Uv flower tips

[Namestom]

Any tips on photographing flowers with a 365nm uv led light inside? They come out pink rather than mostly black

[dabateman]

Can you upload a photo to show the issue?

 

Are you doing UV reflectance or UV fluorescence?

Is you light source in the flower or shinning on the flower?

What filters are you using on your camera lens?

What camera, converted or stock?

What lens, a quartz lens or uv permissive or stock lens?

What is your light source, a filtered convoy flashlight or flash?

 

With these answers I can help you. Could also be your White balance is off.

 

[Stefano]

Could also be your White balance is off.

That's what I thought too. Maybe this isn't your problem, but if you want yellows and blue-violets in your images you have to white balance them. Your sensor will simply record different shades of pink-magenta, and to make them appear you have to do a white balance (if you have PTFE, that's the ideal target, otherwise you can do that on a white paper tissue, which works quite well for me).

[Stefano]

Are you sure that your flower is supposed to look black?

[nfoto]

The basic question is: what flower?? That determines the main range of possible answers.

 

Start by posting close-ups and details of the flower under visible light, unless you are certain already of its identity.

[ulf]

With an UV-LED as light source there will not be much colour ad the LEDs spectral bandwidth is small.

[Namestom]

I use the canon kit lens 18-55mm. I stack ug11 and s8612. I get plenty of light transmission. I'm looking for tips, as my flower photos didnt come out well using a 365nm light. I didnt upload any yet, but I will try out a few in sunlight. I have a marigold, daffodil, and daisy gerbera. I can purchase another flower, if suggested.

[Stefano]

I use the canon kit lens 18-55mm. I stack ug11 and s8612.

Thicknesses?

[ulf]

Canon have several 18-55mm zooms.

All of them are quite complex with many lens elements and coated lens surfaces.

That normally hamper the UV-transmission dramatically.

 

This is an example of one of the 18-55mm zooms :http://www.eflens.co...8~55_35-56.html

 

I do not think the transmission of any of them is especially good at wavelengths emitted from a 365nm UV-LED.

That can explain your poor results.

Outdoors in bright sunlight you might get some slightly better result, but for more real UV-photography a lens more suited for this is recommended.

[Namestom]

Both filters are 2mm thick. Any recommendations for a better ef lens? I cant afford much. I have nothing to compare the lens to, but it doesn't seem to block much UV.

[Stefano]

Both filters are 2mm thick.

You have OD 5.227 at 693-694 nm, which is very strong, so you should be leak-proof. IR isn't a problem.

[Namestom]

I have the canon 24mm also which might work better. I'm not too knowledgeable about lenses. A quick search here came up with the cassar s 50mm. Looks like I could snag a tower 51 camera that has this lens for cheap. Would this work?

[dabateman]

I have the canon 24mm also which might work better. I'm not too knowledgeable about lenses. A quick search here came up with the cassar s 50mm. Looks like I could snag a tower 51 camera that has this lens for cheap. Would this work?

 

Please upload an image before we jump all over your lens choices. Its possible that you are very lucky and you may be getting some 380nm through that kit lens. I know I get 380nm through the complex Olympus 14-42mm R2 kit lenses. Just have longer exposure times.

If real UG11, you have a great filter set.

Go out side and take a photo.

If you want a control flower, then a Sunflower seems to be well known. But your Daffodil will work.

 

Should look like this:

https://www.ultravioletphotography.com/content/index.php/topic/2183-narcissus-sp-daffodil/page__hl__daffodil__fromsearch__1

 

Is your canon full spectrum converted?

 

After we see a photo with your cammera exposure settings and your White balance settings. Then we jump to lens or full spectrum camera choice.

 

Is your 24mm a STM lens?

A user here reported that it was good for UV. About 1 to 2 stops less than the excellent Canon 40mm f2.8 STM lens.

If you are looking for an excellent Autofocus cheap Canon lens. Then I would recommend the 40mm STM. It takes 52mm filters, AF in UV and can be purchased cheap used. I got mine for $70.

[Cadmium]

Use sunshine for you light. 365nm light is used for visual fluorescence, it is very narrow band UV light, so you will get pretty much black & white with as little blue looking violet.

If you want to shoot indoor, then use a full spectrum flash, or some kind of wider range UV source, even most common black lights have wider range UVA than a 356nm torch.

The only thing I might use a torch for with reflected UV photography is maybe to help focus, but not for illumination.

Sunshine rocks.

[SteveE]

Looks like I could snag a tower 51 camera that has this lens for cheap.

You have to be careful. A lot of the rangefinder style cameras with Cassar S lenses have the lens permanently built into the camera body and are not removable. These cameras are generally relatively inexpensive, but unless you are a machinist, you are not going to be able to use the lens on something else. Several of the Tower 50mm Cassar S cameras that I can see currently on eBay look to me to be of this type. Unless it is clear from the listing, you should ask the seller if the lens is removable (and what mount it uses) for this sort of camera. I made this mistake myself the first Cassar S that I bought on eBay.

[photoni]

i just saw a great photo of a gerbera !

www.flickr.com/photos/160246804@N08/49302652593

[Andrea B.]

Namestom, here's some practical advice for using a UV-LED torch indoors.

BTW, I am assuming two things:

• that your camera is converted, and
  
• that you want to make a reflected UV photograph and not a fluorescence photo.
  

If that isn't the case, then stop here.

 

Practical Advice

Well, I hope it is good, practical advice.

• Camera on tripod.
  
• Remote shutter release desireable.
  
• Shoot raw in black & white mode. (Color can be restored later.)
  
• Aperture f/5.6 -f/8 to begin. (Let the UV light in.)
  
• ISO-800 to begin. (Boost the signal but not too much to keep noise down.)
  
• Long exposure.
  
• Paint the flower with UV-LED light.
  

A long exposure will be needed indoors when using a UV-LED. You will have to experiment with exposure lengths. Start with 1", 2", 3" etc. until you find the exposure length which is long enough for you to paint the flower with the UV-LED several times over while the shutter is open. When you review the shot, you should be able to make out surface details on the flower petals and see the flower structure. Expose your shot long enough that the black & white histogram is centered or at least not sitting against the left-hand wall.

 

This painting method is used by most of us indoors when using a UV-LED torch. It does take a bit of practice, but will definitely work assuming a reasonably UV-capable lens.

 

When you convert the raw photo the color will re-appear and usually be a red/magenta mess. Click on anything pinkish/magenta with your converter's white balance tool. That should give you a good basic conversion to the blue/yellow/grey/white/black standardized UV color palette.

 

Narcissus/Jonquil/Daffodil and Gerberas are usually UV-absorbing.

Examples:

Narcissus

Daffodil

Narcissus

Gerbera

 

Recommended Beginner Flower: Sunflower

You can usually find Sunflowers for sale at a grocery store or florist. The Sunflower typically has a UV-dark center with some UV-bright ray (petal) tips. This known UV pattern is useful for testing how well camera/lens/filter/UV-LED are working.

[ulf]

Also be prepared on that there will not be much different colours as an UV-LED torch emmitt a less wide colour spectrum than the sun or an UV-converted flash.

[Andrea B.]

that definitely depends on the flower.

 

example of UV-LED painted sunflower here:

https://www.ultravio...mmon-sunflower/

 

EDIT: I had a bad link here. It has been fixed.

The sunflower in the third (3rd) photo was illuminated by UV-LED and exhibits false yellow and bits of false blue. Thus it is a good example to show that you do not always get a restricted false colour palette under UV-LED. Sometimes you do, occasionally you do not.

[photoni]

in another post I put an example of a Van Gogh Sunflower seen from photographic emulsion with collodion

[ulf]

that definitely depends on the flower.

 

example of UV-LED painted sunflower here: www.ultravioletphotography.com/content/index.php/topic/2189-narcissus-%e2%9c%bd-%e2%9c%be-%e2%9c%bf-%e2%9d%80-%e2%9d%81-%e2%9d%83/

That is very true for UVIVF, but not for UV-photography that I thought was the reason for the question.

Here is an example of this:

https://www.ultravioletphotography.com/content/index.php/topic/2921-in-the-spotlight/page__hl__convoy__fromsearch__1

Except for the first image the main illumination of the flower is from an UV-LED

[Andrea B.]

My link was bad in my Post #19. Perhaps the correct link and added comment there will clarify what I was trying to show.

https://www.ultravioletphotography.com/content/index.php/topic/3757-uv-flower-tips/page__view__findpost__p__43807