UV Apple

[eye4invisible]

Hi All,

I've been away from this forum for quite awhile due to work commitments, but it's great to be back and to share some of my UV shots with you.

 

This one was taken with my full spectrum Nikon D3200, the 18-55mm kit lens @ 55mm, f/5.6 (max available aperture for 55mm) and 8 sec shutter speed, ISO100. White balance is notoriously difficult to set on a D3200, so I usually just set the CWB against a white sheet of paper with the lens filter off (ie. in full spectrum mode) and then screw the lens filter on.

 

The UV filter used was the Kolari Vision UV bandpass filter, which claims 50% transmission peak at 365nm, and >25% transmission between 340-380nm. Colour cast is almost identical to a B+W403 and S8612 stack, but the shutter speed seems to be a little faster than the later combination, presumably because it cuts less UV than the S8612 does.

 

I shot this raw (NEF) and used Nikon's Capture NX-D with the WB dropper against the metal fruit basket frame, then cropped, enhanced and re-sized the image in Lightroom (didn't change any HSL).

 

The apple was a reddish hue in the visible spectrum (think it was an Empire apple). I don't remember much else, other than the fact that it was delicious! :)

 

What interested me the most were the spots (almost like leopard spots) around the hole where the stem usually is. These were not apparent to the human eye.

 

 

Regards,

Andy

[Cadmium]

Any, Nice to see you back! Nice shot.

So is the brown/red I am seeing visual red/IR? Or is that just the white balance?

[eye4invisible]

So is the brown/red I am seeing visual red/IR? Or is that just the white balance?

 

Great question. I think it has more to do with the white balance than anything else.

 

If I set the WB dropper on the apple instead of the metal fruit basket, I get a blueish cast to the photo. Here's a screen-grab of the raw NEF:

 

[Cadmium]

It would really be hard to say with out comparing two shots, UV shot and isolated visual/IR range shot.

Easy to do by stacking some longpass filter on the U filter that blocks UV but transmits red/IR range, using the same exposure time as the U filter shot.

That will show you if there is any red/IR in the mix, if you use the same exposure time.

 

Let me address your conclusion about S8612 as quoted below:

"The UV filter used was the Kolari Vision UV bandpass filter, which claims 50% transmission peak at 365nm, and >25% transmission between 340-380nm.

Colour cast is almost identical to a B+W403 and S8612 stack, but the shutter speed seems to be a little faster than the later combination, presumably because it cuts less UV than the S8612 does."

 

You are stacking UG1 2.2mm with S8612 3mm (B+W 403 is UG1 2.2mm thick), that is why your exposure time is longer with that stack.

That stack has slightly less than 40% peak UV, and Red/IR suppression of almost OD 8 because the S8612 is 3mm thick.

All you need is OD 4 or 5, anything more is not needed, but causes loss of UV peak amplitude, which makes exposure time longer.

If you stack UG1 2mm with S8612 1.5mm will get 50% UV peak transmission (T) at 365nm, and >25% UV transmission between 340-380nm. OD 5 suppression.

If you use U-360 2mm + S8612 1.6mm you will get an even higher UV 58% peak transmission (T), and reduced blue. OD 5 suppression.

 

The KV U is a UG1 type + BG type stack. That is why the 'color cast' looks similar.

I can't say what type of BG is used, but I can say that S8612 is the best BG glass for UV stacking, because it has the best UV transmission to Red/IR suppression ratio of any BG type glass,

and there is no equivalent made for S8612.

 

Thicker than needed BG glass (such as S8612 3mm) will reduce UV peak and increase exposure time, and that is true of any thicker than needed BG glass type.

 

Sorry if that is so long winded.

[eye4invisible]

The KV U is a UG1 type + BG type stack. That is why the 'color cast' looks similar.

I can't say what type of BG is used, but I can say that S8612 is the best BG glass for UV stacking, because it has the best UV transmission to Red/IR suppression ratio of any BG type glass,

and there is no equivalent made for S8612.

Sounds like this is exactly what KV is doing with their filter - using the 2mm UG1. Might have been cheaper to simply buy a thinner S8612, but I'm glad to have a backup/spare filter.

 

Sorry if that is so long winded.

Not at all - I appreciate the info.

 

Unfortunately, as much as I like UV photography, I'm on a fairly tight budget. I can only dream of purchasing a Jenoptik CO60!

 

Until then, I'll have to stick with either the 18-55mm kit lens with a tripod, or the Nikkor 50mm 1.8D.

[Cadmium]

Andy, The 18-55mm VR kit lens is what I use on my DX for visual and IR probably 90% of the time, but it isn't exactly good for UV.

You don't need anything fancy like the CO60, you will not get much more out of those than an affordable UV capable lens like below.

There are a number of UV capable lenses, Kuribayashi 35mm, or one of the similar lenses, or the El-Nikkor 80mm, but that would need a helicoid for focus.

I am sure you can get lots of recommendations for UV lenses from people.

[ulf]

There are a number of UV capable lenses, Kuribayashi 35mm, or one of the similar lenses, or the El-Nikkor 80mm, but that would need a helicoid for focus.

I am sure you can get lots of recommendations for UV lenses from people.

 

I would recommend the EL-Nikkor as the Kuri-lens is very rare.

I haven't seen a real one for quite some time on eBay.

 

There are several lenses similar to the Kuri by Soligor etc. and even if they also reach deeper into UV, the image quality of mine is not that impressive.

The rather small difference in UV-range is not that important if you are not experimenting with narrow bandwidth filters at 340nm or shorter.

 

The optical quality of the EL-Nikkor lenses is also quite high.

[Cadmium]

Well, indeed, the Kuri is kinda hard to find, but the Kyoei 35mm is the same, both are hard to find, but for a Nikon camera, I prefer those because they don't need a helicoid, although they need an infinity adapter.

If you can find a Kuri 35mm for less than $150, grab it, it is the best lens for UV unless you want to pay thousands.

Thing is, most UV filters only pass down to about 320nm, and the sensor is only sensitive down to whatever... 300-nm?

So grab one if you find one. You will find one.

[eye4invisible]

If you can find a Kuri 35mm for less than $150, grab it, it is the best lens for UV unless you want to pay thousands.

Yes, I was looking at this eBay listing yesterday: https://www.ebay.com/itm/Kyoei-Kuribayashi-T-Mount-Variant-35mm-F3-5-Lens-Filter-Set-UV-Photography/273112274099

 

Not particulary interested in the filters that come with it (maybe I can knock down the price by asking to buy only the lens) but this Kyoei clone is in a T-mount (I found a T mount to Nikon F mount for about $20.00 on Amazon). How do these clones compare to the original Kyoei 35mm lenses for UV?

 

I bought a Nikon AF 50mm f/1.8D lens based mostly on the recommendation of this article: https://kolarivision.com/uv-photography-lens-compatibility/

 

How does the Kyoei (or the clones) stack up against my Nikon 50mm?

[eye4invisible]

The optical quality of the EL-Nikkor lenses is also quite high.

When you say optical quality, are you referring to focus shift (or, rather, lack of it)? For me, the focus shift is the biggest problem. The Nikon AF 50mm F/1.8D that I got helped with the shutter speed, but it didn't seem to make that much difference to the optical quality as far as focus shift.

[Andy Perrin]

I thought he just meant it was a good lens (i.e. contrast is high at the edges, even when it's not stopped down)?

[ulf]

I have with few exceptions used the lens for macro 1:5-1:1 and stopped down to 1/11 - 1/22 and cannot tell how it performs wide open.

 

There has not been any problems I have noticed with focus shift or disturbing chromatic aberration.

I often take multispectral image series from UV to NIR and see more focus shift due to total thickness difference filters and filter stacks.

 

The lens is quite sharp and has good contrast.

 

I have not made any test target lens tests for this lens.

[Cadmium]

Andy, that 'clone', or best to call it a suppose to be clone, and an unknown clone... because it doesn't say exactly what lens (brand) it actually is.

Yes, it looks similar to a Kuri/Kyoei, but unless we have a know test of that lens (brand), then we don't know how it compares.

In my opinion, the item should be listed with the actual brand name of the lens, but instead it is listed with the Kyoei and Kuribayashi names, to attract attention, no real problem there, but keeping the real brand name of the lens a mystery...

that part to me is not good, and that kind of reverses the OK'ness of using the Kuri name in the listing.

If the listing said the brand name of the item, then we could search and see who has testing it, compared it, but we can't, and to it is a mystery.

Anyway, I have said all this before.

 

Not all 'clones' are created equal, so it might be best to pick out some clone that someone has tested, compared with the Kuri/Kyoei, and search for one of those specifically, then you know what you are getting,

You don't need the china filters either.

Take a look at Enriko's comparisons:

http://www.savazzi.n...phy/35mmuv.html

 

By the way, that S8612 3mm thick filter you have is not really practical for most things. If you want to swap it for a 2mm thick version, I think you would get a lot more use out of 1.5mm to 2mm thick.

I think I would get a 2mm thick, best for all around use.

I never use 3mm for anything except strange tests, never for actual photography or stacking.

[ulf]

One important aspect to consider when selecting a lens is what type of motives it is intended for.

The focal length or FOV can also be important.

 

If the motives are landscape and urban photography, a wide lens with short focal length as the Kuri might be a good alternative.

However you have to add an optically low quality adapter to reach infinity on a Nikon DSLR.

 

If macro and closeup is the main motive, the Kuri-lens might be less useful. The near limit seams to be 0.9m.

Extension tubes helicoids and bellows are not very practical together with the lens as it will need a rather short extension and it is difficult to reach low magnifications near the 0.9m above.

 

I have not done much landscape and urban photography, with my Baader U, but it seams to be rather rare to see indications of shorter wavelengths, as false yellow, in those types of motives.

That makes me believe that a deep UV is not as important as it is for macro of flowers and similar.

[Cadmium]

Well, you can't do those extreme close up fly shots like you did with this 35mm, but you can easily get an inch away from something with a short extension ring.

Also, that 0.9m is less than that on a Nikon with a non infinity M42 adapter.

I do flowers easy with this, and close if I want to put a short extension between the lens and camera.

Best you can get for landscape, but that will need the adapter type with the infinity lens built in.

If you want to use something that is wider for landscape, there are none available with UV transmission like this.

The Apple above would be easy with no extension and just the standard simple M42 adapter with no infinity lens.

Also, the Kuri has the least focal shift of any lens I have ever seen or used. In live view, that may make no difference, but in other ways it may still make a difference for the user depending,

at any rate, it is a quite unique aspect of this particular lens, and I am not aware how other 'clones' compare to the non-focal shift of the Kuri 35mm.

[eye4invisible]

The Apple above would be easy with no extension and just the standard simple M42 adapter with no infinity lens.

Also, the Kuri has the least focal shift of any lens I have ever seen or used. In live view, that may make no difference, but in other ways it may still make a difference for the user depending,

at any rate, it is a quite unique aspect of this particular lens, and I am not aware how other 'clones' compare to the non-focal shift of the Kuri 35mm.

Thanks again. I am going to give that clone a miss - I'd rather not take chance in case it isn't up to par vs a genuine Kuri. I'll keep looking for the Real McCoy.

 

The 35mm seems like a good balance for landscape, macro and maybe even some portraiture.

[OlDoinyo]

They may not have quite the bandpass of the best Kuribayashis, but the older Asahi 35mm Takumars are very sharp with relatively little CA and focal shift (mine is the sharpest UV lens in my possession.)

[ulf]

I bought one of those after I saw DonPilous post mentioning the lens.

 

The lens is quite sharp.

In that aspect it is much better than my Soligor 35/3.5 lenses, even if it doesn't reach that deep into the UV.

[Cadmium]

Kind of amazed that pic was shot with the 18-55 (VR? or non-VR?) kit lens. They have the old one, then the VR, (what I have), then a newer one which has a button of some sort on the side... forget what that is for.

Also, I should not discourage you from buying anything, filter, lenses... just saying my personal opinions.

I don't sell Kuri's, never have, I have a few for back up, some I keep in hermetically sealed vibration free isolation chambers, with desiccant for safe keeping. ;)

Also I have one of the 80mm Kyoei's, and I know someone who likes that lens better for flowers, with a very short 42mm-42mm ring.

Like this one:

https://www.ebay.com...75&_sacat=0

Or is the 80mm even M42? I forget...

But I like that lens, I just hardly ever use it, I suppose because the 35mm works for everything I do usually.

By the way, the 80mm is even harder to find from my experience.

[eye4invisible]

Kind of amazed that pic was shot with the 18-55 (VR? or non-VR?) kit lens.

It's the VR version, but on a tripod with the VR off for this shot.

 

They have the old one, then the VR, (what I have), then a newer one which has a button of some sort on the side... forget what that is for.

I bought my D3200 with kit lens brand new 3 years ago, then got it converted to full spectrum a month or so afterwards. Other than the lock button, I haven't seen any kit lenses with other buttons.

 

Or is the 80mm even M42? I forget...

But I like that lens, I just hardly ever use it, I suppose because the 35mm works for everything I do usually.

By the way, the 80mm is even harder to find from my experience.

The metal EL-Nikkor 80mm I'm watching is an M39 mount. I already have an M39-M42 ring and M42-Nikon F adaptor, but no helicoids (they are on order). I'm sure I'll be outbid on it - the eBay auction closes tomorrow afternoon. That's the main reason I bought the 75mm outright - I need at least one EL, and if I win the bid on the other, it'll be nice to have a spare.

[ulf]

The metal EL-Nikkor 80mm is the best alternative.

Well worth the extra effort to get.

 

Here is a test that I think is rather accurate for some EL-nikkor lenses:

http://photographyoftheinvisibleworld.blogspot.com/2011/01/uv-el-nikkors-75mm-80mm-105mm-for-uv.html

[eye4invisible]

The metal EL-Nikkor 80mm is the best alternative.

Well worth the extra effort to get.

Yep, the 80mm would be my primary UV lens, with the 75mm as a spare.

 

Here is a test that I think is rather accurate for some EL-nikkor lenses:

http://photographyof...5mm-for-uv.html

Great blog post. The 80mm is the clear winner - virtually no aberration under UVIVF (which I haven't tried yet).

 

It looks like I need to increase my bid!

[eye4invisible]

Well worth the extra effort to get.

The good news is that I won the auction, at a bid of USD 42.50 (against only 1 other bidder, surprisingly). That seems to be a really good price for a relatively hard-to-find item, if it's in as good a condition as claimed:

https://www.ebay.com/itm/EL-Nikkor-80mm-F5-6-Enlarging-M-39-Lens-with-Front-Cap-/232808568023

 

I will post some samples here next month, once I've obtained the lens and helicoids.