Originally posted by xecutech I am waiting on a k10d camera and I didn't purchase the lens yet. I am new to photography and was wondering which lens to start with? I know this depends on the type of photography I will be doing, but truth is, I don't know. I plan on taking pictures of everything when I get the camera!
This is a tough question, and in the end, you'll have to answer it for yourself - well or badly.
The factors that determine what you should get are these, in no particular order:
1. What you want to photograph
2. How important versatility is to you
3. What you can afford to spend
It might appear that I've omitted something: image quality. But image quality is not a factor - it's what you're trying to purchase. All of us always want the best image quality we can afford, given the lens we select based on its uses and its versatility. Once you know what you're doing, you can buy used and get really good stuff at bargain prices. But for new lenses, quality is generally directly proportional to price.
Versatility = zoom
If you could only buy ONE lens, then you'd really need to ask yourself what you want to photograph, because that would determine how versatile the lens needed to be. If I had to sell all but one of my current lenses, the one I would keep would be the
Tamron AF 18-200mm F3.5-6.3 (IF) XR Di-II. This lens does it all, and does it pretty well - wide angle, mid-range, portrait, telephoto and even macro. If I did not have this lens already and if I could wait another month or two, I'd wait and get the 18-250 cousin of this lens that is supposed to be released in March.
If you can get reasonably close to your subjects most of the time, then you might be happy with a single zoom lens with a range like this
Sigma 18-125 F3.5-5.6 DC lens. There's a favorable review of the lens on the web page I've linked to and I've seen the lens spoken well of elsewhere. I haven't used it myself so I can't say for sure, but I suspect it's not any better in its range than my Tamron 18-200 - but at $279 (Adorama) it's $110 less expensive, and if you don't really need the extra 100mm telephoto capability, then saving that money makes good sense.
The importance of aperture
As much as I like my Tamron 18-200, the fact is that its maximum f/3.5 at 18mm and f/4.5 at 50mm isn't fast enough for shooting indoor sports without a flash, so I have a
Sigma 28-70 F2.8 EX DG. Notice that the Sigma's zoom range is entirely within the range of the Tamron, but the Sigma gives me a fixed maximum f/2.8 at all focal lengths. The Tamron is more versatile, but the Sigma is much faster. When you start staying up late at night reading the listings for Pentax-mount lenses at Adorama, you'll discover that the aperture seems to have more to do with the price of a lens than almost anything else. Big aperture, big price.
Different tools for different jobs
As I mentioned in another thread here recently, I now regard the Sigma as my "indoor" lens, and the Tamron as my "outdoor" lens, although the Tamron is my default, all-purpose lens indoors or out. It does fine indoors if I can use the flash. Before I bought the Tamron, I had a Pentax 50-200mm lens that I should mention here; it's a good lens, well priced and very popular. Anyway, the point I am trying to make is that there does not seem to be a single lens that does absolutely everything. I need different lenses for different jobs. And the jobs are not limited to "indoors" and "outdoors."
I like to shoot birds. You can of course shoot birds with whatever you've got. But to get a usable picture with a 200mm focal length, you have to get really close to the bird and the bird needs to be very cooperative. A 300mm lens is much better - and it's better still if you can go beyond that. Decent 300mm lenses, especially zooms, can be had for under $400 or $500. Superior quality lenses in that range will cost a LOT more than that, so for me they're not an option. I have an smc Pentax-FA J 75-300mm F4.5-5.8 lens that I'm not excited about but which seems to take
decent photos when I use it properly. I will probably sell this lens soon and replace it with something better, but right now it's hard to find something better that I can afford - this
Sigma 300mm F2.8 prime looks pretty sweet, but at $2600, it's out of my league. I also have a Tamron 1.4x converter that helps my 300mm lens behave like a 420mm lens.
I won't mention macro lenses because I don't know much about them myself; many zoom lenses come with some macro (extreme close-up) capability built-in. These are good for taking close-ups of flowers or insects and other disgusting things.
Another subject I have no experience with at all is portraiture, although I think that can serve as a segue to the topic of primes. Once you've got the mid-range, the long range and the close range covered, you may start looking at primes - fixed-focal length lenses that don't really have range at all - in the hope of improving your image quality. Right now I'm lusting after a Pentax 70mm prime that looks like it would be really nice for shooting portraits or people generally, but it's not cheap and I will probably have to resist the temptation. I have a used Pentax 50mm f/1.4 prime that's quite nice, but manual focus. It wasn't expensive. But I'm not sure it's really all THAT much better than the zooms I've got. I've posted some simple comparison shots
here. In the past, it was generally true that zoom lenses were not very good and that for really good photographs you had to use primes. That is no longer the case.
The big three and where to buy
Lenses for Pentax cameras come mainly from three makers: Pentax, Tamron and Sigma. I find Sigma's line to be somewhat bewildering - too many models that are too close to one another in specs for me to feel confident about what I'm getting. Pentax has a reputation for making very good lenses and as you probably know, almost any lens made by Pentax since the mid-1970s can be made to work with the K10D or the K100D/110D digital SLRs. Tamron is also respected. My sense is that they have all made great lenses, and they have all made the occasional stinker. I always look for reviews before buying. I have been inclined to prefer new lenses to old ones, and especially when buying new, it seems pretty clear to me now that, by and large, you get what you pay for.
As for where to buy, the stores I've had good success with include
Adorama,
B&H Photo,
KEH.com (good for used lenses),
Sigma4Less, and Amazon.com. I find Adorama's site the easiest to use. And of course there's also eBay.
Hope this is helpful. Good luck!
Will