Lens For Canon

Canon lenses have two types of mounting (lens holder), the EF and EF-S EF lenses while divided on the L series and Non-L series. EF-S lenses can be used on cameras with crop factor, but can not be used on a full frame camera (like the 5D or 1Ds), however there are adapters to use it on a full frame camera is pretty severe impact on Vignette. Readings on the lens, like the EF 24-85mm f/3.5-4.5 USM has a description as follows:

EF = type lens mounting
24-85mm lens focal length = distance, means that this lens has the ability to zoom 24mm (wide) to 85mm (normal / semi-tele).
= f/3.5-4.5 lens has a maximum aperture 5.3 aperture on the focal distance of 24mm and maximum aperture 5.4 aperture at 85mm distance.
USM = Ultra Sonic Motor drive (naming types of auto focus motor in the lens of canon)

for lens EF 24-70mm f/2.8L USM, the letter L on the back indicates the L-series lens, which lens is the best series Canon lens with excellent optical quality, and better endurance (dust proof & splash proof, CMIIW). f/2.8 shows that this lens has a maximum aperture opening a good fix on the focal distance of 24mm and 70mm. Long lenses are different physically, is very relative, depending on the number of optical elements used. Length lens that does not necessarily indicate a lens with focal distance away.

Figures indicated on the lens aperture does not mean the lens is only capable of having aperture openings according writings, eg, EF 24-85mm f/3.5-4.5 USM, does not mean the lens is only capable of having the aperture from 3.5 up to 4.5 only, it is tatapi maximum aperture. In addition to the maximum aperture, the lens is still able to achieve the minimum aperture (rata2 until 29). So aperture 5.6, 7.1, 8, 11, etc ... can still be done by the lens.

Basically, the longer focal length lens, vibration occurs even more vulnerable and therefore may result when the lowlight bigger blur. To cope, can Rev the ISO and / or reposition the camera as steady as possible (could be assisted monopod). Actually there are theories that do not know how to explain it, to shutter speed and not so good results blur caused by vibration, attach the shutter speed using the formula 1 / focal length lens, eg 75mm lens focal length, so a good shutter speed 1 / 75 (the minimum, if can the sooner the better).

For panning, in fact the longer the lens focal length gets easier, shutter speed and aperture is very relative to the light conditions. In general shutter speed that can be used between the fifth until 1 / 25, it also depends on the speed of moving objects. What is certain is the smaller the aperture the better the results of blur, or a noisy background will also produce a better blur. I hope to explain ...


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