more info: www.swarovskioptik.com To set up the Swarovski UCA for a DSLR camera: – align the supporting platform so that you have a large area, big enough to support your DSLR, as opposed to rotated and made more compact for a point and shoot camera (see video) – attach the camera on to the removable base plate, making sure that the screw is in the centre position on the base plate (as opposed to the off-set position for many compact cameras) – the type of camera objective lens you use is important for mounting and using your DSLR for digiscoping. Normally, your best bet would be to use something like a fixed 50mm f1.8 lens (aperture wide open). Pancake lenses are great as they keep the camera’s weight as close to the telescope’s eyepiece as possible. It is possible to use a small kit zoom with some small DSLRs. eg with a Canon 1000D setting the 18-55mm zoom to 37-55mm should give you a vignetting free image. The problem with zoom lenses are twofold: they generally do not have the quality of the fixed lenses, and they are longer so there is greater leverage holding the weight of the (comparatively) heavy DSLR far away from the attachment point and the scope’s eyepiece. – slowly slide the camera on to the mounted UCA making sure the camera lens does not bash up against the telescope’s ocular lens – adjust the height by loosening the screw on the right – now loosen the large black screw underneath the platform to adjust the horizontal and distance alignment. Slowly move the …

Check us out at www.tutorvista.com get a free tutoring demo A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element. A compound lens is an array of simple lenses (elements) with a common axis; the use of multiple elements allows more optical aberrations to be corrected than is possible with a single element. Lenses are typically made of glass or transparent plastic. Elements which refract electromagnetic radiation outside the visual spectrum are also called lenses for instance, a microwave lens can be made from paraffin wax. A photographic lens may be made from a number of elements: from one, as in the Box Brownie’s meniscus lens, to over 20 in the more complex zooms. These elements may themselves comprise a group of lenses cemented together. The front element is critical to the performance of the whole assembly. In all modern lenses the surface is coated to reduce abrasion, flare, and surface reflectance, and to adjust color balance. To minimize aberration, the curvature is usually set so that the angle of incidence and the angle of refraction are equal. In a prime lens this is easy, but in a zoom there is always a compromise. The lens usually is focused by adjusting the distance from the lens assembly to the image plane, or by moving elements of the lens assembly. To improve performance, some lenses have a cam system that adjusts the …

This video features three of the Sony G Series Telephoto zoom lenses.

testing old lenses – nice diffusion effects with an old tamron zoom lens low light problems with an old wide angle lens Canon 50mm EF 1.8 ii Canon 28-70mm EF 4-5.6 ii (with macro, and fish eye) Tamron 70-300 EF 4-5.6 127DE still getting the chopping effect when the camera moves suddenly

I’m going to a concert in July and I’d like to have a good zoom lens so I can get good pictures.
I really don’t want to spend more than 0 max.

New lens. I noticed some free play in the Zoom ring, particularly when set at 85mm. Held gently between finger & thumb tips, I ‘rotate’ the zoom ring without actually trying to rotate the lens. This results in what I feel is unacceptable looseness in the zoom ring. I have compared this lens to two others. One on a store shelf and the other owned by a camera store proprietor that has been used for around 8000 shots. Both those lenses do not display any free play like mine does. Could owners of the same lens experiment with their own and let me know if you experience the same free play please. Thanks