Archive for category UV

Lenses I am trying to use for UV on a Canon EOS 600D full spectrum and Baader U

I need a reference place to store my feedback on various lenses I have tried for UV photography.
I do not have access to any kind of spectrum analysis so this is my real world playing about.

My setup: Canon EOS 600D (Canon EOS REBEL T3i) with full spectrum modification by Ehab Eassa  (Eassa on eBay) Using a Quartz Spectrosil replacement for the removed IR/UV block filter.

Microlenses still in place. (Removing these renders the camera incapable of colour but improves contrast. It turns it into a UV only camera, not full spectrum).

Sensor cleaning mechanism removed.

Pros of this camera : Appears that the Sensor is UV sensitive and the fold out display with Live view is excellent.
Cons of this camera : cheap and nasty plastic design unlike the more professional series. (also a pro, as you can modify and obtain the camera cheaply).

Full spectrum Canon camera setup for UV (UV Gear)

You can see some of my UV photos here https://www.flickr.com/photos/mickyj_photos/sets/72157631805070468/

Canon Lenses

Canon EF L series 24-70 mm with step up/down rings and a BaaderU filter (1.25″) on the end – needs a high ISO and long exposure time. Not suitable for anything that moves. Not enough light for Autofocus to work. Nice images but frustrating to use. Click through to the photos for more details.

Canon L with Baader U (UV)

Baader U on Standard Lens

 

Canon EF 50,, 1.8 mm lens with step down rings and Baader U filter. ISO 800 and 1/13 sec exposure works well. Might be good for Video. Autofocus in UV range works. Native EF mount is a bonus. Cheap nifty 50 lens. Well worth playing with as it causes the least frustration and messing about. It is cheap so within reach of most people. Works well showing sunscreen response, not as good showing flower patterns. I need to do a video with this one.

UV Suncream Test (UV)

Canon FD 50mm 1.l4 with adaptor for EF mount – not yet tried

E.Rokker

Minolta E.Rokkor 50mm f4.5 Enlarging Lenses, M39 Mount – No idea just yet. Just ordered this and will know soon.

Minolta E.Rokkor 75mm f4.5 Enlarging Lenses, M39 Mount – No idea just yet. Just ordered this and will know soon.

Helios
Helios 44-2 2/58 Russian USSR lens M42  Zenit 1979 – preset. This lens is a preset lens which gives it two aperture rings. An Aperture lock ring and a smooth (no click) manual aperture ring. Great for Video. Yet to try UV.

Normal spectrum photo

Helios Lens Experiment 1 (100% crop)

 

Nikon EL Nikkor

Nikon 1:4 50mm El-Nikkor Enlarger Lens f=50 – works ok on UV. Need to be close to the subject. Need a M39 Screw Mount to EF adaptor and I use a Bellows to get focus. Step up/down rings to fit Baader U. 75mm is better.
Nikon EL-Nikkor 75mm f/4 Enlarging Lens – works ok on UV. Need to be close to the subject. Need a M39 Screw Mount to EF adaptor and I use a Bellows to get focus. Step up/down rings to fit Baader U. Most of my UV photos in the flickr set that involve flowers were done with this lens.

NIKON EL-NIKKOR 80MM 5.6 PROFESSIONAL ENLARGER LENS – works ok on UV. Need to be close to the subject. Need a M39 Screw Mount to EF adaptor and I use a Bellows to get focus. Step up/down rings to fit Baader U. 75 mm is better.

Optomax (Pentax)

Optomax 35mm f/3.5 – You have to stand too far from the subject, the UV response is bad and focus is hard to achieve. It is a wider lens than my EL Nikkor so it does have it’s place.

Flowers in UV (UV)

 

Jena (Zeiss)

Jena Aus 135 (Zebra) (see the Flickr image for more information)

UV Lens test - Jena Aus 135 (Zebra)

Jena Carl zeiss sonnar 4 135 (see the Flickr image for more information)

UV Tests, Jena Carl zeiss sonnar 4 135

Jena Carl zeiss sonnar 4 135 (see the Flickr image for more information)

UV Tests, Jena Carl zeiss sonnar 4 135

Jena DDR Aus T 2.8 -50 (see the Flickr image for more information)

UV Lens test, Jena DDR Aus T 2.8 -50

UV Lens test, Jena DDR Aus T 2.8 -50

Jena flektogon 2.8 – 35 (see the Flickr image for more information)

UV test lens, Jena flektogon 2.8 - 35

UV test lens, Jena flektogon 2.8 - 35

 

 

 

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Sun damage, sunscreen, UV and photos

I have been playing with UV photography on a Full spectrum Canon EOS 600D (Canon EOS REBEL T3i) for some time. I wanted to see the UV markings on flowers that some animals / insects etc can see.

I discovered a world where paint patch ups, metal alloys and many other things also look unique and different when viewed in UV.

Early on I tried a sunscreen experiment where I painted half of a subjects face and then filmed the person, hoping to see the blocked UV. I was unimpressed. It caused a greyish hue or cast over the face, but nothing with any real impact.

 

Then, a little later,   Thomas leveritt posted a Sunscreen video on Youtube. I have been trying to replicate it ever since.

I figured that Thomas leveritt may have had more than a full spectrum conversion done to his camera. Maybe they also removed the Micro filters ? Perhaps he is using a quartz lens ?

Finally, I have similar results. Thanks to Antoni Łoskot for pushing me hard to find a solution. It turns out that with a Canon 50 mm 1.8 EF canon lens, I can get the same results.

UV Suncream Test (UV)

My understanding with UV has been turned on it’s head or maybe, Canon cheap lenses are *real* cheap.

I have been acquiring old lenses. lenses that are manual focus, with as few glass elements as able, before UV blocking multi coatings came into fashion. Lenses that need EF adaptors and limited to a specific focal range. I have then been adjusting the lens to move focus into the UV spectrum, from the Visual spectrum. Tedious and painful.

All of this so I can reduce ISO to 400 and time to 1/25 sec. But .. am I looking at this wrong ?

Maybe with the sunscreen video, you can have a higher ISO and slow shutter time as the subject is moving and you do not notice ? Maybe I am looking for a UV response in the spectrum too low ? Does sunscreen react at a higher wave length ?

so, using a Canon EF 50mm 1.8 lens with a 52 mm to 1.25 ” adaptor and Baader U filter, I get the results I need.

1/13 sec and ISO 800 looks a little blurry for a still shot but the Sunscreen is a black colour, not grey. This is what I want. Finally, the results I wanted !!!

I will have to test further but maybe my EL Nikkor lenses will work better for flowers ?

I have to use my EL nikkor with a bellows to get focus. With the canon EOS and EF lens config, I get Auto focus in the UV range !!! Awesome. Less fiddly.

I have tried a Canon L 24-70 mm and I needed ISO 3200 at 3-4 seconds to get any UV response. Maybe the difference of L professional series to “kit” cheap lens ?

Regardless, I am happy it works.

My Full spectrum mod was done by eeassa (Ehab) on eBay. I love it !!!

 

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UV Video with a modified DSLR (Preparing to look at skin with sun damage)

Recently there has been a huge interest in my YouTube post using a normal Canon EOS 600D camera and converting it to Full spectrum, then blocking all but UV.
Many enquirers want to find a cheap way to convert a camera and then show how skin is damaged by the sun and how Sun cream blocks the UV Radiation.

There has been so much interest that I thought I would blog about it.

(Example video at the end of this blog)

Firstly, be careful with UV as it is dangerous. My preference is to take photos (and now video) under normal Sunlight.
This obviously rules out indoor photography.

If you modify flashes, install overhead UV lighting (even LED UV lights) be aware you are likely subjecting your model to cancer causing levels of UV.
They should be wearing sunglasses and sun cream (Which is not productive for this kind of work).

You really need full sun direct onto your subject.

Unless you purchase a purpose built UV band pass camera with expensive Quartz lenses, you are going to need to buy various items, have them modified and manually assemble.

There are 2 types of camera modifications I will mention.

  • Converting a camera to Full spectrum
  • Converting a camera to UV only

I have elected to convert my camera to full spectrum as it is cheaper and more useful for other types of photography.
As per my YouTube video (https://www.youtube.com/watch?v=UrvViq2Y7OE), this means someone modified the camera. They open the camera up, remove parts and filters.

Modern cameras are designed to block UV and Infrared. They are built to restrict the captured light to that same light we can naturally see with our eyes. We need to undo all this.
The camera’s sensor is able to see much lower and higher in bandwidth than our eyes.
Once the camera is full spectrum, the sensor is opened up to its full range including the visual spectrum.

This is the first step, modifying the body. The next step is lens selection and UV band pass filters.
If you want contact details for this body modification, I will pass along details for Ehab Eassa whom I have do my work. He can also modify point and shoot cameras.

I have a Canon EOS 600D converted to full spectrum. Many debate that Nikon is better for UV as it is more sensitive but with recent cameras, I think it makes little difference.

If you elect to go to the trouble of converting a camera to UV only (the other option), the final UV image is much crisper. It is a far more expensive process.
It is more rewarding as the images are in greyscale (avoiding the distraction of the pinkish colour from Full spectrum conversions) and the detail is far better with better contrast.
This is because a professional has removed the micro lenses from the sensor. The Micro Lenses are responsible for breaking the detected image up into the colours that will produce a colour image.
They make images colourful but reduce contrast. Removing these mean the sensor can only work with image data in its native format, black and white.
I have contacts that can sell you a camera with this already done to it.

Lenses

Now, you have your next battle. Lenses.
Since the mid 1980’s, almost all lenses have a multicoating on it to stop light bouncing around inside the lens body causing flaring. It also reduces UV. This coating is on the front of the glass.
The other problem is glass. The more glass elements that are in the lens, the more that UV is reduced.
The more that UV is reduced, the longer your exposure needs to be and the higher the ISO to get an image.
I can’t buy any lenses made for my canon body that will not block UV. All lenses do.
My choices are

  • Take a perfectly good lens and try and buff/scratch the UV multicoating off (The works but will reduce final image contrast).
  • Buy an old lens and fit it with adapters.
  • By a real UV lens made of quartz (Rare and very expensive). Nikon made one for a while.

I have gone with the second option. I have purchased old Enlarger lenses. These lenses are from the film days, used by film developers to expose film, to give you your little packet of photos.
They shine a light through the negative, through this lens, onto the final piece of film.
These lenses needed to be very faithful in reproducing the negative. They have no UV coatings and very few lens elements. They are at limited focal lengths.
I am using the EL Nikkor series of enlarger lenses, purchased from eBay.

I then have an adaptor to mount it to my canon mount.

As the lenses are not for Canon, the focal plane is not aligned with the correct focal distance so I use a bellows to get focus.

Filters

Now comes the easy part. You need a Bad pass filter for UV. This blocks all but UV. There is no visible light or IR leaking through my filter. Only UV. Even holding the lens to the sun, I can’t see through it.
I opted to buy a telescope accessory and some step up/step down rings to make it fit my lens. I have a BaaderU filter.

Now, you need to put it all together and can start looking at Video. at this point, this excersie will have easily cost over $1000 AUS/USD.

Video

I note that in live view mode whilst talking a photo, I get a nice clean 720p video image, if I made the ISO high (6400), the shutter slow 8” and manually focus and set the lens to F4 or less (There is no electronic control of the lens settings).
The only issues are the sun reflecting off the live view screen made it hard to view and in live view and if you are not actively taking photos, it shuts off quickly.

In video mode, all the settings are Auto and I can’t see anything at all.
By setting the video mode to manual, I can control the ISO and the video format. I was able to record in 1080p. I also set the style to greyscale.

I now need to concentrate more on focus and use a tripod (You can zoom in in live view to check your focus).

Further experimentation

My other options I have yet to play with are Magic Lantern and recording from live view mode in 720p.

Here are the next steps to explore

Capture 720P HD With Any LiveView Capable Canon Camera
http://www.diyphotography.net/capture-720p-hd-with-any-liveview-capabale-canon-camera/

The Canon 600D is supported by magic lantern and has some additional video control
http://www.magiclantern.fm/downloads.html
I will note that my sensor is not sensitive enough for high frame rate however, given the budget I am working with, the result is quite good.

Here is an example of what my setup can produce
http://youtu.be/jO8Fb6VhZ1E

 

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