Why Telephoto Lenses Suck

[Biomech]

We all know that prime lenses are better and also that telephoto lenses have a "sweet spot" in the focal range that gives you the best image.

But seriously, what is the point when the shots from the ends of the range are so bad they are unusable? Why even bother making or buying such lenses. As you can see, this is mt 24-70mm Sigma lens. It's well built and the shots from mid range are very sharp and very colourful. But this lens is essentially only a 35-55mm if I want usable photos.


[url=http://www.flickr.com/photos/41731611@N03/5853913608/]

All at 1/1000 F/3.2. Rested on a table, same distance.

And the same can be said of apertures. It's generally accepted that the you'll get the best shots at around f/8.0 - f/11.0 on most lenses. So we go out buying f/1.4, f/1.7 etc because we need their low light capabilities, only to end up with a swamp of soft images.

[Biomech]

Same goes for my Tamron 70-200mm, although not as extreme. Each end is rubbish - possibly useless, at least from giving to a client point of view. Slap it at 150mm in the middle and it's pretty sweet.


Tamron 70-200 at 150mm by C-17, on Flickr

[SwissJon]

It's generally accepted that certain manufacturers are able to sell their products cheaper because their threshold for acceptable sharpness is lower than the threshold for the more expensive makes. Sure you can have good lenses from them that have better IQ than a threshold lens from a more expensive make, but in general, there are more lower quality lenses made by cheaper makes than more expensive ones.. Cheap lenses aren't just down to cheap plastic surrounds.. The glass is the most expensive part, it's all precision engineered, and even a few microns difference can make a huge differene to IQ and if you're throwing away only 5% of your completed lenses instead of 50% then you can afford to sell your lenses 45% cheaper. (Or something like that!)

Having said that, the final quality control is done by a human, not a machine.. It's perfectly feasable the human in question was having a bad day and let one or two bad lenses slip through the net. If your lens is still under warranty, take it back to the manufacturer and get them to check.. If it is below quality, they'll swap it out for you.

[Jim Bryant]

This is the exact reason why in 40 years of photography I haven't purchased any lens made outside of the canon factory. Sigma, Tamron and the rest.......their quality is not as good.

[scootermcq]

Originally Posted by Jim Bryant

This is the exact reason why in 40 years of photography I haven't purchased any lens made outside of the canon factory. Sigma, Tamron and the rest.......their quality is not as good.

I don't know.... Zeiss makes some pretty good stuff & are 3rd party

[Tzetsin]

Wow that is one nasty lens.

I have a 24-70 and 70-200 zoom from canon and i'll gladly use any focal length at any Fstop either one offers. I also own (but dont use) the 18-200 is kit lens and it produces perfectly usable images at any available configuration period. I've never seen or used a lens that looked like that.

That lens is fooked. take it back quick or run it over with your car to make yourself feel better.

[Biomech]

Cheap lenses aren't just down to cheap plastic surrounds

Oh absolutely, and those lenses weren't cheap either £400-£600. Short of going for, currently, unaffordable £4,000 lenses, I don't know what else to do. I always blame myself first off, but after working through every possible scenario, I found it was actually the lens itself. I have amazing Sigma lenses and very good Tamron lenses, but this is just crap!

I mean that second image, of the girl singing, that was shot handheld at 150mm 1/125 f/4.0 ISO 800 (Tamron 70-200 2.8), and even zoomed in is pretty sweet,

... in fact all in all, that with those specs and no flash in what was a blacked out room is actually quite impressive

[scootermcq]

Sure..... but here is a "kit" lens for half of what you paid fully extended at 200mm, wide open, iso 800 (so getting into what should give a poor image)



For what you are paying...... the heavens should open up and angels sing everytime you press the shutter release.

Originally Posted by scootermcq

[totally fakey girl voice]

This is totally like my real smile and not fake to just be fake because I don't want to be seen here right now with you, smile.

[/girl]

[Tzetsin]

Originally Posted by maxharvard

[totally fakey girl voice]

This is totally like my real smile and not fake to just be fake because I don't want to be seen here right now with you, smile.

[/girl]

no, your totally wrong. thats her "I had my teeth whitened last week and I totally want to show them off now" smile. lol