Wide angle lenses - what have I missed?

[blinking81]

Hey,

About to buy either a D40 or D50 and looking at which lenses i'd like to buy with it. I realise the D40 needs AFS lenses to AF, but for this wide angle it wont matter so much to me, as I would rather manually focus anyway.

I'm trying to get my head around all the lenses, and wide angle stuff as stumpted me.

As i had understood it you need a short lens something like this 28mm f/2.8 (http://www.kenrockwell.com/nikon/28f28ais.htm) is a wide angle lens. So then the kit lens on the D40 is a 18-55mm f/3.5 lens. It is shorter, but does this mean it is wider?

There must be something I'm missing. I'm guessing the glass is curved more to make it wide angle, but then how do you know this by just looking at the lens's spec?

Also, if anyone could recommend a nice cheap wide angle prime lens, any advice would be well recieved. Doesn't need AF, just nice and wide.:) Thanks in advance for any advice.

This camera lark is so confusing sometimes.

Eric.

[Nicole]

Here's a quick table from Understanding Camera Lenses (http://www.cambridgeincolour.com/tutorials/camera-lenses.htm) to give you an idea of what focal lengths are considered what:

Less than 21 mm : Extreme Wide Angle (Use for Architecture)
21-35 mm : Wide Angle (Use for Landscape )
35-70 mm : Normal (Use for Street & Documentary)
70-135 mm : Medium (Use for Telephoto Portraiture)
135-300+ mm : Telephoto (Use for Sports, Bird & Wildlife)

Now, the thing that you have to consider is that on a dSLR, there is a crop factor because of the sensor. This is approximately 1.5, so with a 28mm lens, it will be the equivalent of a 42mm lens on a 35mm camera (because a 35mm camera has a full frame sensor).

As you can see from the table above, an 18mm lens is considered a wide angle, but it won't be super wide due to the crop factor. For more info on wide angle lenses, try that first article I linked too, or read the Wikipedia article (http://en.wikipedia.org/wiki/Wide-angle_lens).

Not sure that I can recommend a cheap wide angle prime though, so I'll leave that to someone else ;)

[AZ4Runner]

Its important to note that not all DSLR manufacturers have a 1.5 crop factor. There are a few that do offer full frame sensor models (generally in their more professional level cameras).

[Nicole]

Its important to note that not all DSLR manufacturers have a 1.5 crop factor. There are a few that do offer full frame sensor models (generally in their more professional level cameras).

Very true, however, the D40 and D50 do have the crop factor.

[blinking81]

Again Nicole! Thankyou :)

Thanks for the great links - it finally makes sense to me.

One question though - you not being able to recommend one.. is that due to a cheap wideangle lens being rubbish and not worth the time. Or that you actually dont know one to recommend. Sorry for spoiling the subtly of it, just need to make sure i totally understand what your saying :)

Thanks for all the help :)

Eric

[Nicole]

No worries, I can't recommend one because the only prime that I own is a 50mm (not a wide angle at all) and I haven't used any wide angle primes from any other brands (and looking at prices for wide angle primes is a very scary prospect! ;))

[AZ4Runner]

Thanks for the clarification Nicole. I just wanted to make a point that not all DSLRs have a 1.5 crop factor. I'm not aware of any Nikons that offer a full frame sensor.

[Nicole]

I'm not aware of any Nikons that offer a full frame sensor.

Much to the disappointment of those of us using Nikons ;)

[janesa13]

Check this site for comparison on super wide lenses:
http://www.kenrockwell.com/tech/digital-wide-zooms/comparison.htm

Prices are scary....I want one too!! :(