23 replies to this topic

[nfoto]

I thought it could be beneficial to collect examples of the most surprising lenses capable of returning a decent UV result.

I'll start with the Zoom-Nikkor 200-600mm f/9.5 AIS which was the latest incarnation of a complex zoom design Nikon launched many many years ago. In fact, the very first version was released in 1961 (!). My sample is from 1982, so carries a pretty respectable age by now. There are no less than 19 elements inside, so normal considerations say this is not a lens for UV. Accordingly I used it for IR on my modified Nikon D5300, seen below.



As typical of these early Nikkors, the workmanship is exquisite and handling is extremely nice as it balances perfectly on a tripod. Focusing and zooming controls work smoothly despite the advanced ago of the lens.

Being what I am, curiosity got the better on me a few years ago when I saw these Caltha palustris flowers along a small river. The distance to the Marsh Marigold stand was too long to do much good with my UV-Nikkor, thus I attached the 200-600 lens to my trustworthy Nikon D3200 (built-in Baader U, very useful) and fired away with the lens set to 600mm focal length.

This is what I got. Big surprise. The classic large UV-dark patches on the basal section of the honey leaves are exactly as expected.



Exposure was f/11, 0.8 sec, ISO 800, which given the rather pale, hazy spring sun was indicative of surprisingly good UV response. No, the lens will not likely go deep into the UV bands, but it certainly made my day.

[StephanN]

Very interesting.

I'm sure you've written it somewhere already, but who put in the Baader U-filter for you?

[colinbm]

Nice surprise Birna

[nfoto]

StephanN, on 22 February 2021 - 11:09, said:

Very interesting.

I'm sure you've written it somewhere already, but who put in the Baader U-filter for you?

Courtesy of Vivek Iyer. He originally cut the filter for a D40X, and I transferred the filter to a Nikon D3200 later.

[Stefano]

This shows that, although it is good to make assumptions, one just never knows until experimenting. It is always worth it to give it a try.

[dabateman]

Wow I love the look of that tripod and plates. What is that?

[UlfW]

All of it looks heavy

[nfoto]

dabateman, on 22 February 2021 - 12:52, said:

Wow I love the look of that tripod and plates. What is that?

Sachtler ENG CF 2 HD with Sachtler Video 20 Fluid Head. An overkill granted in this case, but I had just used the 'pod for my 360-1200 Nikkor which really needs this kind of support system. The lens is mounted via a sandwich of Foba Arca-type clamp and an interface to the Sachtler video plate mount of the fluid head.

The tripod easily supports 100 kg loads, by the way. Yet only weighs 4 kg on its own.

[UlfW]

nfoto, on 22 February 2021 - 14:56, said:

Sachtler ENG CF 2 HD with Sachtler Video 20 Fluid Head.
The tripod easily supports 100 kg loads, by the way. Yet only weighs 4 kg on its own.

And then you have 4 kg more for the head, plus lens and camera.
Not something to take along on a longer hike, at least not if you are as lazy as I am.

[nfoto]

I can agree to that. Unless you have a field assistant .... This is after all a tripod primarily designed for video/cine and TV crews.

The slightly more "normal" Sachtler tripods employed by me range from 0.6 to 2.4 kg, and heads are << 1 kg on all.

[Andrea B.]

I used one of Birna's Sachtler tripods during the Norway Safari of 2014,
and I gotta say that those tripods really rock -- as in, they are rock-solid.

[Cadmium]

Great equipment! The lens is really nice, and the tripod head with two handles... A helmet and leather jacket may be in order I think!

Edited by Cadmium, 23 February 2021 - 03:23.

[nfoto]

I have a black leather jacket -- will it do?

[Cadmium]

He he he, yeah.
The handles, do they twist to lock and unlock the head?
I can only afford the lens, but I have not seen that exact one yet.
I do have one of your other lenses you recommended once (other than your lens page), let me see if i can find it for exact reference.hold on, here it is:

This is a nice solid lens, older, auto focus, very mechanical but works great, I just don't use it, cool lens though.
Nikon AF Nikkor 35-105mm, f/3.5-4.5 D. HB-5 hood.
Works fine for IR.

Edited by Cadmium, 23 February 2021 - 05:40.

[nfoto]

The handles are for navigating the fluid head. The head itself has separate locking levers for swing and tilt, however due to its heavy damping the traditional "locking" of the head is rarely employed.

As to the 200-600, it is not a very common lens and approx. 500 units of the AIS version were produced, for the earlier versions in total 4-5000.

The AFD 35-105 is a very good lens for IR if you can live with the massive focus shift.

[UlfW]

With a lens design with that many lens elements I suspect that there are considerable light loss even if the UV-transmission is good enough.
It is quite unlikely that any AR-coating is enhancing the performance far into UV-A.

One way to test this would be to compare exposure times between this lens and the well documented UV-Nikkor 105mm.
The lenses should have the same aperture setting during the test.

The test target can be something reasonably UV-White, illuminated with a freshly charged Nemo flashlight.
For such a test the lenses do not have to be focussed.
The exposure time difference gives an indication of the general intensity loss at around 365-370nm.

Edited by UlfW, 23 February 2021 - 08:22.

[nfoto]

My best estimate at present is the 200-600 is about -3 or -4EV compared to the UV-Nikkor. Which is fairly normal. Obviously the 200-600 is *not* the one-lens-rules-them-all approach to UV photography, but even this non-specialised optic can do service in a pinch, which the whole experiment was about.

[dabateman]

What we all shouldn't be using a 600mm lens for UV photography!
First we all have to use a 35mm f3.5 lens and now that a 600mm appears we are told not to use it for every shot.

I guess the UV portraits will suffer. A 600mm would just melt that hideous bumpy speckally nose into the freckled face.

All above a joke of course. We all know that the Sigma 30mm f2.8 Art is the only lens for UV photography. Thats why its no longer for sale, must be exclusive.

Sadly I can't afford to even dream about that tripod or acknowledge its existence. Thats some serious gear. Being heavy into micro four thirds I don't even need it as my heaviest lens is the old four thirds 50-200mm f2.8/3.5 with m43rds 1.4x and either four thirds 1.4x or 2.0x tele converters. Interesting you can mix the micro and four thirds teleconverters to get autofocus. So 1.4x +2.0x +200mm = 560mm or 1220mm 135 format equivalent with autofocus is crazy.

I saw the first version on the bay yesterday of this lens, the 20cm to 60cm for $250. Was almost tempted. But I want everything autofocus now. Including the six fused silica lenses I just built. So one day a Megadap adapter and Nikon z7 or Z5 will be in my future. Can't afford the tripod, I keep wanting more cameras.

[Reed F. Curry]

Back in 2016 I was playing with this - https://www.ultravio...__fromsearch__1 but never got around to making a proper UV bandpass filter for it. I found it again last week and it is such a nice glass that I am re-inspired. True, with 14 elements in 10 groups, I don't expect a high UV transmission, but the zoom is really slick. :)

[UlfW]

nfoto, on 23 February 2021 - 09:47, said:

My best estimate at present is the 200-600 is about -3 or -4EV compared to the UV-Nikkor. Which is fairly normal.

Then I am quite convinced you would find the UV-transmission from a long Noflexar 400mm or 600mm as a very nice surprise.

My preliminary measurements of absolute transmission for Novoflex Fernobjektiv 40cm, Noflexar 400mm and Noflexar 600mm indicates that those lenses has similar or better transmission than the UV-Nikkor's stated 72%, at 365nm.
Only the T-noflexar 400mm has a few percent lower transmission at 365nm (ca 70%)

The disadvantage with these lenses is that the burden for your field assistent will be smaller as the are not so heavy.

Now I just have to postprocess the spectral data.


I posted about those lenses two years ago here:
https://www.ultravio...__fromsearch__1
The transmission graphs are reasonably correct already with a normalisation to 100% at 420nm.
In reality, the absolute transmission at 420nm is above 90% for all except the T-Noflexar 400mm that only reaches 83% at that wavelength.

Edited by UlfW, 23 February 2021 - 15:58.