PiggyBack – This method simply uses the telescope as a tracking platform. The camera is mounted to the top of the telescope tube using a “Piggyback Camera Mount” and shoots through it’s own standard camera lens. This method does not offer any gain in magnification or light grasp over what your camera lens provides, it simply allows the camera to follow the sky so long exposures do not streak as the earth moves.
See:
We do not currently carry any Piggyback mounts, consult your telescope manufacturer for an appropriate mount as they are typically made to fit a particular scope model.
Prime Focus – This is the purest form in that it uses the telescope as the camera lens. The camera is not fitted with a lens and the telescope is not fitted with an eyepiece. The camera film plane (or CCD) is placed at the “prime” focal point of the telescope. This method offers the widest, brightest fields, moderate magnification and shortest exposure times. Typically used for imaging nebulae, galaxies and other large deep sky objects. To use this method your camera must have a removable lens (SLR/DSLR/CCD Imagers/Some Webcams). This rules out most all point & shoot type consumer cameras (for these see “Afocal” below).
See:
1.25” Prime Focus Kits (for scopes that accept only 1.25” eyepieces)
2” TRUE-2 UltraWide Adapters (for scopes that can accept 2” eyepieces)
C Mount Adapters (for box type cameras)
Webcam Adapters (for many popular webcams)
Barlow Projection – This method is essentially the same as “Prime Focus” above except that it places a telenegative lens (barlow) between the telescope and camera. This increases the focal length of the system which increases magnification.
See:
1.25” Prime Focus Kits (for scopes that accept only 1.25” eyepieces)
2” TRUE-2 UltraWide Adapters (for scopes that can accept 2” eyepieces)
C Mount Adapters (for box type cameras)
Webcam Adapters (for many popular webcams)
Eyepiece Projection & Variable Projection – This method also requires a camera with a removable lens so it is typically limited to SLRs/DSLRs/CCD Imagers. The camera body is fitted to an eyepiece which is placed in the optical train between the camera and telescope. The eyepiece “projects” the image onto the film plane (or CCD). This provides a method of increasing the magnification just as it does visually. Shorter focal length eyepieces provide higher magnification. Often rather simple eyepiece designs work best for this purpose. A “Variable” projection adapter allows you to adjust the distance between the film plane (or CCD) and the eyepiece. This varies the magnification of the system allowing you more flexibility in adjusting the image size when framing your shots. Typically used for Lunar & Planetary imaging where higher magnification is needed to bring out detail.
See:
Eyepiece Projection Kits
Variable Projection Kits
VariMax (Large) Projection Adapter
AdaptaView Adapter (fits many TeleVue eyepieces)
Afocal – This method is primarily employed with consumer “point & shoot” type cameras. Since these cameras do not have a removable lens they MUST shoot through an eyepiece to form an image. If you were to try to shoot through a scope without an eyepiece you would simply get a picture of the inside of the scope. Care should be used in eyepiece selection for this method since trying to shoot through an eyepiece with a small lens and/or short eye relief will result in a lot of vignetting. Vignetting is when the image has dark corners or a dark circle surrounding it. Minor vignetting such as dark corners can almost be expected with many cameras and can be easily cropped out. But excessive vignetting can be like viewing through a soda straw. Afocal imaging is a compromise, you should expect at least some vignetting. Having said that.. we are after all working with a round image. Fitting it to a rectangular frame forces you to crop off actual imagery. So if you think about it there is always some form of vignetting, it is just either positive or negative. The important thing is to use an eyepiece that can at least fill the rectangular frame with a round image (round image touching top and bottom of frame). That’s the real life view, which has captured all of the information in the telescopes entire field of view. For rectangular format images you can just load it into the pc, zoom in and crop any dead area away, while at the same time centering and framing the subject.
The best eyepieces for this purpose will have ALL of the following characteristics:
-Low Power (The lower the better, the camera zoom will provide plenty of magnification)
-Large Eye Lens (preferably nearly as large as your camera lens)
-Long Eye Relief (short eye relief will result in major vignetting)
-A non-recessed lens (if the eye lens is mounted deep in the barrel it is the same as short eye relief)
-A method of attaching it to the camera (it is compatible with our Digi-Kits, AdaptaView or Universal adapters)
Tips for Afocal Imaging:
-Make sure the camera lens and eyepiece lens are spaced very closely together.
-Use an appropriate eyepiece as outlined above.
-Generally most cameras will need to operate at or near maximum zoom to reduce vignetting to a minimum. On a camera with a large zoom range (such as 10X) this may cause the system to be “overpowered” unless you use a very low power eyepiece.
-Some cameras may work best in Macro mode, experiment with yours to see which mode works best.
-If you’re shooting a large bright object such as the Moon your camera may adjust its exposure and focus correctly so long as the telescope is near focus. But the best results will be achieved by going to full manual mode and adjusting the exposure time yourself. Focus using the telescopes focus knob.
– If you don’t have a remote for your camera use the built in self timer feature so you don’t have to touch the setup (causing it to shake) when taking the photo.
See:
Digi-Kits (afocal kits for hundreds of point & shoot cameras)
AdaptaView Adapter (fits many TeleVue eyepieces)
Attachment Kits (used to connect T-Threaded Eyepieces or our AdaptaView to your camera)
Universal Camera Mount (for point & shoot cameras for which there is no Digi-Kit)