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Reviews often speak of this lens as an excellent telephoto lens.
I guess I'm rather ignorant about the lens specs:
* Lens Type: teleconverter
* mounting_type: Canon EF
* Camera Magnify Power: 1 / 1
* lens_system_special_functions: Macro
* maximum_aperture_range: F/3.5
* Minimum focal length: 180 millimeters
* min_focal_range: 18.9 inches
* Focus Type: auto-focus, manual-focus
* Real Angle Of View: 13.5
* Weight: 2.4 pounds
* Item Display Diameter: 3.3 inches
* Length: 7 inches

Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
this be equivalent to?

"Dave" <> wrote in message
news:QPuWi.30341$aJ3.27338@trnddc02...
> Reviews often speak of this lens as an excellent telephoto lens.
> I guess I'm rather ignorant about the lens specs:
> * Lens Type: teleconverter
> * mounting_type: Canon EF
> * Camera Magnify Power: 1 / 1
> * lens_system_special_functions: Macro
> * maximum_aperture_range: F/3.5
> * Minimum focal length: 180 millimeters
> * min_focal_range: 18.9 inches
> * Focus Type: auto-focus, manual-focus
> * Real Angle Of View: 13.5
> * Weight: 2.4 pounds
> * Item Display Diameter: 3.3 inches
> * Length: 7 inches
>
> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
> this be equivalent to?

1.0

David J. Littleboy
Tokyo, Japan

David J. Littleboy wrote:
> "Dave" <> wrote in message
> news:QPuWi.30341$aJ3.27338@trnddc02...
>> Reviews often speak of this lens as an excellent telephoto lens.
>> I guess I'm rather ignorant about the lens specs:
>> * Lens Type: teleconverter
>> * mounting_type: Canon EF
>> * Camera Magnify Power: 1 / 1
>> * lens_system_special_functions: Macro
>> * maximum_aperture_range: F/3.5
>> * Minimum focal length: 180 millimeters
>> * min_focal_range: 18.9 inches
>> * Focus Type: auto-focus, manual-focus
>> * Real Angle Of View: 13.5
>> * Weight: 2.4 pounds
>> * Item Display Diameter: 3.3 inches
>> * Length: 7 inches
>>
>> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X
>> would this be equivalent to?
>
> 1.0
>
> David J. Littleboy
> Tokyo, Japan

.... because the lens does not zoom, so the ratio of its maximum focal
length to its minimum focal length is 1.

David

Dave wrote:
> Reviews often speak of this lens as an excellent telephoto lens.
> I guess I'm rather ignorant about the lens specs:
> * Lens Type: teleconverter
> * mounting_type: Canon EF
> * Camera Magnify Power: 1 / 1
> * lens_system_special_functions: Macro
> * maximum_aperture_range: F/3.5
> * Minimum focal length: 180 millimeters
> * min_focal_range: 18.9 inches
> * Focus Type: auto-focus, manual-focus
> * Real Angle Of View: 13.5
> * Weight: 2.4 pounds
> * Item Display Diameter: 3.3 inches
> * Length: 7 inches
>
> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
> this be equivalent to?

With cameras, the "X" is a ratio of the shortest to the longest zoom;
it's not a power of magnification like with binoculars and telescopes.

A 70-210mm zoom lens would be 3X (210/70). A 28-300 would be 10X
(approximately - 300/28 = 10.714285714285714285714285714286 to be
precise). The actual magnification will depend on the size of the
sensor (or film frame, if applicable).

As others have noted, since this is not a zoom lens, but a fixed focal
length, the actual zoom would be "1X".

Thanks all! How would I figure the minimum distance from the front of the
lens to the subject that would be possible to obtain focus?

"Dave" <> wrote in message
news:QPuWi.30341$aJ3.27338@trnddc02...
> Reviews often speak of this lens as an excellent telephoto lens.
> I guess I'm rather ignorant about the lens specs:
> * Lens Type: teleconverter
> * mounting_type: Canon EF
> * Camera Magnify Power: 1 / 1
> * lens_system_special_functions: Macro
> * maximum_aperture_range: F/3.5
> * Minimum focal length: 180 millimeters
> * min_focal_range: 18.9 inches
> * Focus Type: auto-focus, manual-focus
> * Real Angle Of View: 13.5
> * Weight: 2.4 pounds
> * Item Display Diameter: 3.3 inches
> * Length: 7 inches
>
> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
> this be equivalent to?
>
>
>

Dave wrote:
> Thanks all! How would I figure the minimum distance from the front of the
> lens to the subject that would be possible to obtain focus?

18.9 inches, according to your listed specs...

> "Dave" <> wrote in message
> news:QPuWi.30341$aJ3.27338@trnddc02...
>> Reviews often speak of this lens as an excellent telephoto lens.
>> I guess I'm rather ignorant about the lens specs:
>> * Lens Type: teleconverter
>> * mounting_type: Canon EF
>> * Camera Magnify Power: 1 / 1
>> * lens_system_special_functions: Macro
>> * maximum_aperture_range: F/3.5
>> * Minimum focal length: 180 millimeters
>> * min_focal_range: 18.9 inches
>> * Focus Type: auto-focus, manual-focus
>> * Real Angle Of View: 13.5
>> * Weight: 2.4 pounds
>> * Item Display Diameter: 3.3 inches
>> * Length: 7 inches
>>
>> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
>> this be equivalent to?
>>
>>
>>
>
>

"Dave" <> wrote:
> Thanks all! How would I figure the minimum distance from the front of the
> lens to the subject that would be possible to obtain focus?

Subject distance is measured from the film plane. For this lens, presumably
the "min_focal_range: 18.9 inches" spec refers to that. Subtract the length
of the lens (7 inches) and the flange to film/sensor distance (44mm, 1.5
inches or so), and you get about 10 inches.

Note that at that distance, you will be imaging an area 24x36mm with the 5D
or 15x23mm with an APS-C camera.

FWIW, the English on the US site is a bit better than that in the specs you
quoted.

http://www.usa.canon.com/consumer/co...5&modelid=7324

David J. Littleboy
Tokyo, Japan

>
> "Dave" <> wrote in message
> news:QPuWi.30341$aJ3.27338@trnddc02...
>> Reviews often speak of this lens as an excellent telephoto lens.
>> I guess I'm rather ignorant about the lens specs:
>> * Lens Type: teleconverter
>> * mounting_type: Canon EF
>> * Camera Magnify Power: 1 / 1
>> * lens_system_special_functions: Macro
>> * maximum_aperture_range: F/3.5
>> * Minimum focal length: 180 millimeters
>> * min_focal_range: 18.9 inches
>> * Focus Type: auto-focus, manual-focus
>> * Real Angle Of View: 13.5
>> * Weight: 2.4 pounds
>> * Item Display Diameter: 3.3 inches
>> * Length: 7 inches
>>
>> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X would
>> this be equivalent to?

Matt Ion wrote:
> Dave wrote:
>> Thanks all! How would I figure the minimum distance from the front of
>> the lens to the subject that would be possible to obtain focus?
>
> 18.9 inches, according to your listed specs...

Note: that distance is to the focal plane, not the front
of the lens. It does give great working distance to skittish
insects.

It is a great lens (I have one), but don't think it will
work as a short telephoto for action: AF is very slow.
The lens is impressively sharp, one of Canon's sharpest lenses.

Roger

>
>> "Dave" <> wrote in message
>> news:QPuWi.30341$aJ3.27338@trnddc02...
>>> Reviews often speak of this lens as an excellent telephoto lens.
>>> I guess I'm rather ignorant about the lens specs:
>>> * Lens Type: teleconverter
>>> * mounting_type: Canon EF
>>> * Camera Magnify Power: 1 / 1
>>> * lens_system_special_functions: Macro
>>> * maximum_aperture_range: F/3.5
>>> * Minimum focal length: 180 millimeters
>>> * min_focal_range: 18.9 inches
>>> * Focus Type: auto-focus, manual-focus
>>> * Real Angle Of View: 13.5
>>> * Weight: 2.4 pounds
>>> * Item Display Diameter: 3.3 inches
>>> * Length: 7 inches
>>>
>>> Zoom is often referred to as 6X, 10X etc. Can anyone tell me what X
>>> would this be equivalent to?
>>>
>>>
>>>
>>
>>

[Haroldo M. Magalhaes]

I've been using a 105mm nikon macro with a D300 with a 6" home made extension tube and preset the lens aperture to the desired aperture.

I'd like to know if I can use the 180mm macro and EOS Mark ll with a mechanical extension tube and pre set the lens aperture.

It seems impossible to me since the canon 180 macro does not have the aperture ring on the lens barrel, like other lenses.

Please, help me.