[nokiauk]

quite new to this digital SLR lark, but confused as to what range of lenses to carry.

currently have the 18-55 and a 55-200 lens but would like to do some close macro work and also attend air shows and track days etc so need something with a bit of reach also.

also confused with this f value after each lens what does this mean in easy terms as some lenses are the same i.e 70-300 but have different f values?

what are fixed leses good for i.e. 400mm over say a 100-400mm.

[Jazz Monkey Jr]

The f-stop is the maximum amount of light it lets in to the lens, called the aperture. Basically something like f1.2 lets loads of light in but is VERY expensive. Lenses are normally around f4
On a zoom lens you will get different f-stops at different zooms. If it has say f4-f4.5 that means it lets different light in at different zooms, because when you zoom in, the lens usually extends, which means you lose some light.
You only usually need a fast lens if you are doing professional stuff, or have loads of money as it allows you getter a higher shutter speed, for sports and low light.
A fixed lens offers better quality than a zoom lens, but most zoom lenses are pretty good, with the top end, like the canon L series being VERY good and VERY expensive.

I can't recommend any macro lenses, but I am sure someone will.

[h4rri]

Originally Posted by Jazz Monkey Jr

I can't recommend any macro lenses, but I am sure someone will.

Assuming your using a canon .... the 60MM E-FS lense is a superb lense for macro and portrait

[ush flynn]

good explanation for the f-stops there my jazz monkey, i will add that on a longer lens, a large aperture such as f2 or f2.8 your plane of acceptable focus becomes very short. Effectively this means that your subject needs to be pretty much dead on the money focus wise otherwise its not going to look sharp at all. On a shorter lens or an aperture of say F5.6 - F8 then if your panning with a car on a track day like you mentioned you have slightly more flexibility. Not only will more of the car be in sharp focus but, if the car gets slightly closer or further away from you just before you take the shot it will remain inside the plane of acceptable focus (ie... sharp enough to look ok)

confused? let me put it this way
Long lenses with big apertures are great, but your Auto focus system needs to be up to the job. This is why sports photographers use things like canon 1ds II's and Nikon D2x's ... That and they can fire of about 6 shots a second!

[nokiauk]

Originally Posted by h4rri

Assuming your using a canon .... the 60MM E-FS lense is a superb lense for macro and portrait

Thanks was looking at this one or possible the 100mm one for a bit more working distance.


Also zooms, was looking at the 70-300 IS but as I already have the 55-200 despite the price, perhaps the 100-400 L would be better.

[salubrious_k]

If you want a short introduction to aperture and shutter speed, read this: http://www.photosecrets.com/tips.p11.html