Looking into a wide angle lens. I already have a 18-70mm and a 70-300mm nikon lens. Want to get a decent one. Also a Nd filter, which one would work best and what does the numbering means?

Also is a macro lens worth it?

 

Your 18-70mm is already a wide lens up to roughly 45mm.
Anything wider and you start to introduce a fish eye, bubble effect.
As for ND filter the number represent the number of stops, or how much light it reduces. Which is best depends on the situation and the f values or the lens in use.

Macro is for extreme close ups, there is a thread here with pic as examples.

Heres something I made about focal lengths, as you can see the mm distance on a long lenses changes little, say 150mm vs. 200mm. However on a wide lens, a 20mm is much different then a just a 30mm. Maybe this will get use some prospectives on what you may need.
Do keep in mind your camera is not a 35mm, so the effective focal range is different depending on camera.

 

I am thinking in 35mm term, you could stand to go wider if you really need it, since I think your 70mm is really 50mm or what is consider to be 1:1.

There some smart guys on here, that could properly fill the gaps for your case, and ofter some lenses advice

 

yeah the fish eye effect is what I'm looking for.

 

There's wide angle, which the 18-70 provides, then there's ULTRA WIDE ANGLE which a 10/12-20/22mm will provide. I've already posted my samples of the Sigma 10-20... To put it mildly I regret not getting a UWA lens earlier. Everyone should have one in their bag.

MagicPie is referring to 18mm in full frame sensor terms, which would be UWA with a full frame body. You'd have a whole bunch of options with zoom lenses with a full frame body to go into UWA territory.

You can view Flickr's pool and opinion of users here:
http://www.flickr.com/groups/sigma10-20/

If you want fisheye... the Tokina 10-17mm UWA, which is the same as the Pentax 10-17 fisheye, though of course, the Tokina is available in Nikon and Canon mounts...

Here's someone who tested out both... the fisheye is 180deg field of view... so you get more view at the same focal length.
http://www.pbase.com/alinla/1017_vs_1020

You can get some pretty interesting shots with a fisheye... remember, B&H has discounts available for both these lenses, look on the 4th page of my Sigma 10-20mm test thread for the codes to B&H.

Of course, Nikon offers a UWA also, but much more expensive than the Sigma. Tokina has a 12-24 regular also, but the difference between 10mm and 12mm on cropped sensors is A LOT. Tamron has one too which starts at 11mm. Lastly, Sigma has another one, a 12-24, which also can go on full frame bodies. The Sigma 10-20 is only for cropped sensor bodies.

Macro? I'll have my Canon 60mm Macro review up shortly.

 

Thanks.

 

I knew ctwentytwo would come through