About lenses ?

[Black_Jacobin]

Ok this may sound like a dumb question but what is the difference better all these lens. I understand the difference in zoom so that not what I am asking I mean what else goes into making good lenses.


Also if u have have a canon are the best lenses for the camera a canon. Or can u buy a third party lenses like a sigma and i have also seen one called a tarmor and get the same quality of photo

 

[Jonnyreb]

OK, with lenses there a number of things to consider:

1. Speed - what is the maximum aperture? This is the f/ number (sometimes a range with a zoom. The wider the aperture opens, the lower the f/ number. Currently, Canan make two superfast lenses, the 50mm f/1.2 and the 85mm f/1.2. This means the aperture opens to the focal length of the lens (say 50mm) divided by the f number. With the 50mm example, this means the aperture opens up to 41.7mm - thats a LOAD of light that gets in. More light = faster shutter speed and lower ISO. It also controls the depth of field of focus. Wide open (maximum aperture) , a 50mm f/1.2 will have only about a couple of mm of scene in sharp focus from a distance way of 5 metres. closed down to f/22 hardly any light gets in, so long shutter speed, but you can then measure what is in focus in lots of cm.

2. Construction - the cheaper lenses with have a plastic lens mount. These suffer becuase plastic will wear down over time and foreign bodies get into your camera, messing with the fragile parts. The best will be constructed of metal and have a weather seal.

3. Image Stabiliser - to save too much waffle, suffice to say a gyroscopic motor adjusts a set of internal lenses to counteract camera shake. You can then hand-hold a camera with slower shutter speeds.

4. Price - the cheapest Canon lens is the 50mm f/1.8 (nifty fifty) which is roughly £60 GBP. As you may imagine, its plastic and the f/1.8 is nothing special for a lens of this range. The most expensive is the 600mm F/4 IS L going at £5500 GBP (the 800mm comes out soon, closer to £9000 GBP!!). As with most things, you get what you pay for in terms of build and quality :shrug:

5. Optics - worth a whole chapter to themselves. Ultra low dispersion glass, ground fluorite, etc. All designed to correct the image hitting your camera sensor in terms of light wavelength and to stop the light bouncing from your sensor, the the lens and backagain, which cases lens flare and ghosting with loss of contract.

3rd party lenses - Sigma, Tamron, Tokina, etc will afford almost as good IQ as Canon (in my opinion) but at a lower cost (generally). Remember that 3ed parties are reverse engineered rather than licensed.

I could go on, but you must be bored already by now!!

 

[Chappers]

Can't speak for Nikon, but the quality of canon L glass is better than other manufacturers. Others do get close on occasions but never exceed. Also the speed of auto focus is quicker, sometimes by a fair amount. You can lose the shot if you're trying to focus on a fast moving object and your waiting for the lens to lock focus. Also as already said quality of construction is better.

The difficulty is, does the extra expense warrant the cost? That unfortunately is something you need to answer yourself. You may not see the difference on a small print, but on a larger one you will. But if you never print large, then it could be a wast of money spending the extra.Also you may not need fast focus or tougher construction.

What I need from a lens and your needs may be very different. In many cases the only way to find out is to try the lenses yourself.