15 replies to this topic

[Ockertfc]

Hello All,

I hope this is the correct area to post this.
I am a complete newbie when it comes to UV photography.
Below I post some items I am looking to purchase.

My main question is can I with a reasonable expectation of success achieve photos such as in the images below with the equipment I list?
Advice would be greatly appreciated.

My goal is to capture images in the UV range from flowers in the greenhouse and field.
On the images below I circled examples of what I am aiming for.




This is the setup I am thinking about:

UV-VIS-IR camera
Pancake Lens
52 mm to 58 mm Step up ring
330 nm Filter
Band Pass Filter 320 - 670 nm
UV Flash

Given the above equipment can I reasonably expect to achieve images such as above?
Should I be looking at specific software? We run on windows systems, ideally required software will work on PC.

Looking at my goals above, what is your number one recommended thread to read from this forum?

[Andy Perrin]

It will do! I would have put it in the Techniques, Tests, and Gear Talk section to be honest, but this is good enough.
https://www.ultravio...ests-gear-talk/

To the equipment!

Camera: fine
Lens: a pancake lens at 40mm is adequate but if you are shooting flower photos, a 105mm EL-Nikkor might be better? I would look on eBay...
That UV filter will probably have dichroic artifacts on a 40mm lens. Also it looks way overpriced. Why not get one of Cadmium (UVIR Optic's) stacks? Or a Baader U if you want dichroic?
That band pass filter is unknown to me, but again, why not just get 2mm S8612?
The flash will work but you could also convert your own if you have one lying around. It's not that hard.

Basically my feeling is that you are probably paying too much for all this when there are cheaper alternatives that would be better. I think the proposed rig would work, but it's very far from optimal in performance as well as price.

Edited by Andy Perrin, 13 January 2021 - 05:24.

[Cadmium]

For the yellow visual shot you need:
Bluer < S8612/BG39 - BG40 - BG38 - Baader UV/IR-Cut > Redder (personally I use BG38, most used BG40, but not all visual filters work the same with all full spectrum cameras).
For the black and white (assuming those are reflected UVA and not desaturated UV+Blue+Green) use U-360 2mm + S8612 2mm stacked (screwed together).
If you use U-330, that is UV+Blue+Green = 'bee vision', it is UV+some visual, U-330 1.5mm + S8612 2mm stacked.
My advice, get these three filters,
1) U-360 2mm thick
2) U-330 1.5mm thick
3) S8612 2mm thick.

U-360 2mm + S8612 for reflected UVA
U-330 2mm + S8612 2mm for UV+Blue+Green (bee vision)
S8612 - visual (but you might want BG40 eventually?)
U-360 alone = dualband IR = Blue skies with white foliage out of camera.
U-330 alone, also dualband, but not as cool as U-360 alone (IMO).

You can use S9612 for visual, but I can't say how visually accurate it will look with your camera.
I have no experience with your lens, but the lens is very important for UV, some are good some are not.
It is best if your camera has live view.
If your lens/camera will accept 52mm filters then that would be more readily available.
For either reflected UVA or UV+Blue+Green you don't need to filter your flash, but the flash needs to be modified to full spectrum and it needs to be a flash that will emit good UVA when once modified, ask around.
Let me know if you have any questions.

Edited by Cadmium, 13 January 2021 - 06:26.

[StephanN]

Andy Perrin, on 13 January 2021 - 05:23, said:

Lens: a pancake lens at 40mm is adequate but if you are shooting flower photos, a 105mm EL-Nikkor might be better? I would look on eBay...

Agree 100%. Check out the sticky list for lenses and try to find a nice one on EBay. For the price of the pancake you'll probably be able to get a nice EL-Nikkor (105 or 80 mm), one or two focus helicoids, and perhaps even second lens. I know you mentioned flowers, but 35mm-lenses suitable for UV are abundant, again, check the sticky list, and a few members around here are also taking quite nice photos of landscapes with such lenses; also if you want to take photos of a bunch of flowers, a shorter focal length might come in handy.

[UlfW]

Cadmium, on 13 January 2021 - 06:21, said:

U-330 2mm + S8612 2mm for UV+Blue+Green (bee vision)
S8612 - visual (but you might want BG40 eventually?)
U-360 alone = dualband IR = Blue skies with white foliage out of camera.
U-330 alone, also dualband, but not as cool as U-360 alone (IMO).

You can use S9612 for visual, but I can't say how visually accurate it will look with your camera.
I have no experience with your lens, but the lens is very important for UV, some are good some are not.

Steve, just a few typos to correct above that I marked bold underlined

[dabateman]

What is your budget?

Is this for personal use or a lab were you need to order directly from one seller with an order number?

Answers to these questions will help direct our comments.

As you can order that lens and a Baader venus U filter (better filter and cheaper) from B&H photo with the step down ring (a 52mm down to 48mm) you would need for the Baader.

[UlfW]

The UV-reach of the EF 40mm f/2.8 is not that good either.
This is a comparison of the UV-transmission between the EF 40 (red) and the El-Nikkor 80 old metal enlarger lens (black) :

As the peak transmission for normal UV-pass filters is located around 365nm and the transmission is very low close to 400nm the high transmission of the EF-lens close to 400nm is not utilized.

The statement by Maxmax " This Canon lens works well for UV photography to about 340nm. is wildly exaggerated. At 340nm this lens transmit less than 1%. At least that is true for my copy, measured properly with a spectrometer setup.
You need at least 20-30% transmission to get a meaningful exposure time.

You will still get the type of images you are aiming at, but the EF 40mm is not optimal for that

Edited by UlfW, 13 January 2021 - 09:39.

[dabateman]

Ulf,
I don't know why but they have selected an AF lens. That might be a requirement, I don't know. Also the EL can't be purchased new with a PO number or whatever their institution uses if this is for research use.

However, look at your plot. The area under the 40mm is much greater in the 372nm to 395nm range than the EL80. There will be significantly more outside UV in the field and even in green houses in that range where this equipment will be used. So actually your plot indicates that the Canon 40mm is better.
Use a Baader venus u filter or Straight edge u gen3, or 2mm U360/2mm S8612 stack and the Canon will be better outside in the field.

Also why a Canon?
A stock off the shelf Olympus Em5mk2 can also work with the filters I just mentioned. But then a Sigma 30mm f2.8 art lens would be good, if need auto focus.

Many also have great success with a Sony A6000. So there are many options. Just depends on what camera you want to use or like to hold onto for hours.

My recently Kolari converted Em5mk2 can see to 300nm and has less noise and hair sharper than my Em1mk1 camera, at 300nm. But there you will need a quartz lens.

[UlfW]

David,
You are right.
I missed reading the usage conditions.

Still both the Baader U and 2mm U360/2mm S8612 stack limits the transmission very much in the upper band.

A Straight edge u gen3, a MoonU or even a S8612, 2mm / UG2A, 2mm-stack would be better filter alternatives.
The last pair has a small bit of transmission beyond 400nm.
However it is very difficult to tell the difference between light at 395nm and 405nm and the 395nm will dominate completely.

A S8612, 2mm / UG2A, 2mm-stack still gives pitch black UV-signatures when such are present.
Flowers with a higher reflectivity closer to 400nm, often white flowers will be rendered in blue colours instead of the purple you normally get from Baader U or a 2mm U360/2mm S8612 stack.

[Andrea B.]

Ockertfc - Please do also read through this <> Sticky :: UV Photography: Cams, Mods, Lights, Links <>

Also please look at the UV-pass filter section in <> Sticky :: UV/Vis/IR Filters <>

To make the reflected UV photos shown in your example you do not want to use a 330 nm filter.
Look instead for a filter or filter stack peaking around 360 nm for faster and better exposures.
The UV-pass choices explained in the Filters sticky are, in summary:
BaaderU, KolariU, U-360 + S8612 stack, UG11 + S8612 stack, StraightEdgeU.
Look in the sticky for links.

My personal experience with converted cameras is that Sony A, Sony Nex and Panasonic Lumix
are the most versatile choices and best for in-camera white balance and good image quality.

[dabateman]

Andrea,
The filter that is being discussed is the Xnite 330, not the Hoya U330 filter. The Xnite has IR leak and will not be the best for floral subjects. But its like the Hoya 340 filter as I think that might be its base, but I don't know.
*****

I would recommend the Baader venus u filter for floral subjects. Really the best, and you are suggesting a 60mm equivalent lens. So the dichoic nature of the filter will not be a problem. If you want to use lenses wider than 50mm equivalent (135 format) then the U360/S8612 stack will be better.

I have used Sigma, Kodak SLR/n, Canon, Nikon, Panasonic and Olympus cameras. From my experience the Olympus is the easiest to white balance in multi spectrum. Olympus is the only cameras with widest manual white balance entry, spaning 2000 to 14000. All other cameras seem to only offer 2500 to 10000. That limits IR at 2300, whit I like and UVB at 14000, which I need a little more.

[Andrea B.]

(David, I removed the U.)

Unfortunately, the BaaderU is becoming prohibitively expensive.

The Olys are good for WB, but I don't like the IQ when you start using ISO-400 and beyond. Just a personal preference though. And actually one of my fave cams for conversion, the Lumix G line, does not have such great IQ either at higher ISOs altho newer G models have improved. (Exception for the S line which are superb for IQ.)
Given a choice between Canon and Sony, I'd go Sony for the superb image quality. Again just a personal thing as I don't like to have to process against noise.

Question: How do you know the white balance spans 2000 - 14000? Just curious how to find that.

[Andrea B.]

Added: Ulf's chart certainly does tell the tale of that lens.
And I must add that if the lens cannot transmit at 330 nm, then you really really do not want to use a 330 or 340 nm UV-pass filter !!!!

For that Canon 40mm pancake lens the very best choice is the current 3rd generation StraightEdge U.
You would get the floral photos you want with that combo.

[dabateman]

Andrea B., on 13 January 2021 - 19:07, said:

Question: How do you know the white balance spans 2000 - 14000? Just curious how to find that.

On the Olympus in CWB, the custom white balance section you can dial it in.
But most cameras will indicate the custom range in the manual. I don't know why Olympus is the only camera to have such a broad range. But I love it. I typically use 2300 or 2250 for IR. A lot of my bulbs are 3200, and UVB needs at least 14000. 20000 would be even better.

[Andrea B.]

For the Nikons I've used, you can select a K setting between 2500 - 10000. But in most (but not all) converters the raw Nikon file itself can be adjusted between 2000 - 15000. So it is kind of strange that white balance under a UV filter cannot be obtained in-camera for the Nikon DSLRs when the files take such an adjustment quite well outside the camera.
Point being, there seems to be a camera range and a file range which might not be the same.

These days I just shoot UV in any camera using the Monochrome setting because I can get the optimal exposure that way by "pushing" the JPG histogram towards the middle. Also in Mono you can see quite well the details of what you are shooting. Later during conversion I can decide how best to bring out UV false colors. I do not know *why* I didn't figure out this Monochrome way of shooting UV from the get-go. If you nail the lights & darks of our strange reflected UV photos, then the false colors usually come out well too.

Of course, everyone's mileage may vary on this Mono UV shooting style. But, it's all good!

[Andy Perrin]

My Sonys white balance in the camera just fine, so I usually do that when shooting UV reflectance or most things really. Usually on PTFE or just the road.