Lens shopping overload... help?

[skilgore]

I am currently researching to purchase a new lens or lenses...

I am currently using the 18-105mm that came with my Nikon D90. Was convinced I wanted to purchase the 18-200mm and possibly add the inexpensive Sigma 70-300mm for fun. But then got distracted looking at the 70-200mm (of course I'd love to have the Nikkor, but would settle for the Sigma) What would be the advantage of the 70-200mm Sigma lens? Would it be better to go that direction and keep my 18-105mm (as I cant afford both the 18-200mm and the 70-200mm right now)? Suggestions?

I am a new member and this is my first post...
looking forward to your feedback.

[zona5101]

Originally Posted by skilgore

I am currently researching to purchase a new lens or lenses...

I am currently using the 18-105mm that came with my Nikon D90. Was convinced I wanted to purchase the 18-200mm and possibly add the inexpensive Sigma 70-300mm for fun. But then got distracted looking at the 70-200mm (of course I'd love to have the Nikkor, but would settle for the Sigma) What would be the advantage of the 70-200mm Sigma lens? Would it be better to go that direction and keep my 18-105mm (as I cant afford both the 18-200mm and the 70-200mm right now)? Suggestions?

I am a new member and this is my first post...
looking forward to your feedback.

Lens shopping is fun! At least I think so. Here is a source that I have been spending time at. There are a lot of reviews on many of the lenses I am interested in. I think both the 18-200 and the sigma have been reviewed. Good luck and have fun.

btw, between the two I'd pick the 70-200f2.8 Sigma...but that's me.

[RichardTaylor]

What will be the main use of your new lens?

[inkista]

Sounds like you haven't yet made up your mind what you want most.

I think you need to do three things to help you decide on a lens.

1) Figure out what your budget is. This is most often the single biggest determining factor on what lenses you're going to be looking at.

2) Read this basic primer on lens features. Particularly the section on maximum aperture. It sounds like you're concentrating on focal lengths, but the max. aperture is as important. Don't be scared off by the f/#s. You gotta learn what they mean sooner or later.

3) Figure out what you want this lens to do that your current lens doesn't. Is it reach? Not wide enough? Is it sharpness? Is it low light capability? Autofocusing speed? Easier to handhold?

[skilgore]

Thank you all for the replies!
Lens shopping for me is like taking a budget and deciding if I go with my HEART or my HEAD? lol...
My HEART says Sigma 70-200mm f/2.8 but, knowing there is a superior lens out there (the nikkor) it makes me hestitate.
My HEAD tells me the 18-200mm is the practical choice. When I ran across the Sigma 70-300mm I thought maybe that combination would give me some practicality but also allow me to do some of what I could accomplish with the 70-200mm also.

So I guess the answer is I am indeed looking at length/reach, though I do realize the importance of aperture.

hmmm...

I am going to read the suggested materials now, any additional advice/feedback or just plain... "this is what I would do" is welcome!!!

[RichardTaylor]

A super zoom (like a 18-200+) isn't really any good at anything although it can be adequate as a travel lens. (I own two of them) that are not used any more mainly because of poor IQ and they are slow to focus as well as poor control of DOF

A 70-300 (smaller aperture lens - ie F4.5-F5.6) makes a good travel telephoto for those occasional long shots but is really too small for a lot of birds and distant wildlife and for a lot of sports.
Couple of examples from last vacation using a 70-300 on a 1.6 crop camera - Canon 40D - both taken around the same time.

(1)

Camera: Canon EOS 40D
Exposure: 0.004 sec (1/250)
Aperture: f/16
Focal Length: 70 mm
ISO Speed: 400

(2) Same spot, almost the same time.

Camera: Canon EOS 40D
Exposure: 0.004 sec (1/250)
Aperture: f/13
Focal Length: 300 mm
ISO Speed: 400

The 70-200 Is a great lens for event photography, like headshots at parades etc but too short for birds etc. I own a Canon 70-200 F4 L

(3) Chinese new year parade.

Camera: Canon EOS 40D
Exposure: 0.002 sec (1/500)
Aperture: f/7.1
Focal Length: 200 mm
ISO Speed: 400

(4) A good long 200mm lens at F2.8 will give you results similar to this, taken with a Canon 135 F2 at F2, with nice soft backgroums

Camera: Canon EOS 40D
Exposure: 0.001 sec (1/2000)
Aperture: f/2.0
Focal Length: 135 mm
ISO Speed: 100

You really do need to think about what you are going to shoot with your new lens - just just mm and aperture are not enough. Go with your head.
I wouldn't buy a super zoom.

[skilgore]

Wow, thanks for the time in your reply Richard!
Those examples really do help.
I am going to focus hard on what my main subject will be, I do tend to shoot a wide range of subjects, probably part of my trouble in making a decision
Thanks again!

[inkista]

Originally Posted by skilgore

Thank you all for the replies!
Lens shopping for me is like taking a budget and deciding if I go with my HEART or my HEAD? lol...

Pretty much like that for all of us, I think. My last lens purchase was completely with my heart and not my head. I didn't need the lens. But I wanted it so very badly.

My HEART says Sigma 70-200mm f/2.8 but, knowing there is a superior lens out there (the nikkor) it makes me hestitate.
My HEAD tells me the 18-200mm is the practical choice. When I ran across the Sigma 70-300mm I thought maybe that combination would give me some practicality but also allow me to do some of what I could accomplish with the 70-200mm also.

The one thing the Sigma 70-200 f/2.8 will let you do neither of the other lenses can is shoot at f/2.8. It's more flexible in terms of lighting conditions and the shutter speeds you can reach with it (which is non-trivial when you're talking about telephotos), but it's $800 or thereabouts, iirc. and that pricepoint it's a leeetle harder to compromise on image quality and the lack of stabilization. OTOH, the Nikon 70-200 f/2.8 VR costs more than twice as much.

The Sigma 70-300 has more reach and a much lower price tag ($200-$400, depending on which version you go for), but it does now come in an HSM OS (Sigma-speak for AF-S VR) version. An 18-200 is great as a travel lens, but has image quality compromises to cover that large of a zoom range. And both of these guys are slow.

One thing to keep in mind if you've never shot with a telephoto lens before is that you need faster shutter speeds for the longer focal lengths. This is why stabilization becomes more of an issue. The rule of thumb for eliminating camera shake blur from a handheld shot is to shoot with a shutter speed of 1/focal_length or faster. That means, if you're at 200mm, you want to be at 1/200s or faster. And at 300mm, 1/300s or faster.

Stabilization can help lower this restriction. If you have two-stop VR in a 200mm lens, then you only need to be at 1/50s or faster. Without stabilization, with a telephoto or supertelephoto, you're almost always at iso 400 or above, even in bright sunshine to get the higher shutter speeds you need.

But, on the third hand, a monopod works as well or better than VR, cost <$100, and works with every lens you own.

[skilgore]

Lots of very informative things here to consider, thanks so much for your time, I should be making a decision soon, your input has definitely been of great help!