24 70mm what does it mean

Flare and ghosting are caused by bright light reflecting off of the surfaces of lens elements, resulting in reduced contrast and sometimes-interesting artifacts. Overall, considering its optical formula, this lens handles flare nicely. There are two lens aberrations that are particularly evident when shooting images of stars, mainly because bright points of light against a dark background make them easier to see. Coma occurs when light rays from a point of light spread out from that point, instead of being refocused as a point on the sensor.

Astigmatism is seen as points of light spreading into a line, either meridional radiating from the center of the image or sagittal perpendicular to meridional. Remember that lateral CA is another aberration apparent in the corners.

While not perfect we're still waiting for a perfect lens , the stars remain relatively round in the corners for good overall performance in this regard. This is a standard zoom lens and the standard zoom lens geometric distortion statement holds true. This lens has barrel distortion at the wide end that transitions into negligible distortion at approximately 28mm and on into pincushion distortion at the long end.

These two lenses are mostly similar in this regard at the longer focal lengths with a modest amount of pincushion distortion at 70mm. The blur and quality of blur seen in the out of focus portions of an image are referred to as bokeh. With an infinite number of test scenarios, evaluating bokeh is challenging. That said, I like what I see. The following are some examples. With the exception of a small number of specialty lenses, the wide aperture bokeh in the corner of the frame does not produce round defocused highlights with these effects taking on a cat's eye shape due to a form of mechanical vignetting.

If you look through a tube at an angle, similar to the light reaching the corner of the frame, the shape is not round and that is the shape seen here. Below, the 24mm image is a top-left quarter of the frame and the other two examples are full images reduced in size.

As the aperture narrows, the entrance pupil size is reduced and the mechanical vignetting absolves with the shapes becoming round. When the aperture is stopped down, point light sources will show a starburst effect of some form.

Each blade is responsible, via diffraction, for creating two points of the star effect. If the blades are arranged opposite of each other an even blade count , the points on the stars will equal the blade count as two blades share in creating a single pair of points.

The blades of an odd blade count aperture are not opposing and the result is that each blade creates its own two points. This lens' nine blade count times two points means point star effects.

Wide aperture lenses usually produce the strongest starburst effects and this lens' 9-blade aperture produces beautiful point stars. This lens has a rather complex design featuring 21 elements in 15 groups and internally looks like this:. This lens has somewhat strong vignetting at 24mm and the CA at 70mm could be lower, but overall, the Canon RF mm F2. This lens produces beautiful, sharp images that are slightly better in quality than even the already-great-performing EF II lens version despite the addition of image stabilization.

The combined performance of a camera and lens' autofocus system is critical to realizing the potential image quality of the combination unless using manual focus. Like the Canon RF mm F2. This lens' AF system repeats the performance of the others and that is a very positive statement.

And, Nano USM lenses focus very smoothly. Canon U. This tiny new Ultrasonic motor achieves the combination of fast, near-instant response during still image shooting, with the smoothness required for good focus during video recording.

The manual focus ring is mid-sized and positioned in front of the zoom ring this is my strongly-preferred position. The manual focus ring electronically controls the focus of the lens. With electronics driving AF, the rate of focus change caused by the focus ring can be electronically controlled and it can be variable, based on the ring's rotation speed. I prefer a linear adjustment speed and have the camera configured for such.

In this mode, the RF F2. The manual focus ring has an ideal resistance and adjustments are smooth and solidly centered with no unusual framing shift happening. An interesting feature mentioned in this lens' press release is "focus breathing suppression". Normal is for the scene to change size sometimes significantly as focus is pulled from one extent to the other, referred to as focus breathing, a change in focal length with focus distance.

This negatively impacts photographers intending to use focus stacking techniques, videographers pulling focus, and anyone very-critically framing while adjusting focus.

The 70mm results look very impressive from this regard while the 24mm results show a bit of magnification change happening. The test lens maintains naturally or perhaps electronically the proper focus distance or very close to it throughout nearly the entire zoom range, being nearly parfocal.

Focus at 70mm and zoom out with the image remaining sharp until near 24mm where a slight defocus appears. The smooth focusing makes focus distance transitions easy on the viewer's eyes and the sound of the lens focusing is not picked up by the camera's mic. Even the lens' aperture changes are quiet and smooth. No focus distance scale is provided on the lens, but a digital scale can be enabled in the electronic viewfinder or on the rear LCD.

The RF mm F2. That short distance results in a very impressive 0. Here is a chart showing the minimum focus distance specs of many similar lenses. At 70mm, a subject measuring approximately 5. At 24mm, with a closer minimum focus distance, a subject measuring approximately 5.

Magnification from standard zoom lenses is generally significantly increased with the use of extension tubes which are, as their name implies, hollow tubes with electronic connections that shift a lens farther from the camera. This allows the lens to focus at closer distances, though long-distance focusing is sacrificed.

The new zoom lock lever secures the zoom position at the extreme wide end, preventing damage during transit. Increased environmental protection Resistant to the harshest conditions, every care has been taken to engineer a solution that prevents dust and moisture from penetrating the body of the lens. Excellent ease of handling The non-rotating front element of this lens means you do not have to readjust the filter after changing focus or zoom when using a polarizing filter or filter holder.

Better bokeh The increase to a 9-blade diaphragm gives a more circular aperture and smoother bokeh. When used with selected lenses, this 12mm extension tube allows much closer focusing. This 25mm extension tube fits between the camera body and the lens, providing closer focusing and macro capabilities to the lens while maintaining electronic contact. A lens hood prevents stray light from entering your lens, keeping unwanted glare from affecting your photos.

Protects the front element of the lens when not in use. Included in the box. This rear cap protects your Canon lens when it's not being used. An 82mm circular polarising filter that makes colours appear more saturated ad reduces reflections from non-metallic materials.

Wide-angle Lenses Achieve a wider field of view and fit more into frame with our range of wide-angle lenses. Find out more. Canon Logo. What is an Aspherical Element? These components are only found in professional quality lenses.

Precision autofocus, with control A ring-type ultrasonic autofocus motor means that you can focus quickly, near-silently and with precision. L-series build quality Only the best technology and production techniques go into the building of each L-series lens. Product Awards. Sample Gallery View Gallery. View full specification. Shop Now. Canon Extension Tube EF 25 II This 25mm extension tube fits between the camera body and the lens, providing closer focusing and macro capabilities to the lens while maintaining electronic contact.

Lens hood EWC A lens hood prevents stray light from entering your lens, keeping unwanted glare from affecting your photos. To add even more praise, I have been easily able to put this lens with a camera body into a regular old purse. The amount of use and adaptability you can accomplish with this lens greatly outweighs any physical burdens of transporting it and many would argue that this lens is the same size as the average, most common lenses.

Now that the mm has hopefully won you over, there comes the burden of choosing which one to get. There are a variety of different mm lenses, ranging not just by brand, but also by aperture and weight. Here are some, just to name a few:. The updated version features improvements to image sharpness, vignetting, and AF speed. That being said, these improvements come at a rather substantial price tag. When pairing with a camera body that features advanced auto-focus systems, the version II is significantly faster than its predecessor.

Like version I, version II features weather sealing with a front filter in place, which separates this lens from its competitors.

Although it does not feature a 2. Another huge benefit is maximum magnification MM. However, both of these lenses are extremely sharp in practical use, a wonderful testament to the models. Unfortunately, there is quite a bit of vignetting at the wider apertures. The ability of this lens to capture sharp images of static subjects in low light is extremely beneficial, given its low light capability.

It took us a few tries, but we finally received a copy of the Tamron VC which produced sharp results throughout the zoom range look for the term "ISO resolution chart" in Bryan's full review for details on our experience with testing this lens.

You can expect anywhere from stops vignetting on a full-frame camera, wide open, depending on the focal length. Flare is decently controlled , but CA wil likely be visible at this lens' shortest and longest focal lengths. Distortion is both typical and average for a lens in this class. This lens' biggest advantage over the rest of the lenses listed here, of course, is its vibration control system which is capable of up to 4-stops of camera shake compensation. The ability of this lens to capture sharp imagery of static subjects in low light is extremely beneficial.

Unfortunately, this lens' biggest crutch is AF consistency. For some lens usage, AF consistency may not need to be consistently spot on. But for a lens that would otherwise be ideal for shooting once in a lifetime moments like weddings , less than ideal AF consistency can be problematic. If interested in acquiring this lens, be sure to purchase from an authorized retailer with a no-hassle exchange policy just in case the lens does not meet your minimum requirements for AF consistency.

Otherwise, utilizing Live View focusing can aid in increasing your hit rate of static subjects. As Bryan mentions in his full review, it's extremely difficult to summarize this lens' performance in a couple of sentences. Unfortunately, it's a bit complicated.