Teleconverter tamron af28-300mm

The new teleconverters feature a metal lens barrel and share this same design concept. Specifications, appearance, functionality, etc. Catalogs Find a Dealer Photo Gallery. These accessories make it easy to expand the versatility of the attached lens. Increases maximum focal length.

Easy to extend the zoom range. Autofocus and VC Vibration Compensation features are retained with compatible lenses. These optical glasses have a performance equal to fluorite glass. High-refraction low-dispersion elements HLD minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. High Index, High Dispersion elements HID minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture.

Anomalous partial dispersion elements AD minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. Synthetic fluorite elements FL minimize chromatic aberrations and ensure excellent sharpness and contrast even at fully open aperture. Compared with optical glass, fluorite lenses have a considerably lower refraction index, low dispersion and extraordinary partial dispersion, and high transmission of infrared and ultraviolet light.

They are also significantly lighter than optical glass. According to Nikon, fluorite easily cracks and is sensitive to temperature changes that can adversely affect focusing by altering the lens' refractive index.

To avoid this, Canon, as the manufacturer most widely using fluorite in its telephoto lenses, never uses fluorite in the front and rear lens elements, and the white coating is applied to the lens barrels to reflect light and prevent the lens from overheating. High and specialized-dispersion elements SR refract light with wavelengths shorter than that of blue to achieve highly precise chromatic aberration compensation.

This technology also results in smaller and lighter lenses. Organic Blue Spectrum Refractive Optics material BR Optics placed between convex and concave elements made from conventional optical glass provides more efficient correction of longitudinal chromatic aberrations in comparison with conventional technology.

Diffraction elements DO, PF cancel chromatic aberrations at various wavelengths. This technology results in smaller and lighter lenses in comparison with traditional designs with no compromise in image quality.

High refractive index element can substitute one or several regular elements to achieve similar or better optical results, which allows to develop more compact and lightweight lenses. Apodization element APD is in fact a radial gradient filter. It practically does not change the characteristics of light beam passing through its central part but absorbs the light at the periphery.

It sort of softens the edges of the aperture making the transition from foreground to background zone very smooth and results in very attractive, natural looking and silky smooth bokeh. Lens name as indicated on the lens barrel usually on the front ring. With lenses from film era, may vary slightly from batch to batch.

It has an aspect ratio of , and a diagonal measurement of approximately 43mm. The name originates with the total width of the film which was the primary medium of the format prior to the invention of the full frame digital SLR.

Historically the 35mm format was sometimes called small format to distinguish it from the medium and large formats. APS-C is an image sensor format approximately equivalent in size to the film negatives of Medium format is a film format or image sensor format larger than 36x24mm 35mm but smaller than 4x5in large format. Angle of view describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view. As the focal length changes, the angle of view also changes.

The shorter the focal length eg 18mm , the wider the angle of view. Conversely, the longer the focal length eg 55mm , the smaller the angle of view. A camera's angle of view depends not only on the lens, but also on the sensor. Imaging sensors are sometimes smaller than 35mm film frame, and this causes the lens to have a narrower angle of view than with 35mm film, by a certain factor for each sensor called the crop factor. This website does not use the angles of view provided by lens manufacturers, but calculates them automatically by the following formula: A lens mount is an interface — mechanical and often also electrical — between a camera body and a lens.

A lens mount may be a screw-threaded type, a bayonet-type, or a breech-lock type. Modern camera lens mounts are of the bayonet type, because the bayonet mechanism precisely aligns mechanical and electrical features between lens and body, unlike screw-threaded mounts. Lens mounts of competing manufacturers Canon, Nikon, Pentax, Sony etc.

In addition to the mechanical and electrical interface variations, the flange focal distance can also be different. The flange focal distance FFD is the distance from the mechanical rear end surface of the lens mount to the focal plane. Lens construction — a specific arrangement of elements and groups that make up the optical design, including type and size of elements, type of used materials etc.

Element - an individual piece of glass which makes up one component of a photographic lens. Photographic lenses are nearly always built up of multiple such elements. Group — a cemented together pieces of glass which form a single unit or an individual piece of glass.

The advantage is that there is no glass-air surfaces between cemented together pieces of glass, which reduces reflections. The focal length is the factor that determines the size of the image reproduced on the focal plane, picture angle which covers the area of the subject to be photographed, depth of field, etc. The largest opening or stop at which a lens can be used is referred to as the speed of the lens.

The larger the maximum aperture is, the faster the lens is considered to be. Lenses that offer a large maximum aperture are commonly referred to as fast lenses, and lenses with smaller maximum aperture are regarded as slow.

In low-light situations, having a wider maximum aperture means that you can shoot at a faster shutter speed or work at a lower ISO, or both. The minimum distance from the focal plane film or sensor to the subject where the lens is still able to focus. Determines how large the subject will appear in the final image. For example, a magnification ratio of means that the image of the subject formed on the film or sensor will be the same size as the subject in real life.

For this reason, a ratio is often called "life-size". Allows to perform final focusing manually after the camera has locked the focus automatically.

Electronic manual focus override is performed in the following way: half-press the shutter button, wait until the camera has finished the autofocusing and then focus manually without releasing the shutter button using the focusing ring.

Provides highly accurate diaphragm control and stable auto exposure performance during continuous shooting. There is no helicoid in this lens and everything is in focus from the closest focusing distance to infinity.

The entire lens optical system moves straight backward and forward when focusing is carried out. This is the simplest type of focusing used mainly in wide-angle and standard prime lenses. It has the advantage of introducing relatively little change in aberrations with respect to change in focusing distance. With telephoto and super telephoto lenses this method becomes less beneficial in terms of operability because of the increased size and weight of the lens system.

The rear group remains fixed and only the front group moves straight backward and forward during focusing. This method is primarily used in zoom lenses and allows to design comparatively simple lens construction, but also places restrictions on zoom magnification and size reduction. The lens barrel section holding the front lens group rotates to move the front group backward and forward during focusing.

This method of focusing is also used only in zoom lenses. Focusing is performed by moving one or more lens groups positioned between the front lens group and the diaphragm.

As a general rule, the more blades that are used to create the aperture opening in the lens, the rounder the out-of-focus highlights will be. Some lenses are designed with curved diaphragm blades, so the roundness of the aperture comes not from the number of blades, but from their shape.

However, the fewer blades the diaphragm has, the more difficult it is to form a circle, regardless of rounded edges. Excluding case or pouch, caps and other detachable accessories lens hood, close-up adapter, tripod adapter etc. A rubber material which is inserted in between each externally exposed part manual focus and zoom rings, buttons, switch panels etc. Lenses that accept front mounted filters typically do not have gaskets behind the filter mount.

It is recommended to use a filter for complete weather resistance when desired. Helps keep lenses clean by reducing the possibility of dust and dirt adhering to the lens and by facilitating cleaning should the need arise. Lens filters are accessories that can protect lenses from dirt and damage, enhance colors, minimize glare and reflections, and add creative effects to images. A lens hood or lens shade is a device used on the end of a lens to block the sun or other light source in order to prevent glare and lens flare.

Flare occurs when stray light strikes the front element of a lens and then bounces around within the lens. This stray light often comes from very bright light sources, such as the sun, bright studio lights, or a bright white background. The geometry of the lens hood can vary from a plain cylindrical or conical section to a more complex shape, sometimes called a petal, tulip, or flower hood. This allows the lens hood to block stray light with the higher portions of the lens hood, while allowing more light into the corners of the image through the lowered portions of the hood.

Lens hoods are more prominent in long focus lenses because they have a smaller viewing angle than that of wide-angle lenses. For wide angle lenses, the length of the hood cannot be as long as those for telephoto lenses, as a longer hood would enter the wider field of view of the lens. Lens hoods are often designed to fit onto the matching lens facing either forward, for normal use, or backwards, so that the hood may be stored with the lens without occupying much additional space.

If you're looking to speed up your editing workflow, few pieces of hardware can make complex masking, brushing and cloning jobs easier than a digital pen. We look at Xencelabs' latest offering, the Pen Tablet Small. The Great Joy 60mm T2. Apple's flagship M1 Max MacBook Pro offers a combination of performance, efficiency, build quality, and screen quality that you cannot find in any PC on the market, full stop.

What's the best camera for shooting landscapes? High resolution, weather-sealed bodies and wide dynamic range are all important.

In this buying guide we've rounded-up several great cameras for shooting landscapes, and recommended the best. If you're looking for the perfect drone for yourself, or to gift someone special, we've gone through all of the options and selected our favorites. These capable cameras should be solid and well-built, have both speed and focus for capturing fast action and offer professional-level image quality.

Although a lot of people only upload images to Instagram from their smartphones, the app is much more than just a mobile photography platform.

In this guide we've chosen a selection of cameras that make it easy to shoot compelling lifestyle images, ideal for sharing on social media. Submit a News Tip! Reading mode: Light Dark. Login Register. Best cameras and lenses. Started Nov 17, Discussions. Forum Threaded view. Nov 17, Thanks for the help. Bill G Photo Geezer. Photo Geezer's gear list: Photo Geezer's gear list.

Reply to thread Reply with quote Complain. Bill G Photo Geezer It's soft at without a tc and more so with a tc. Reply Reply with quote Reply to thread Complain. It won't work with any official teleconverters.

Thanks Bill G -- hide signature Photo Geezer wrote: Thanks for the great advice. Well, I got the f2. If I had to do it all over again, I would take the and just enjoy.

Affordable quality primes that give you more than mm in reach? Good luck with that Re: Affordable quality primes that give you more than mm in reach? I would have thought the main reason for owning a De is to get top optical quality. Leonard Shepherd's gear list: Leonard Shepherd's gear list.

Leonard Shepherd wrote: I would have thought the main reason for owning a De is to get top optical quality. Bill G -- hide signature F Forum M My threads. You may also like. Nikon D6: initial sample images. Latest sample galleries. Canon EOS R3 sample gallery.