UV with the D800M + Noflexar 35/3.5

[bobfriedman]

Not a very strong UV day...

 

D800M = Monochrome Sensor Conversion

 

Nikon D800M ,Noflexar 35mm f/3.5 ,Baader U-filter

1/30s f/5.6 at 35.0mm iso800

http://www.pbase.com/bobfriedman/image/167618427/original.jpg

 

Nikon D800M ,Noflexar 35mm f/3.5 ,Baader U-filter

1/25s f/5.6 at 35.0mm iso800

http://www.pbase.com/bobfriedman/image/167618347/original.jpg

 

Nikon D800M ,Noflexar 35mm f/3.5 ,Baader U-filter

1/15s f/5.6 at 35.0mm iso1250

http://www.pbase.com/bobfriedman/image/167617992/original.jpg

[Andy Perrin]

Back at Mt Auburn? Lovely pics as always, Bob.

[bobfriedman]

yep.. need to find some other places..

[Andy Perrin]

Boston Public Garden?

[bobfriedman]

Boston Public Garden?

 

yep, i have a lot of IR shots from there... not as good as Mt. Auburn.. actually as a National Landmark Mt. Auburn is hard to compete with in this area.

 

was thinking of Searles Castle, Windham, NH

[Andy Perrin]

I looked that place up once, and I gave up on it because it seems everything has to be arranged in advance, you can't just walk in and buy tickets.

[Cadmium]

Bob, Nice to see UV shots with your D800M. Can't really make up my mind here, maybe the top one. ISO 8000 (oops) 800 (I meant) and 1/30s seems good.

[bobfriedman]

Bob, Nice to see UV shots with your D800M. Can't really make up my mind here, maybe the top one. ISO 8000 and 1/30s seems good.

 

ISO=800

[bobfriedman]

I looked that place up once, and I gave up on it because it seems everything has to be arranged in advance, you can't just walk in and buy tickets.

 

that wouldn't be good... i will call them

[Andrea B.]

Of course, as a passionate amateur botanist, I am fascinated by the first photo. B)

 

And I'm wondering what that massive tree is in the 3rd photo? That trunk is huge!!

 

It's nice to see this good work with the Noflexar 35/3.5. I've always enjoyed that lens.

[bobfriedman]

i purchased the Noflexar in 2008 or maybe 2007... and i haven't used it until now....

[Andrea B.]

Really ?!!!??

Well, you certainly put it to good use in this set. :D Looks like you have a good copy too.

 

35 mm on a full frame has always been my favorite framing for landscaping and general photography. I also like 28 mm quite a lot.

I've never felt comfortable with 24 mm. Which is sort of goofy given that it is so close to 28 mm. Go figure.

[bobfriedman]

i wish i could find a UV capable wider than 35mm that provides infinity focus on my D800M

[OlDoinyo]

Will Nikon bodies accept M42 or T2 with an adapter? If the former, the Tamron 21/4.5 and the Asahi 20/4.5 are both possibilities. I am less sure about T2, but there are some wide-angle optics in that mount as well. You won't get the bandpass with those shorter lenses that you will get with the better 35s, because of the thicker glass.

[ulf]

No the M42 will normally not work to infinity as the register / back flange distans is shorter than the Nikon bayonet distance.

That would require an adapter with negative thickness.

Those are quite rare. ;-)

http://www.graphics....y-register.html

Sometimes it is possible to readjust the focus on older lenses, enough to reach infinity, depending on their mechanical design.

 

A lens with a T2 style mount and a T2 - Nikon adapter would work, if I understand tings correctly.

If you find any suitable lens with T2 mount, you could just replace the adapter with a T2 - Nikon adapter, if the T2 adapter of the lens was for a different camera type.

http://camera-wiki.org/wiki/T_mount

[Cadmium]

Ulf is right, Nikon will not work with M42 for infinity, but I use one of these cheap infinity converters below. It has a built in lens (hard to see in the photo below).

The cheap ones use BK7 glass (probably) which passes UV down below 300nm, and have no coating, so this one (for example) passes UV deeper than the Kuri and/or a Baader U.

Works great.

[bobfriedman]

so the Noflexar that i used had just such an M42 to F-mount with meniscus lens adapter.

[ulf]

I wonder how much such an adapter affect the optical quality of the image system.

The dispersion of the BK7? lens must cause some CA and other deviations from the original performance of used lens.

 

Bob, if you have a glass-less M42 to F-mount too it would be interesting to see the difference for some macro images with the Noflexar.

[bobfriedman]

i am sure there are degrading effects (aberrations, etc. ) of the meniscus lens... however, the Noflexar is no great lens either... that is probably why it works in the UV :)

 

while aberrations may be introduced i am not sure what you mean by CA?... is there such a thing in the UV?... especially with a monochrome conversion..

[ulf]

Chromatic Abberation, a quick recapitulation:

 

Optical materials refract light differently for different wavelengths, causing CA.

There are two types, transversal and lateral CA.

One causes image magnification differences for different wavelengths, the other is causing focus shift.

 

Unless you use monochrome light, CA will affect the image quality with a Bayer matrix, causing coloured fringes, without a Bayer matrix causing blurring.

As the wavelength span we use is rather narrow it might not be as much problem as in VIS, but at the same time we are outside the wavelength range the lenses are designed for and the aberration might be more severe.

[OlDoinyo]

So it appears that the Nikon mount is cursed with a long FFD and this limits its ability to accept other lens types, analogously to the way Canon EF cameras cannot take older FD/FL glass because the FFD increased.

 

My experience with those optical compensating adapters is not good--they can truncate the image circle in addition to being optically poor.

 

I cannot vouch for the bandpass or other UV properties of the following; I simply throw them out there in case they are of some interest.

 

-Tamron Adaptall (requires appropriate adapter for mount.)

 

28/2.5 https://www.ebay.com...-kAAOSwlgNbFZAE

 

24/2.5 https://www.ebay.com...EYAAOSw0O9bIc8W

 

-T2 mount:

 

Vivitar 28/2.8 https://www.ebay.com...6cAAOSw2B5ZzDvS

 

Soligor 28/2.8 https://www.ebay.com...WcAAOSwb9Bar8XZ

[bobfriedman]

without a Bayer matrix causing blurring.

As the wavelength span we use is rather narrow it might not be as much problem as in VIS

 

ok.. about 50nm max... seems unlikely.. but if it exists i am sure the noflexar + meniscus has it :)