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big lie

Started Apr 4, 2015 | User reviews
goldsmith New Member • Posts: 2
big lie

i compared it's image with old screw-mount 135mm jupiter lens

it's maximum focal lenght is 130mm

if do not believe

examine it yourself

 goldsmith's gear list:goldsmith's gear list
Canon EF-S 55-250mm f/4-5.6 IS STM Canon EF 50mm F1.8 STM
Canon EF-S 18-200mm f/3.5-5.6 IS
Lens • Canon EF-S • 2752B002
Announced: Aug 26, 2008
goldsmith's score
2.5
Average community score
3.3
schmegg Veteran Member • Posts: 5,768
Re: big lie

goldsmith wrote:

i compared it's image with old screw-mount 135mm jupiter lens

it's maximum focal lenght is 130mm

if do not believe

examine it yourself

From 'The Digital Pictures' review of this lens ...

"The 18-200 is 87% as far away when framing this subject size - making its 200mm seem more like 174mm at its longest setting at this moderate distance. Regardless, the EF-S 18-200's focal length range is really nice."

Furthermore, this is not unusual for cheaper superzoom lenses.

J A C S
J A C S Forum Pro • Posts: 20,544
Re: big lie

At what distance?

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Formerly known as Just Another Canon Shooter

Great Bustard Forum Pro • Posts: 45,641
Probably focus breathing...

goldsmith wrote:

i compared it's image with old screw-mount 135mm jupiter lens

it's maximum focal lenght is 130mm

if do not believe

examine it yourself

...for a tightly framed shot.  At infinity focus, I bet it's a lot closer to 200mm.

p5freak Senior Member • Posts: 2,998
Re: Probably focus breathing...

Focal Length are always for infinity focus. If you shoot something close the lens will shorten its focal length. Every lens does that, even a true macro prime.

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Stupid is as stupid does - Forrest Gump

photonius Veteran Member • Posts: 6,895
Re: big lie

goldsmith wrote:

i compared it's image with old screw-mount 135mm jupiter lens

it's maximum focal lenght is 130mm

if do not believe

examine it yourself

This is normal, you find this with many modern internally focusing lenses, especially macro lenses, where at close focus the Canon 100mm macro becomes like 60mm or so.

Or the brand new 100-400 Mark II L lens (there was another thread). At minimal focus distance, it becomes 177mm !!  (at the 400mm setting). It's a compromise made for optical quality (who would have heard of a 18-200 mm lens in 1970), not extending too much, having a small optical group for focusing with AF, etc.  Many old lenses focus by moving out the whole optical group, that's not something you really want to do with AF.

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*** Life is short, time to zoom in *** ©

 photonius's gear list:photonius's gear list
Canon EF 100-400mm F4.5-5.6L IS II
Great Bustard Forum Pro • Posts: 45,641
Re: Probably focus breathing...

p5freak wrote:

Focal Length are always for infinity focus. If you shoot something close the lens will shorten its focal length. Every lens does that, even a true macro prime.

Sure, but some lenses more than others.  For example, I just learned the other day that it's quite the issue in the Nikon 70-200 / 2.8 VR II.

photonius Veteran Member • Posts: 6,895
Re: Probably focus breathing...

p5freak wrote:

Focal Length are always for infinity focus. If you shoot something close the lens will shorten its focal length. Every lens does that, even a true macro prime.

actually, not all lenses.  Old lenses often not, e.g. the old Canon FD 100mm f4.0 macro does not, it behaves very much like the single thin lens formula.

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*** Life is short, time to zoom in *** ©

 photonius's gear list:photonius's gear list
Canon EF 100-400mm F4.5-5.6L IS II
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