What kind of priority do you give to lab tests, numbers, etc, when buying glass?

[splproductions]

Whether this is a good thing or not, I tend to do all of my research online, and then do all my purchasing online (this goes for everything, not just photography equipment). I don't have any friends into photography, so pretty much 100% of my knowledge and experience with a certain lens comes completely from the hours and hours of reviews and lab tests I read.

When considering a lens purchase, how much credence or priority do you give to lab tests (i.e., quantitative numbers)? For example, I seem to obsess over the MTF50 charts or other specific measurements of different lenses.

I know a lens has other characteristics that are qualitative and can't be charted and graphed. So how much importance do you all place on those MTF50 numbers for example? Are these lab tests not really that important when it comes to the "real life" performance and usage of your lens?

 

[orb9220]

Not my cup of tea tho will read their conclusions pointing the Pro's & Cons of any lens.

Best reviews I get are from other users in flickr. As there are dedicated groups to specific lenses. With browsing the Pics & and reading the threads. Or asking a specific question to be answered hopefully by others in the know from using.

Charts are great for guidelines but wanting human experience in real world situations to chime in.
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[Derrel]

I do not shoot many pictures of test charts or resolution targets, but if I DID, I KNOW which lenses would do the best!!! (get my meaning here?)

MTF charts are only ONE of the factors I take into consideration. As you gain more experience with lenses, you can start to literally "see" different imaging characteristics that various lenses demonstrate. How a lens performs in real-world picture taking situations that are LIKE MY INTENDED situations, is a HUGE factor for me. SOme lenses are simply terrible when shot directly toward bright light sources, like evening sun. A good lens in point: the original 70-200 VR-Nikkor. It has good MTF stats, and good performance, and very lovely bokeh, fast focusing, WONDERFUL ergonomics, with four, individual, end-of-barrel AF LOCK buttons that are PERFECTLY positioned for shooting portraits and events, two for wides, two for talls...adding yet another Nikon advantage to the "focusing, then locking focus" with LENS-mounted focusing. The lens is very slender, and has superb controls...MUCH sleeker and sexier than my Canon 70-200/2.8-L IS USM...the Nikkor is BETTER on crop-sensor than the Canon is...the Canon is better as a FF lens...anyway...the "stats" show the 70-200 VR Nikkor, Mark I, to be an excellent lens in almost all respects. its balance, fit,m finish, controls, and handling, plus its bokeh AND its lack of focal length LOSS when set to the longer zoom range at closer distances makes it a fantastic lens on paper. And it is fantastic in actual use. EXCEPT when shooting toward the sun....when it ghosts and flares like a bastid.

MTF charts don't tell us how well a lens performs in the "real world". You need user reports and truly EXPERT opinions to be sure. Also, the only way to truly know how good a lens is is to actually use it for a year. Winter,spring, summer, fall. That's an old adage I have found true. In the summertime (in N. America) a lens that is a bit lower in contrast is actually NOT a bad thing in many scenarios...in the winter, it will create dull,drab, low-contrast images in the real world.

In a totally related vein...look at orb9220's Flickr pages...the dude has page after page of good photos, many shot with what some might consider "modest" lenses. Just look at his pictures. Stats don't mean squat to him. He's done some AMAZING work with very modest lenses. And no--I don't even KNOW the guy...never even exchanged a PM or anything with him. So...it ain't just the "optics".

 

[bratkinson]

I have looked at a couple of MTF charts on lens reviews and I don't think I'll ever figure out how to read 'em. Probably don't need to, either. Instead, I read the rest of each lens review and consider the authors' thoughts on things like "look and feel" as well as things like barrel distortion, and perhaps a number of other factors I don't yet understand. Many of the reviews have comments from other readers and share their pros and cons about the lens as well. Even the buyer reviews at the major retailers sites can be useful, too.

Google-ing a specific lens brings up reviews as well as places they can be bought at. That's how I've done my research before I pulled the trigger and bought one.

 

[orb9220]

I know you Derrel tho never met you always had sound advice here. And have agreed with your real up-front no nonsense and helpful advice.

And tho reading test charts can be help for those that know how to interpret them. Many especially new to photography will have a hard time making sense of them. Or even actually understanding them.

As you pointed out much has to do with skill level and intimate understanding of their camera and lenses that they do have. I know those limitations and work within their capabilities or find a way around them. And always relied on a slew of others for their assessments in real world use. That and of course budget was the first heavy weight on my decision making.

Thanks for the kind words.
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