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Boston's Citgo sign


Andy Perrin

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It was suggested to me by nfoto that the AF-Nikkor 80mm/2.8 was a good sharp lens with adequate UV bandpass, and so it seems...this copy was recommended to me by nfoto herself, and I'm happy with it, so many thanks.

 

F/5.6 1/4" ISO1600

1.75mm S8612 + 2mm UG11

In-camera white balance off the road, and saturation/contrast increased.

post-94-0-01205300-1582414544.jpg

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Seems crisp enough to me ... did the metering work? There was an incompatibility with the earlier Nikons regarding the CPU contact pinouts, would be nice to know whether the metering issue is handled by modern cameras.

 

You really got a bargain on that lens, by the way. The seller claimed "AF not working" as a major flaw, which is rather irrelevant as the lens was designed for the F3AF back in the early '80s. However, due to seller's lack of insights, the price was slashed by 50% or more.

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I am not sure how I would get the metering to work, assuming it does? I have a Sony A7S. My adapter doesn't seem to have any provision for electronics so I wouldn't expect the metering to work as things are? There may be more expensive adapters that can do the electronics, but I don't own them yet...
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Well, if you have a yellow sky that should be a good sign, since Rayleigh scattering is stronger at shorter wavelengths (and sunlight intensity decreases at shorter wavelengths). I get pretty much colorless skies, and a 2 mm thick chinese BG39 is almost colorless, just a pale blue. I don't think my lens/filter setup reaches very deep into UV.
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Well, if you have a yellow sky that should be a good sign, since Rayleigh scattering is stronger at shorter wavelengths (and sunlight intensity decreases at shorter wavelengths). I get pretty much colorless skies, and a 2 mm thick chinese BG39 is almost colorless, just a pale blue. I don't think my lens/filter setup reaches very deep into UV.

I have that chinese filter also. I could not get it to suppress IR enough for any filter. What do you stack it with?

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Namestom, with the Chinese filters you never know what you are going to get. Even two similarly labeled filters may not behave the same way. That's why Andrea, Cadmium, etc. recommend against them.
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Andy, Great photo, I know it is just a sign, but I like it.

You have me tempted to get the lens and compare it to the Kyoei 80mm f/3.5.

I can't imaging the lens you are using would transmit as deep as the Kyoei, but it might be a lot easier to use, especially on a Nikon camera.

The Kyoei is quite hard to find also.

 

Keep in mind that although you both have a Chinese BG39 they may not be the same, even at the same thickness.

Those are not made by the same company, they are made by who knows how many companies, in their different kitchens, like soup, almost the same, but not consistent, even when from the same kitchen.

Military contractors are held to tight standards, other manufacturers also, aerospace, medical, or whoever else wants to make reliable, consistent, and safe products.

They never use Chinese filter glass, nor a lot of other brands of filters glass, because they don't meet specifications or tolerance. Chinese glass is not documented.

Schott and Hoya filter glass meets specifications and consistencies. Each batch (or 'melt') is tested, recorded, individually documented, and made available as melt data.

One of the reasons that Schott filter glass is the best is because of their much superior up-front transmittance data, shown on their data sheets,

and used in their filter calculation program, which makes it easy to calculate what to expect accurately.

 

What color the sky? There again, I would recommend you start with a known filter to base such a judgement on. I would mention white balance also, but let's not right now.

 

Here is an example of the melt data sheet for a batch of Schott S8612. What it shows is deviation from optimal norm. Military contractors probably have file cabinets or hard drives full of these,

and certificates of compliance also.

post-87-0-86234200-1582518957.jpg

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What color the sky? There again, I would recommend you start with a known filter to base such a judgement on. I would mention white balance also, but let's not right now.

Indeed, let's not, because I simply took a white balance off the street! Adequate for art's sake but hardly scientific.

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Andy how does the UV transmission compare to the Nikkor 80mm EL? Is it similar, even though the EL is f5.6 or is the AF-80 actually 2 stops faster?

 

I ask as I find the EL to have exceptional UV transmission.

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Yeah, the EL 80 is one of the best UV transmitting, but needs a helicoid. So is the Kyoei 80mm, great, but is a normal lens with built in helicoid and M42.

I really like that Nikon AF-Nikkor 80mm/2.8, but it will only do auto-focus on a couple special Nikon cameras. So it just becomes another manual lens on my Nikon cameras.

I would buy one, other than that, even just to do a Sparticle test comparison.

I sure wish it did auto-focus on my Nikon cameras, I would get it just for visual or IR, regardless of how well it transmits UV.

So, holding myself back from getting one.

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Yeah, the EL 80 is one of the best UV transmitting, but needs a helicoid. So is the Kyoei 80mm, great, but is a normal lens with built in helicoid and M42.

I really like that Nikon AF-Nikkor 80mm/2.8, but it will only do auto-focus on a couple special Nikon cameras. So it just becomes another manual lens on my Nikon cameras.

I would buy one, other than that, even just to do a Sparticle test comparison.

I sure wish it did auto-focus on my Nikon cameras, I would get it just for visual or IR, regardless of how well it transmits UV.

So, holding myself back from getting one.

 

Cadmium,

Do you have a Nikon AFD 105mm f2.8 macro lens?

I found that it has great UV transmission and supports AF on all F-mount cameras with a screw drive motor. Sadly that excludes the current Z-mount cameras as no screw drive.

I got mine during the Z mount announcement at what I consider a fire sale price. Missed out on $120 60mm AFD macro. But was similar.

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Steve: the AF 80/2.8 does equally well -- if not better -- in IR. Add its capabilities in visible and it becomes a truly all-rounder.
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Why not just tiffen #12?

I did a thread on that question here:

https://www.ultravioletphotography.com/content/index.php/topic/3337-irg-with-one-shot-using-a-db850-tiffen12/

 

Long story short, Tiffen#12 by itself does not allow you to take a true IRG (infrared-red-green) image because IR in the 720-830nm range gets added unequally to the red and green channels. The DB850 filter removes this range, which then means that the contribution of the IR is the same to all three channels and the image subtraction will work the way it's intended to.

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David and Birna,

I don't know about the 105mm version, but the 80mm has no provision for motor focus from the camera, it is made to auto-focus on just one of two Nikon cameras.

I am sure it does quite well in visual and IR, and it is sharp, but it still will not auto focus.

The interesting thing about the 80mm is that it has good UV transmission, but good compared to what, I can't say.

So it is a sharp manual lens that so far has an undocumented UV transmission.

 

Will not auto-focus:

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I did a thread on that question here:

https://www.ultravio...db850-tiffen12/

 

Long story short, Tiffen#12 by itself does not allow you to take a true IRG (infrared-red-green) image because IR in the 720-830nm range gets added unequally to the red and green channels. The DB850 filter removes this range, which then means that the contribution of the IR is the same to all three channels and the image subtraction will work the way it's intended to.

Interesting, I tried to stack the #12 with the tiffen hot mirror which has a sharp cut off at 750nm. It was cloudy that day and didn't work well. Ill revisit that on a sunny day. Can't wait to see your results.

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Interesting, I tried to stack the #12 with the tiffen hot mirror which has a sharp cut off at 750nm. It was cloudy that day and didn't work well. Ill revisit that on a sunny day. Can't wait to see your results.

 

That may not work. Your hot mirror cuts off everything above 750nm.

The DB850 filter is a dual band filter, thats the DB part. It has transmission in the visible plus 800nm to 900nm IR spectal area see its spectrum here:

https://midopt.com/filters/db850/

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Andy,

I still want to see the exposure settings for the same thing with same light source photographed with the EL 80mm f5.6 and the AF80 f2.8.

Is the AF80 2 stops faster when both lenses are wide open?

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That may not work. Your hot mirror cuts off everything above 750nm.

The DB850 filter is a dual band filter, thats the DB part. It has transmission in the visible plus 800nm to 900nm IR spectal area see its spectrum here:

https://midopt.com/filters/db850/

Correct. It needs to be the special dual-band filter to work properly.

 

Dabateman, when I get time, okay?? Work is going crazy right now! I wanted to do a with-and-without DB850 test also for Clark.

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