Microscopes. Attaching Cameras to Microscopes. product helpsheet.

Transcription

1 G Microscopes product helpsheet Attaching Cameras to Microscopes

2 INTRODUCTION Attaching Cameras to Microscopes All modern microscopes that are designed to take cameras have a phototube in addition to any eyepiece tube(s) (typically called trinocular ). They are also expecting to take a particular type of microscopy camera called a C-Mount camera. They are not designed to take digital SLRs, Digital Compact cameras and Camcorders, indeed any type of domestic camera. It is therefore easy to obtain the appropriate adapters for c-mount cameras (called a c-mount adapter) from microscope manufacturers and the resulting images and usability are generally satisfactory. Conversely, adapters for all other types of cameras are less easy to obtain, can give less satisfactory results and are generally much more tricky to set up and use. The advice therefore is to purchase a c-mount camera designed for microscopy if at all possible. However, the natural and understandable inclination of many microscope users, especially in the amateur community with limited resources, is to wish to use the camera that they already have and with which they are familiar. This document therefore describes how to attach both c-mount cameras and domestic cameras to microscopes. C-MOUNT CAMERAS What is a C-Mount? The definition of a C-Mount is a 25.4mm (1 ) hole with a 32 TPI (turns per inch) internal female thread in the camera and a male thread on the microscope adapter. Optically a C-mount presents an image to the focal plane of the CCD at 17.5 mm beyond the shoulder of the c-mount adapter ring thread. No domestic camera has a c-mount, only microscopy cameras and some CCTV cameras have c-mounts. Note: Most CCTV cameras require a 5mm extension ring. This is because they are usually CS mount cameras and the extension ring converts a CS-mount to a C-mount. A CS mount is defined as 12.5 mm from the thread shoulder to the focal plane.

3 Connecting a C-Mount Camera to a Microscope Step 1 Identify where you wish to attach the camera to your microscope, the choices are: a) To the phototube: Typically on a microscope with a trinocular head this is, by far, the most common place to attach the camera. For this you will require a C-Mount adapter from the microscope supplier. Each microscope will have its own specific adapter, they are generally not interchangeable between microscopes because each phototube is a different diameter and presents the image at a different focal point above the phototube. The c-mount adapter simply screws into the c-mount hole on the camera. Sometimes an extension ring is required to make the image to the camera in focus as well as to the eyepieces (this is called parfocality). Some c-mount adapters have a parfocality adjustment ring built-in which extends the length of the c-mount adapter. The GX Microscopes 0.5X adapter (GXMGXD30AD0.5XADJ) has this ring: On some microscopes there is a parfocality adjustment ring built into the phototube. The GX Microscopes Trinocular Stereo Zoom (GXMXTL-101T) has this ring:

4 b)attaching c-mount cameras to the eyepiece/eyepiece tube If your microscope does not have a phototube, in other words it has a binocular or monocular head, then the only place you can attach a camera is to one of the eyepieces. To attach a c-mount camera to an eyepiece you require a specific c- mount-eyepiece adapter. These are very rare indeed. However, one exceptional camera manufacturer, Motic, with their range of Moticam cameras includes with the camera an excellent kit of accessories which includes a set of c-mount to eyepiece adapters. This means that a moticam camera can either be mounted on a phototube using a conventional c- mount adapter or to an eyepiece. The kit comprises of a 16mm lens which screws onto the camera at one end and one of the eyepiece clamps on the other end. The eyepiece clamps are the attached to the eyepiece by means of 3 centering screws. The main difficulty is that eyepieces and eyepiece tubes (in which the eyepieces are inserted) are all different sizes. The maximum diameter of eyepiece supported in the Moticam kit is 35mm. Anything larger than this is very difficult to find an adapter for and they are usually expensive. Step 2. If you want to match as close as possible the field of view you see through the eyepieces to what you want to see on the image from your camera you need to select the appropriate magnification c-mount adapter. There are generally two categories of adapters available (exactly what is available will vary from microscope to microscope). a) The most basic adapter has no glass in it, it is simply a tube of a width and length which will vary according to your microscope. This is known as a 1X c-mount adapter. Generally speaking it is the least expensive type and will present a magnified image of the centre of the field of view that you see through your eyepieces. The magnification effect is empty magnification. b) All other adapters have lenses in them to reduce the magnification effect and to try to match the field of view through the eyepiece. Typical magnification factors are determined by the size of the chip in the camera are 0.5X (most common, for 0.5inch chip cameras), 0.38X (for 0.33 inch chip cameras cheaper type of camera), 0.63X (for 0.67 inch chip cameras research grade cameras). Adapters with lenses are usually much more expensive. As a matter of fact the camera chips are not 0.5, 0.33 and 0.67 inches in size but they still are identified and classified in that way.

5 OTHER CAMERAS Connecting Domestic and semi-professional cameras to a microscope Compacts, SLRs and Camcorders As microscopes are designed to take c-mount cameras which have a uniform connection, attaching other types of cameras, which often have no mounting thread at all, is more complex and the results are less predictable. They are also frequently more vexing to use because trying to focus accurately on a LCD screen on the top of a microscope can be difficult, the setting up the camera s controls through the LCD can be equally tricky and shaking induced by pressing the shutter button at high magnifications will blur the image. As with c-mount cameras you have to first identify where you want to attach the camera: a) to the phototube GX Microscopes have specially developed a universal Digital Camera Adapter (GXMDCA) which greatly simplifies the attachment of all types of cameras. The GX Microscopes Digital Camera Adapter Kit is designed to deliver the best possible image from a microscope equipped with a trinocular head (ie has a vertical phototube) to a domestic digital camera or camcorder. To use the GXMDCA you require a 1X C-Mount adapter from your microscope manufacturer suitable for your model of microscope. A c-mount adapter is a camera adapter used to connect professional grade c-mount cameras specifically designed for microscope use. All microscopes are designed to work with this class of camera and they will give the best quality images. Example 1x C-Mount adapters are shown to the right. You also need to have a T2 mount or a filter thread of the size 25mm, 28mm or 37mm on the front of your camera. According to which size you have you then need to specify which size Filter Thread Adapter you require when ordering.

6 Filter Thread Step-Down/Step- Up Adapter. Available from camera manufacturer or photographic shop. May be necessary with some cameras to present a 25/28/37mm or T2 thread to the Filter Thread Adapter GX Microscopes Digital Camera Adapter GXMDCA Digital Camera Or Camcorder Filter Thread Spacer Tube or T-rings. Available from camera manufacturer or photographic shop. May be necessary with some cameras to present a 25/28/37mm or T2 thread to the Filter Thread Adapter GXMDCA TMA Tripod Mount Assembly Connects camera via the tripod mount and holds above optical tube assembly necessary only if no Filter Thread or T2 mount is present GXMDCA-FTA* Optional Filter Thread Adapter Connects to filter thread of camera or T2 mount available in 4 sizes: GXMDCA-FTA25 GXMDCA-FTA28 GXMDCA-FTA37 GXMDCA-T2 GXMDCA -OT Optical Tube C-mount thread bottom end, filter thread top end, with 5X relay lens inside (GXMRELAY5X) GXMDCA Digital Camera Adapter Kit Comprising: GXMDCA-OT GXMRELAY5X GXMDCA-TMA 1X C-Mount camera adapter from microscope manufacturer Microscope (any manufacturer)

7 If a T2 mount or Filter Thread is not available on your camera you can use the Tripod Mount Assembly (supplied as standard) to hold the camera in place above the Optical Tube using the tripod mount on the camera. Some cameras do not have a tripod mount and these cameras cannot be mounted on the microscope. Digital SLR cameras usually have a bayonet lens mount. To use this type of camera you should purchase the appropriate bayonet to T2 mount adapter. You may also require T-ring spacers. The adapter and spacers will be available from your camera supplier or photographic shop. Cameras with filter threads may not have one of the size threads listed above. You can purchase step-down or Step-up thread adapters from your camera supplier or photographic shop to give you a 25mm or 28mm or (preferably) 37mm thread. Shutter Release Cables GX Microscopes can also supply a shutter release cable holder to reduce shake caused by pressing a capture button. GXMDCA-SRH Attaching to Microscope Eyepiece Tubes GX Microscopes also have an adapter kit that will hold a camera above an eyepiece by clamping to the eyepiece tube. The external diameter of the widest part of the eyepiece, the external diameter of the eyepiece tube and the type of mount required (filter thread size (25/28/37mm), T2, or tripod mount) must be specified when ordering. GXMDCA-EYP Ordering information: (see diagram) For camera with no filter thread nor T2 mount but equipped with a tripod mount: Order Part: GXMDCA For camera with 25mm or 28mm or 37mm filter thread or T2 mount: Order Parts: GXMDCA plus 1 of these adapters: GXMDCA-FTA25 GXMDCA-FTA28 GXMDCA-FTA37 GXMDCA-T2

8 b) attaching domestic cameras to the eyepiece GX Microscopes supply a camera clamping device (GXMDCA-EYP) which clamps both onto the eyepiece and onto the eyepiece tube and then holds the camera in position in the same way as the GXMDCA (above). This is the same device that is supplied for use with terrestrial telescopes for wildlife photographers. Please note that because there are numerous different models of digital cameras and camcorders on the market it is not possible for GX Optical always to accurately advise which components are necessary for a particular model of camera. You should consult this guide and determine which parts you need. As this class of camera is not designed for microscopy use it is not possible to guarantee how effective the camera will be at taking pictures from the microscope, you will need to investigate the optimum set up by experimentation. If you require a camera that will give guaranteed good results from your microscope we can recommend specialist microscopy c-mount cameras. Copyright GT Vision Ltd