Superior, reliable image quality with a universal lens
The lens construction features 16 elements in 12 groups. This includes three Molded-Glass Aspherical elements, one Hybrid Aspherical element, two LD (Low Dispersion) elements, one XR (Extra Refractive index) glass element, and one element of UXR (Ultra-Extra Refractive Index) glass, which has greater refractive index than XR. The full use of specialized glass elements in the design contributes to thorough compensation of optical aberrations. In addition, the use of the latest coating technology for suppressing reflections on lens element surfaces minimizes unwanted flare and ghosting and assures sharp, crisp, high-contrast images.

A further expansion of the imaging range
With a minimum focal length of 16mm (35mm film equivalent: 24.8mm) at the wide-angle end of the zoom range, and a maximum focal length of 300mm (35mm film equivalent: 465mm), this remarkable new lens provides a zoom ratio of approximately 18.8X.

Responding to requests from consumers who wanted to be able to photograph subjects with a wider viewing angle than is possible with conventional high-power zoom lenses, Tamron has begun developing a unique lens with a minimum focal length of 16mm. At the telephoto end, the maximum focal length has been increased to an impressive 300mm. Users of this new lens can enjoy unprecedented framing flexibility by easily adjusting the angle of view using the convenient zoom ring.

Using a new design approach to create an ultra-compact lens

The latest optical technology has been used to provide an expanded zoom range (compared to the B008) at both the wide-angle and telephoto ends, without necessitating the use of an oversized lens body. By employing UXR glass (which helps to reduce the size of the front lens diameter), an optimized layout of the Molded-Glass Aspherical elements, and adopting a 5-lens-group zoom system approach to provide enhanced design flexibility, the new lens embodies the fusion of state-of-the-art optical design, sophisticated mechanical design, and high-precision lens manufacturing technology, thereby attaining a compact size, an unprecedented zoom range, and superior image quality.

A minimum focusing distance of just 0.39 meters supports an extensive range of macro photography capabilities
The new lens provides a minimum focus distance of 0.39 m over the entire zoom range, with a maximum magnification ratio of 1:2.9. This makes it possible to get right up close to the subject of the photo to enjoy easy, stress-free macro photography.

PZD (Piezo Drive) delivers faster, quieter autofocus action
The PZD (Piezo Drive), an advanced standing-wave ultrasonic motor system, delivers faster, quieter, more precise AF action when the autofocus is engaged. There is enhanced support for contrast-detection AF capabilities, and focusing when in live-view mode has been made smoother. The new lens also features full-time manual focus, a function that was not provided by B008, making manual focusing more convenient.

Sharper images with VC (Vibration Compensation)
Tamron’s acclaimed VC (Vibration Compensation) mechanism is incorporated into the new lens. VC reduces image blur caused by camera shake to deliver significantly sharper images even when shooting handheld at long telephoto settings.

Moisture-resistant construction for worry-free outdoor shooting

CES 2016 announcement.

Specs

• 17 lenses in 10 groups
• 6-steps of compensation synchronized in-lens and in-body Image Stabilization
• 140 cm minimum focusing distance
• 77mm filter thread
• 93x227mm
• 1475g
• OIS stabilization
• Weather sealed
• $2499 / 2600 Euro at
• US - http://www.amazon.com/Olympus-M-Zuiko-Digital-300mm-Black/dp/B01950SVHY/
• DE - http://www.amazon.de/gp/product/B019MYY38O/
• UK - http://www.wexphotographic.com/buy-olympus-m-zuiko-digital-ed-300mm-f4-is-pro-lens/p1588759

More info - http://www.getolympus.com/us/en/lenses/pen-omd/m-zuiko-ed-300mm-f4-0-is-pro.html?ref=CJ

Super Telephoto Power in a Rugged, Compact, Lightweight Package

Super telephoto lenses are right at home in harsh environments. The M.Zuiko 300mm f4.0 IS PRO lens keeps dust and moisture at bay with an astonishing 11 separate hermetic seals so you don't have to worry about the weather when you're tracking an elusive osprey or photographing a rainy soccer match. It's nimble, maneuverable and easy to carry.

The Highest Resolution in Olympus History

The M.Zuiko 300mm f4.0 IS PRO's cutting edge internal lens architecture virtually eliminates peripheral chromatic abberation and color bleed while ghosts and flares are minimized by nano-technology lens coating, delivering the highest resolution in Olympus' storied history of innovation in optical glass.

Sync IS

The in-lens stabilization works in perfect harmony with the 5-Axis Image stabilization of OM-D cameras to deliver 6 shutter steps of performance, ensuring crisp, clear telephoto images, even off tripod. Explore unique angles like low to the ground macros and overhead nature shots

Fast, High-Precision Autofocus

Smooth coordination between a camera's autofocus and image stabilization is especially important when shooting with long focal lengths. The powerful 5-Axis Sync IS ensures harmonious operation between the in-body and in-lens stabilization units for focusing times of under 400 milliseconds.

Impressive Construction

Three difficult-to-fabricate Super ED lenses, 1 Extra-High Refractive Index lens and 3 High Refractive Index lenses are lavishly combined to produce excellent resolution and a compact size. Advanced design techniques and manufacturing technologies result in these high-precision, large diameter fine-polished lens elements that offer excellent image quality.

Close Up Performance

With a minimum focusing distance of 1.4m (4.5ft) and a maximum magnification of 0.48x (35mm equivalent), this super telephoto lens is equally adept in close quarters, delivering stunning, high magnification macros.

Focus Limiter

A focus limiter button is adorned on the side of the lens allowing you to chose from three preset focus positions: 1.4-4m, 4m - infinity, or the total range of 1.4m - infinity.

Lens Coating

Bright light sources like the sun can reflect and bounce off the many lens elements found in a complex lens. Olympus developed ZERO coating and Z coating Nano to suppress the ghosts and flares caused by reflected light, ensuring bright, artifact-free images withs superb color contrast.

Extreme Portability

Weighing in at a mere 27lbs (1,270g), the M.Zuiko 300mm f4.0 IS PRO is a fraction of the size of comparable 600mm DSLR lenses. It's so small and light that it can easily fit in your carry on luggage or hiking backpack.

Lens Function Button

A dedicated Lens Function button on the lens barrel can be programmed to any of 27 different functions such as Focus Lock, Test Picture and Preview, allowing for quick changes on the fly without diving into the camera menus.

Silent Telephoto Shooting

In combination with the completely silent OM-D electronic shutter, super telephoto images can be taken in areas that can not tolerate camera noises like a concert performance.

1.4x Teleconverter MC-14

Enhance the versatility of the M.Zuiko 300mm f4.0 IS PRO lens with the addition of the 1.4x teleconverter for an impressive maximum focal length of 840mm (35mm equivalent). Weather sealing is maintained with the teleconverter.

Key specs:

• Nano Crystal Coat
• Phase Fresnel element
• 755g
• VR
• $2000 price

PR

Nikon has also introduced the AF-S NIKKOR 300mm f/4E PF ED VR, the world’s lightest 300mm full-frame fixed focal length AF lens, which is nearly 30% shorter and 1.5 lbs. lighter than its predecessor. Extremely easy to handle and built to suit the needs of serious photographers in the field, the new 300mm f/4 lens utilizes Phase Fresnel optical technology to help correct chromatic aberration and reduce the overall size and weight of the lens, making it easy to pack for any assignment. Capable of producing tack-sharp images and beautiful background blur at a distance, Nikon’s newest FX-format lens also features four and a half stops of VR image stabilization, a VR Sport mode, VR tripod detection as well as several of the latest NIKKOR optical technologies including electromagnetic aperture control, a Silent Wave Motor for quiet AF operation, ED glass for further controlling chromatic aberrations and Nano Crystal Coat for superior image quality.

Available at:

• http://www.amazon.com/Panasonic-100-300mm-4-0-5-6-Aspherical-Interchangeable/dp/B0043VE28S/
• http://www.bhphotovideo.com/c/product/736369-REG/Panasonic_H_FS100300_Lumix_G_Vario_100_300mm.html

Not produced yet

** Specs**:

• Advanced Optical Image Stabilization
• Magnesium alloy body
• Weather sealed
• Filter slot
• 2 meters minimum focus distance
• Custom focus range can be set
• iFunction button
• Super Sonic Focus Motor

State-of-the-art optical design technology delivers superior image quality
The advanced optical construction of this lens includes four elements of LD (Low Dispersion) glass, three Molded-Glass Aspherical elements, one Hybrid Aspherical element, one XR (Extra Refractive Index) glass element, and one element of UXR (Ultra-Extra Refractive Index) glass, which has greater refractive index than XR. The full use of specialized glass elements in its design contributes to making this outstanding lens as compact and lightweight as possible, while minimizing aberrations, resulting in superior image quality. Particularly impressive is the thorough compensation of chromatic aberrations at the telephoto end, yielding images of enhanced clarity and crispness.

Focus on portability - The lens is now even smaller and lighter
In addition to state-of-the-art optical design that facilitates downsizing of the lens body, the mechanical design, which incorporates a highly sophisticated multi-stack-cam layout that takes up far less space, and PZD (Piezo Drive), an autofocus drive system with a simpler, more compact structure, has made it possible to reduce the overall dimensions of this lens compared to the existing Tamron 28-300mm (Model A20). These technologies are the fruit of Tamron’s more than 20 years of research and development in the high-power zoom lens field.

Advanced anti-reflection coating
The application of BBAR (Broad-Band Anti-Reflection) coatings for suppressing reflections on lens element surfaces minimizes unwanted flare and ghosting to deliver sharp, crisp, high-contrast images.

PZD (Piezo Drive) delivers faster, quieter autofocus action
The PZD (Piezo Drive), a standing-wave ultrasonic motor system, delivers faster, quieter, more precise action when the autofocus is engaged. The full-time manual focus system is easy and intuitive, enabling quick and convenient manual focus at any time.

VC (Vibration Compensation) Tamron’s acclaimed VC (Vibration Compensation) mechanism reduces image blur caused by camera shake to deliver significantly sharper images even when shooting handheld.

Circular diaphragm facilitates achieving spectacular blur effects Using a circular diaphragm, this lens achieves spectacular background blur effects that enable creative use of depth of field.

Moisture-resistant construction for outdoor shooting
Moisture-resistant construction helps prevent moisture from penetrating the lens.

Will be available on m43 and E mounts.

Price - about $299

Specifications:

• 300mm focal length
• 9 elements in 9 groups, 1 ED element
• F6.3 fixed aperture
• Mounts - Canon EF-M, Fujifilm X, m43, Sony E mount
• Weight - 318g
• Diameter - 65mm
• Length - 74mm
• Price - from $279

Available at:

• http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_nkw=300mm+rokinon&_rokwmt=1

Specifications:

• Focal length - 300mm
• Maximum aperture - f4
• Lens construction - 15 elements in 11 groups
• Angle of view - 8 degrees @ 15 feet
• Closest focusing distance - 4.9 feet
• Filter size - 77mm
• Dimensions - 3.7 inches in diameter and 8.7 inches long
• Weight: 2.6 pounds

Available

• http://www.amazon.com/Canon-300mm-Telephoto-Lens-Cameras/dp/B00009R6WW/

Reviews

• http://photo.net/equipment/canon/300-4

Won't be cheap, but hope that it'll be quite compact.