Constant length macro lens for Canon

I am looking for a constant length macro lens in the 100/105 mm range for my Canon EOS-450D in order to minimize the need for an adapter ring to my macro port.

To the best of my knowledge both the Canon 100 macro and the Canon 100 L macro have an internal focusing system that allows for constant length; does the same or similar feature apply to the Sigma 105 or the Tokina 100 ???

Thank you very much for your help !!!

Francesco

I am looking for a constant length macro lens in the 100/105 mm range for my Canon EOS-450D in order to minimize the need for an adapter ring to my macro port.

 

To the best of my knowledge both the Canon 100 macro and the Canon 100 L macro have an internal focusing system that allows for constant length; does the same or similar feature apply to the Sigma 105 or the Tokina 100 ???

 

Thank you very much for your help !!!

 

Francesco

I have the Sigma 105mm and it extends quite a long way (around 5cm) to focus close. Either of the Canons would probably be a better choice. Not sure about the Tokina.