.19x at 135mm

[jann1033]

i couldn't find any kind of macro type ratio for my 28-135 lens and when i emailed canon they told me it was this....which leads me to wonder ....what is the macro ratio for my 28-135 mm lens? 1:5???( 19/100???)
thanks

 

[Charade]

 

[mhutchinson]

Jann,

The Magnification factor of the 28-135mm is 1:5.26. If you take my 50mm macro as an example, it's factor is 1:2 which is half size; with the full lifesize converter it makes it 1:1 (full lifesize).

Following that model a 1:3 would be 1/3 lifesize, 1:4 would be 1/4 lifesize and 1:5 would be 1/5. Another way to describe 1/5 would be 20% OR .20X (where 1:1 is 1X).

What Canon replied was the specific conversion for the lens @135mm it is slightly different at the 28mm end.

So .19X is 19% of lifesize (pretty close to 1/5). I really hope I didn't add to the confusion by getting winded.

Mike

 

[mabas9395]

Mike,

Do those figures change on a 1.6 FOV crop camera?

 

[mhutchinson]

I wouldn't think that the crop factor affects the figures. If you are capturing a 1/2 inch subject with a 1:1, it will be captured as 1:1. What will not be captured all the area around the subject on a camera with a crop factor, that gets cropped.

If you are trying to photograph a dime as fullsize, the lens will allow you to capure it as fullsize on the image sensor. This would be regardless of the crop factor on the camera whether converted to either 35mm (EF) or APS (EFS) associated film size.

Mike