[northcoastgreg]

Also, scientifically how does one lens display better colors than another?

It's complicated, but part of it has to do with the coatings used on the lens to improve light transmission. First of all, the coatings are not 100% effective. Some light does not make it all the way through. Moreover, not all the parts of the color spectrum make it through equally. 95% of the yellow and red part might make it through, while only 85% of the blue spectrum does.

In my experience using a variety of lenses, some with outstanding color rendition, some without, the most important part of the equation is the degree of vividness and brilliance of color captured by a specific lens. The reason for this is that brilliance and vividness of color is the most difficult to simulate in post, because you're essentially trying to extrapolate from an inferior color data set. Slight color casts are much easier to fix in post. The color profile of DA 15 sometimes tricks the AWB on the K-5 into rendering dark blue with a slight purple cast. But that's easy to fix with slight alteration of WB in post. While images with dull, pale colors can certainly be improved in post, you'll never quite match what can be attained with a lens with outstanding color rendition, such as a Pentax limited or Zeiss glass.

[Bernie_Rain]

How do people decide on lenses to buy (price/quality, value)?

I have to admit, that I exclusively buy my equipment online.
I decide on which lens to buy based on online reviews, forum discussions and most importantly DXOMark.
I know that DXOMark is not the "holy grail" in benchmarking, but I find it quite helpful often.
I select the mount, different lens manufacturers and then I look at the list (optical score) - my main desire is sharpness - look and feel, weight, vignetting is less important to me.
So I particularly look at the P-Mpix score.

[falconeye]

So I particularly look at the P-Mpix score.

Don't do.
Comparing PMpix makes sense, AND ONLY MAKES SENSE, for a given body and lens max. aperture. All other comparisons are impossible.

It makes so much more sense to dig into details and compare lenses in the detail charts. DxO lens score should be ignored by all but the most experienced readers of DxO lens tests. Really, trust me ...

[Bernie_Rain]

Thanks for your hint.
It is possible to select the body (I have the K-30 so I choose the K-50).

It makes so much more sense to dig into details and compare lenses in the detail charts.

That's correct - in fact I do this, too.

[psychdoc]

This site is way cheaper than some of the others I've seen. Thanks.

However, it would still cost about $90 to try out a lens like the DA* 50-135. That's a lot of scratch for a test run.

If you are fairly sure that you want a certain focal length, many stores will let you return the lens with no questions asked if you are 'not satisfied' with it. I think both amazon and adorama are fairly lenient in their return policy.

P.S: If you are looking for fast zooms that are sharp enough and fairly lightweight, you can't go wrong with this combination-tamron 17-50 f2.8 paired with the pentax 50-135 f2.8. These two zooms are what I use the most. The only caveat to this recommendation is that photography is only a hobby for me. But a hobby I enjoy immensely...

[VisualDarkness]

Thanks for the response, it brings up two new questions that I think I will ask in another thread, but feel free to respond here.

How do people decide on lenses to buy (price/quality, value)? There are only two decent camera stores in Pittsburgh that I know of and neither carries a lot of Pentax stuff. Spending hundreds of dollars on a lens that I've only read reviews on is a big jump.

Also, scientifically how does one lens display better colors than another?

You drool over posts her on the forum with a shop tab open and have a weak moment that you will never regret.

[FrankC]

It started off that the prices on the internet were practically at cost. Why? Because by selling things at such low margins, the seller was getting more visitors which means more $$$ for advertising on their site. This more than made up for the low margins made on the actual sale of the camera - let alone the much higher margins on accessories like lens cleaning kits, straps etc...

MAP has killed the free market and cost consumers billions. The camera manufactures weren't stupid. They figured that they could sell their cameras to the world via the internet, and make even larger profits by eliminating the middle man. However, they couldn't do this if B&H was selling at a lower cost than what they had on their own site. It wouldn't look good, if for example, Nikon was selling the same item at a higher price than anyone else on the internet. Enter MAP. Minimum Advertised Price allows Nikon, and others, to sell their equipment on their website with the security of knowing that no one will have a lower price. No one except for those who walk into a camera shop and make a deal in person with the sales person.
This is obviously price fixing and it's not illegal in the US. MAP has ruined the market place for consumers. Per US FTC guidelines, MAP is not illegal because it doesn't actually prevent a retailer from selling a product lower than MAP, just advertising it. So that's why you'll see "add to cart to see price" buttons. This is a workaround to the MAP restrictions.
When I was selling film cameras, no one sold them for MSRP. If MSRP was $1,500, the camera was selling on the street for around $500.

Just take a look at the 645D. Was at $9,999, then Nikon introduces the D800 and then it immediately drops to $6,999. Someone recently posted that they saw the 645D in a camera window selling for around $5,500. If MAP was banned, this camera wouldn't have ever been at $9,999 in the first place.

We're all getting screwed by this policy, and it's high time that it becomes illegal. In the mean time, I will continue to buy used on eBay or KEH whenever possible.

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Last edited by FrankC; 10-23-2013 at 12:21 PM.