[Saaby]

The kit lens also has the non-rotating focus ring, generally found on more expensive lenses, that makes polarizers easier to use. The hood has that little polarizer-door in it too.

Moved to lens forum

[Marc Sabatella]

Blur-free yes, but by necessity a larger portion of the image will get "out of focus" the larger the aperture becomes. Fast glass buys you speed but at the expense of usable sharpness. At f/1.4 the smallest camera movement can place the subject out of focus and there isn't a lot of the subject that can be placed in focus.

Good point. This is why in practice, if I'm not specifically looking for shallow DOF effects, f/2.8 is really about as large an aperture as I would normally want.

Faster shutter speeds can also be obtained by cranking up the ISO. This has the advantage of leaving the DOF still usable but the disadvantage of introducing noise if exaggerated.

Right, but of course, even at ISO 1600 (as high as some cameras go), you'll need f/2.8 in many tyo get handholdable shutter speeds in many situations. Some situations will reqire f/2.8 even at ISO 3200 or 6400. So even if you raise the ISO as high as it goes, there will be situations where the kit lens just isn't "fast" enough.

[Marc Sabatella]

At most focal lengths, the kit lens will only give you an aperture of f/4.5 at best. If you're shooting in low light - indoors with no flash, for example - that might translate into a shutter speed of 1/10" or slower at ISO 1600. A lens with a maximum aperture of f/2.8 would let you shoot at 1/30".

1/40th not 1/30th yes?

By my count, f/2.8 to f/4 is one stop, f/4 to f/4.5 a half a stop more. 1/10" to 1/20" is one stop, 1/20" to 1/30" half a stop more.

A lens with f/1.2 would let you shoot at 1/60", and one with f/1.4 would let you shoot at 1/120".

Is this a typo or am I missing something?

[Just1MoreDave]

I think the real difficulty is answering the question "how good do I need my glass to be?" It usually comes up when budget, size or weight is a consideration. The DA*50-135 f2.8 is the perfect lens for a lot of situations, until it comes to those three factors.

[Marc Sabatella]

A lens with f/1.2 would let you shoot at 1/60", and one with f/1.4 would let you shoot at 1/120".

Is this a typo or am I missing something?

Typo. I meant f/2, not f/1.2. f/1.2 would give you 1/180".

[brucestrange]

My da 35mm f/2.8 macro is so much sharper than my da 16-45mm f/4 ever was.

That's interesting in light of what photozone.de has to say. According to them, the DA16-45 beats down the DA35 in the sharpness category. That's not to say it's a better lens. They're both considered sharp, but there's also contrast, color rendering, and bokeh to take into account.

I'm thinking there must be more to 'good' glass than just image quality? do they focus faster? I know some of them have a wider apeture range, but what does that really mean for me?

If you're not looking for an improvement over image quality or a faster aperture, there's not really a reason for you to replace your kit lens. I don't think you'll find a lens that focuses appreciably faster. Some people place a lot of stock in image quality and faster aperture settings, though, and those people end up buying "good" glass. I will say this, though, there is a lot of "good" glass to be had for well under $500.

[Presto]

I think that the main reason to buy "better" glass is if you are hitting the limits of the lenses you have for some reason, or you shoot in a lot of similar situations that a particular lens will get the results you desire. For instance; if you shoot in low light situations (night clubs, wedding chapels, reception halls, etc.) you need faster glass. There is no doubt that you should seriously consider the F/2.8 zooms, or fast primes. If you take a lot of portraits, you probably need a fast telephoto prime to blur the background and have the subject razor sharp. (or at least part of the subject razor sharp) There are tons of situations that call for a "better" lens of one kind or another, but if you don't find your lens lacking for what you are doing, you have "good" glass already. In that regard; Pentax does not make any "bad" glass. I haven't seen any that disappoints. I just see some lenses that make more sense for certain situations. A good lens/camera simply get out of the way of the photographer, and allow him/her to capture what they see, or want to see.

By the way, you are not allowed to look at my signature! I am a wierd situation. I don't have a camera store within well over an hour's drive at which I can look at Pentax equipment. I have to order everything that I get. Because of this problem, I buy what I am fairly certain will fulfill my needs and then some. That being said, I have not been disappointed in any of my purchases.

[farfisa]

If you are happy with the kit lens, continue to be happy with it and don't let your fun be spoiled. It is generally regarded as a very good lens and there is no reason to become unhappy with it just because others are enjoying different lenses more.

Excellent advice!

You'd be saving yourself a lot of money (/pain/ecstasy/anguish/...) by walking away right now happy

[er1kksen]

All of these technical factors like sharpness, contrast, color, bokeh, etc. different lenses have different "looks." This is a lot harder to define and much more subjective, but it's still important. In my olympus setup I started out with the old kit lens (not known for being great) and later bought a 70-300, which gave a similar overall "look" despite being sharper and having more subject isolation and stronger color etc. Then I bought a sigma 30mm f1.4, which apart from its technical differences (much sharper, faster aperture, warmer colors) gave a completely different "look" which i really preferred. That said, now that I've sold all the Oly stuff that's worth anything (the camera and kit lens are too beaten up to sell) I'm back to just the kit lens until my K20D arrives, and it does surprisingly well when stopped down to about f7, given its mediocre performance in general. Interestingly, their newer kit lens (much better in all technical aspects and one of the sharpest kits out there) gives a different "look" as well.

In the pentax world, that's one reason why some buy the 77 limited over the 70 limited; even though the 70 has its CA and PF under better control, is just as sharp and well-constructed, is cheaper, barely slower, faster focussing, smaller, and lighter, the 77 just has this special "look" that some feel is completely worth it.

[Ron Boggs]

No mention yet of competitiveness vs other photographers or other lenses...

First, I agree that if you are getting the images you want and enjoy with the lens or lenses you have, then "don't worry be happy." There is nothing "wrong" with your kit lens, nor with any lower priced or used lenses. I was quite happy with the kit lenses that came with my SF10 back in the late '80's. Then I started selling magazine articles with photos.

Here's where I had to "suck it up" and face the music. Sometimes the editors bought my photos to accompany the articles. Sometimes they bought somebody else's photos to accompany my articles--ouch! Part of the problem was lack of good photography and compositional skills on my part. And part of the problem was that other photographers were submitting images that were more sharp and contrasty than mine...and with better out of focus areas and better color pop and etc. etc. etc.

Now having sold a couple hundred articles and nearly 1000 photos to the magazine market, I must say that upgrading to the best glass available helped control one of the variables that was within my control. I'll take a bit of credit for "forcing" myself to become a better photographer, but I won't discount the effect that better image quality played.

If you want to compete in the freelance photo world, you have to shoot competitive images. An extra 10% gain in lens quality may cost an extra 200% in lens price. But if it helps sell more images, then the cost is obviously worth it. If you aren't selling images and seldom print bigger than 5x7, primarily view your stuff on a computer screen...the only reason for "better glass" is personal pleasure. Only you can place a value on the personal pleasure you obtain from higher quality images. And don't let anybody "force" you to define your personal pleasure by the criteria they use to define their personal pleasure.

[reeftool]

I think the term "good glass" would speak for itself and the importance of having "good glass" on your camera shouldn't need to be questioned.

Expensive glass and good glass aren't always the same thing. While the 18-55 kit lens gets bashed a lot, I consider it "good glass". It isn't too fast but I have been very happpy with the results and if I need a fast lens, I will use my 55 Takumar. I have no plans to replace it with another zoom in that range.

[EricT]

That's interesting in light of what photozone.de has to say. According to them, the DA16-45 beats down the DA35 in the sharpness category. That's not to say it's a better lens. They're both considered sharp, but there's also contrast, color rendering, and bokeh to take into account.

I was also puzzled by this fact. The photozone review also characterizes the bokeh of the 35mm as "nervous" and "slightly disappointing". The 16-45 is also often hailed as having great contrast and color rendition.
Anyone who have tried both lenses care to comment? Obviously the 35mm gives you 1:1 macro and f/2.8, but being a Ltd lens I would expect IQ to be better as well.

[Nesster]

I'm baffled by photozone as well - I wouldn't say the 16-45 beats down the 35, but the two seem to be in a similar performance category. Which is surprising - when comparing to the 43 for example, I find the photozone result reasonable, and visible. Perhaps their sample 35 wasn't a good one.

The 16-45 does have good contrast and color - but this is to some extent an optical trick, one that becomes visible when comparing directly to the 43, for instance. I don't think the 'trick' matters much, as the end result is what matters, and the 16-45 makes excellent photos. So does the 43, but with a slightly different flavor.