott names, this is obvious to me by the prices. If you want Chinese glass, buy it directly from China, but it is not as efficient as the real thing, and you will not know the difference unless you have them side by side, then it is immediately apparent.

 

The U-360 (2.0mm) + S8612 (1.75/2.0mm) stack is the best, it shares the same white balance with the Baader U and is hard to see a difference. With most lenses you realize no more UV depth from a Baader U than the U-360 stack, given the lens transmission truncation of the filter depth, and even with a UV-Nikkor it might be a little hard to see any difference because the drop off of the sensor.

 

The U-360 stack is about $200 less than a Baader U, and can be made in any size. The stack can be glued, or stacked as separate filters. It is cheaper than any other stack, except those made of Chinese glass and wrongly labeled Chinese glass.

 

For flash, U-340 (2.0mm) is best to use, it works great, and is much less expensive than UG11. You will need to stack it with S8612 (2.0mm) to block the red/IR. Some use just the U-340 alone for fluorescence, but I prefer removing the visual red from the UV light. The U-340 (2.0mm) + S8612 (2.0mm) is the recommended stack for full spectrum flash.

 

For 365nm Nichia LED torches, you only need the U-340 (2.0mm), because those don't emit any red, just fairly narrow band UV, but a little blue may be seen, so that is why you use U-340 to cut block any blue. People sometimes ask why U-360 or UG1 is not better to use for flash and torches... the reason is because UG11/U-340 works better for cutting below 400nm, eliminating any possible blue leak.

So I recommend U-340 (2.0mm).

 

The "Uvex Ultra-Spec 2000 Safety Glasses - Amber" are my personal favorite UV eye wear now, because they fit easily over glasses, and my tests show they block everything, even blue.

https://www.fullsour...om/uvex-s0290x/

 

There is more info/tests here:

http://www.ultraviol...dpost__p__19965

[Andrea B.]

That is an excellent summary of the UV-pass filter glass! That post needs a bookmark.

[ulf]

I agree.

There is not any detail I would like to change or that I can see missing.

Very well written Steve!

 

The post would fit very well among the filter stickies.