Hello from Silicon Valley

[lost cat]

Hello all,

 

I'm new to ultraviolet photography. I became interested in the topic when I saw a commercial for Nivia sunscreen ala' Thomas Leveritt's "How the Sun Sees You". It happened I was trying to convince my kindergarten age son to allow me to put sunscreen on him when the ad came on - very timely! By coincidence I happened to be given a pair of Nikon D40 a couple of weeks later when both my siblings upgraded to newer Nikons. I was happy to find the D40 is one of the few cameras useable for UV work without modification.

 

Thanks to this and other UV/IR photography websites and Ebay I am now the proud owner of a small collection of UV capable lenses:

 

2 El Nikkor 105mm

3 El-Nikkor 80mm

2 El Nikkor 75mm

3 El Nikkor 50mm

 

2 Soligor 35mm f3.5 wide

1 Super Lentar 35mm f/3.5

 

I also acquired a Panasonic G5 with the 14-42 lens after seeing the lifepixel tutorial on removing the sensor filter from a G3 but I have yet to perform this modification.

 

As far as my photography expertise goes I'm an amateur. My main camera is an unmodified Canon T5i so I have been spoiled by the automatic features.

 

I currently I have the D40s set up for 3D portraits - why not? I used a standard 3" door hinge to vertically mount both cameras and used a pair of standard 1/4" x 20 flathead screws to mount the camers to the hinge. The hinge is sized perfectly as a mount for these cameras! This both places the optical paths at an appropriate interocular separation and allows me to converge the cameras on the subject. A standard 4 1/2" 1/4" 20 bolt threaded into a stacked pair of coupling nuts which allows the hinge to bolt to the tripod and to put tension on the hinge. Its a bit rickety but it works.

 

I've been using 80mm El Nikkors on a 17-31mm helicoids for portraits. I used the 105s in the past and they worked as well. A pair of 25W incandescent lamps at 1/8th second exposure works for visible images and a pair of 26W BLB CFL lamps at 1s for UV. I have found as long as the room is light controlled and there are no nearby fluorescing materials I can get decent results in the UV without additional filters.. For UV white balance I bought a 6" square sheet of virgin PFTE and cut it to cover a standard 8" x 10" picture frame. The frame both provides white balance and a fixed focal point so I don't keep having to adjust the focus. I use DigiCamControl on my laptop to remotely control the cameras. The multiple camera control is a nice way to take both images simultaneously. This setup may be interesting for 3D macrophotography as well but that is a project for a later day.

 

I have a non-photography background in optics as well. I did my Ph.D. work in applications of non-linear laser spectroscopy for chemical analysis so I have quite a bit of experience with optical equipment including high power lasers, lenses, mirrors, filters, light sources, sensors, etc. Much of that work was performed with UVA lasers. Makes me wish I had the D40 setup then...

 

I am hoping to expand my new hobby to the outdoors. Towards that end I have some questions for the group that I will post in the forums. If you have some good advice I'd appreciate it :)

[colinbm]

Welcome to UVP 'lost cat'.

I am sure you will be able to find all the help you need here & I will be looking forwards to seeing your UV pictures & particularly the 3D ones.

Cheers

Col

[OlDoinyo]

Greetings from another former spectroscopist. It looks as if you have quite the collection of gear already, and I have not seen UV stereographs before--that will be something new. A lot of us shoot outdoors, so you should feel at home here.

[Andrea B.]

Jim, hello there and welcome to UVP!

 

My apologies for missing your Intro here. (I did see the post in UV Eye Safety.) We are a small, very knowledgeable, somewhat slowly-paced little community. But eventually we get round to everything.

 

Your UV 3D work sounds like fun. Are you doing the kind of 3D which requires the glasses or the kind which requires eye-crossing? We would all enjoy seeing an example when you get a bit of time to post.

 

You have a lovely collection of UV-lenses there. And a nice setup of the double Nikons. Cool!

[A Stranger In The Wind]

Hello Lost Cat. You are no longer lost. Welcome to the forum.

[lost cat]

Hello Lost Cat. You are no longer lost. Welcome to the forum.

Thanks everyone for the warm welcomes :)

 

Jim, hello there and welcome to UVP!

 

My apologies for missing your Intro here. (I did see the post in UV Eye Safety.) We are a small, very knowledgeable, somewhat slowly-paced little community. But eventually we get round to everything.

 

Your UV 3D work sounds like fun. Are you doing the kind of 3D which requires the glasses or the kind which requires eye-crossing? We would all enjoy seeing an example when you get a bit of time to post.

 

You have a lovely collection of UV-lenses there. And a nice setup of the double Nikons. Cool!

 

So far the eye crossing kind. I have always found eye crossing easy enough to do but I am discovering other people have difficulty with it.

 

Yes, I was very lucky to get the Nikons, Even luckier given WHY. My 3yo nephew threw one off a foyer balcony to the tile floor 15 feet below. The fall broke the plastic housing and my sister presumed the camera to be dead. Our older sister and I had recently upgraded to newer, video-capable cameras so this was the enabler for my younger sister to do so as well. I asked if I could have the "dead" camera hoping to at least use it for parts. She was happy to oblige as at this point she thought it was trashed. Our older sister had also upgraded from a D40 so she was happy to "loan" that one to me along with its lens.

 

I pulled the busted D40 out, took it apart to try to fix the broken housing as best I could, put it back together, installed the lens and a battery and hoped for the best. Aside from a light leak through the still-cracked body the thing actually worked - even the flash! I bought a silicone body case to keep out as much light and dust as possible.

 

I'm still very slowly experimenting with UV, mostly because I need it to be nighttime for light control. So far I have been using the 80mm El Nikkors 1ith ~1W/m2 UV intensity at ISO 200, f/5.6, and 1s UV exposure time (1/8 Vis with two 25W incandescent lamps substituted for the 26W UV bulbs). The pictures I take in the visible are not bad but the UV ones still need work - the images look different. I don't think the problem is related to the damage since the VIS images look similar but rather in the low light levels and sensor sensitivities. Just a guess though, I'll learn more as I go along.

 

I will try taking UV images with stationary objects to iron out the hardware kinks before continuing with human subjects. I have also not done any processing of the RAW images which I should also help but I want to get the hardware optimized first.

[Andrea B.]

What are you seeing in those UV fotos that cause them to "look different"? Noise? Haze? Perhaps make a post in the Tech section and show us all what you mean because perhaps someone might have some useful advice?