Taking photos of specimens
Posted 22 February 2006 - 07:11 PM
At the moment I am just using my SLR, a petri dish, and some black cardboard. Having problems with reflections, particularly off the bottom / sides of the dish.
Suggestions on how to get side shots also welcome
Oh, and it has to be a low budget solution!!
Posted 24 February 2006 - 01:57 PM
I´m in Mexico with very limited email access so I´ll send you some suggestions & tips once I get home this weekend.
Posted 01 March 2006 - 03:48 PM
Gary Cobb from nudibranch.com.au has an excellent technique for photographing nudibranchs, he sent me the details about a year or so ago but I can't find his email at the moment!
Check out some of his ID shots here using his technique with a dish and black plastic:
Posted 01 March 2006 - 04:34 PM
... Plastic inside or out? I'm having problems with reflections off the sides/ bottom of containers ... How do you light it? Any hints for getting side shots?
Anyone used an SLR adaptor for a stereo / dissecting microscope?
Posted 02 March 2006 - 09:26 PM
Okay, finally found some time to jot down some notes on macrophotography of branchs. Here’s goes....
People who shoot branchs have two main techniques. The first is to place the animal on a black background. The second is bringing a chunk of the natural substrate topside so the image includes life history information.
The same equipment is used for both techniques. It consists of a camera with a remote release on a tripod or copy stand and 2 sync’ed strobes on small tripods or the arms of the copy stand. Assorted petri dishes, small tanks, black background materials, brushes (to gently manipulate the branchs), and filtered sea water are also needed.
The small size of most branchs and the high magnification required means DOF is limited. Camera movement and vibration must be minimized as much as possible. Have the two strobes on opposite sides of the container & angled at 45 degrees to minimize reflection. You’ll still get some. I often leave one strobe in place then handhold the other in various positions to highlight different structures.
The nice flat black background you see in many images is due to having the animals on black plexiglass. I often use black cotton velveteen cloth because it completely eliminates reflection. Cut the cloth to size, soak & rinse it repeatedly to get rid of
particles & air bubbles, then place it on the bottom of the container. The animal can be put directly on the cloth, or in a small glass dish on top of the cloth in the larger glass dish - keep seawater in the larger dish so air bubbles don’t get into the cloth. The one disadvantage of the cloth is that particles will collect on it. Use filtered sea water to prevent back scatter. I also have backgrounds in other colors. Obviously a dark colored branch on a black surface will not photograph well. Neutral gray works fine for the darker ones. Remember that many of these animals are translucent or even transparent so the background color will affect their color in the image.
Glass dishes are better than plastic: they’re usually clearer & don’t scratch as easily. Some people use wait for the branch to move into view then snap away. Others use one hand to focus, one hand for the remote release, and the third hand to move the
dish to keep the branch centered... nearly forgot to mention the fourth hand which is holding one of the strobes!
There are ways to keep a branch from moving too much. Placing them on ice for a few moments will work. A solution of 7% magnesium chloride (70 grams of magnesium chloride mixed with 1 liter of fresh water) slowly dripped into the seawater is usually effective but some of the smaller or more delicate branchs will react badly. With either technique you need to carefully watch the animal to catch the moment when it stops moving and before any permanent damage is done. Don’t forget to filter the mag chloride before using it.
Photoshop - or a similar program - is also an essential piece of equipment. There’s always some distracting particles floating around unless you’re extremely patient and precise in cleaning the animal & the seawater. Limited DOF at high magnification
equals fuzzy areas on these 3-dimensional animals. With film it was always better to take the pictures at lower magnifications so the edges would be sharp then crop & enlarge. With digital - at least with the cameras I’ve used - there’s not much difference between high and low. Sometimes you just can’t get every last bit in focus. That’s when Photoshop really comes in handy. It’s easy to combine bits from two or more images to create a good sharp image.
One last simple technique to use if the rhinophores, gills, etc., aren't in focus along with the rest of the body due to limited DOF: Minimize the amount of water in the dish. The greater the depth the water the further away the ends of the appendages can be from the rest of the body. If the water is just a fraction deeper than the branch’s body the appendages will be closer to the body & more in focus.
About the photograph you posted - it’s not bad for an id shot & a first attempt. I’d be happy to have it. The only really bad bit is the area on the upper right which is burned out a bit. Overall it’s not that crisp but that might be due to camera movement. A little time with Photoshop and a new black background will sharpen it up quite nicely.
You asked about using SLR/ DSLR adaptors on scopes. That's 95% of what I do. The basic technique is the same except that TTL doesn't work through a scope so finding the right exposure takes a lot of practice if you're not a professional photographer (I'm not). DSLR really comes in handy here. Attaching the camera directly to the scope always results in unavoidable shutter vibration. Some cameras are so heavy that extra support is needed to keep the focus mechanism from slipping. The best thing to do is have the camera on a copy stand which takes care of the weight issue & minimizes movement. Scope work is one situation where film still has an advantage over digital in the crispness of the final image. I really prefer film over digital but end doing mostly digital especially in the field.
Posted 03 March 2006 - 03:28 AM
Author, Catalina Island - All you Need to Know
Posted 03 March 2006 - 03:47 AM
Author, Catalina Island - All you Need to Know
Posted 03 March 2006 - 04:00 AM
I hear you. That's why took my camera in and explained what I was doing. I tried the web approach and just ended up saying screw it, I better talk with someone.
Author, Catalina Island - All you Need to Know
Posted 03 March 2006 - 06:14 AM
Attaching a DSLR is much cheaper than a point and shoot. My photo tube is threaded at the end. All I had to do to attach my Nikon body (a film camera) was buy a C-mount adapter ring. Point and shoots require specially designed adaptors which insert into a phototube or an eyepiece tube. Cost of these adaptors is expensive, up to US $300-400. The eyepiece adaptor for my Sony F717 was $350; a second piece designed for the phototube was $100. They take focal length down the eyepiece tube into consideration and some of them have their own lenses. Martin Microscope <www.martinmicroscope.com> makes adaptors for Nikons, Sonys, and one Canon. They have supplemental information and an image gallery which are useful for beginners.
Some non-DSLR have small diameter lenses which can be just held next to the scope eyepiece. You can get some surprisingly good pictures this way. The down side is that there might be vignetting or worse, scratches on one lens or the other. For these it's best to have them on a tripod or copy stand & positioned a few milimeters off the lens. Use black paper & roll it into a tube which extends over both the lens & the eyepiece to eliminate extra light leaking in; tape or rubber band both ends. Which reminds me - whenever you attach a camera to one eyepiece always cover the other eyepiece with cloth or a tube when you're ready to click the shutter. If not you may get images of overhead lighting leaking through the other eyepiece. Took me a while to figure that the strange rectangular blur in my first attempts was the ceiling fluorescent!
As I said TTL doesn't work on a microscope (or telescope, thanks Joe). Your strobes will not be controlled by the internal exposure meter. You can get excellent shots using normal microscope lights instead of strobes by allowing the internal meter to determine exposure as long as there's no external sources of vibration. These shots will be long - up to several seconds depending on the light source. A bouncy floor, a nearby door closing, an overhead fan moving the seawater, someone walking by or sharing the work table - these will all cause vibration and blur the image. Some colleagues of mine have work tables made of concrete, wood, & tile - no nasty vibration there! I always get great shots using these.
Use the microscope for magnification not your camera. If your camera has digital zoom don't use it. Scope images at high resolution become pixellated anyway; using the digital zoom just increases the pixellation. Use the camera's regular zoom just enough to eliminate any vignetting in the image (although this is unavoidable with some cameras).
My favorite web sites on macro- and microphotograpy are <www.macrophotography.com> and <http://www.microscopy-uk.org.uk/>. You'll find lots of great information as well as stunning images.
Posted 03 June 2006 - 02:33 AM
2 external strobes (handheld from the sides), a DSLR (Canon 20D) on a microscope stand, 60 mm macro lens.
The torchlight was to provide some light for manual focusing...
Black cloth was used underneath a glass petri dish.
MgCl was sometimes used to anaesthetize.
Photos were taken on a vibrating ship at F16, 1/250s.
Most photos, all shot in Raw, turned out well using this setup.
Sometimes I've raised the petri dish so as to have 5 cm empty space below
- with the low DOF nothing underneath the speciment will be in focus, which can give some good results as well.
Posted 09 June 2006 - 05:40 AM