Differences on using Extension tubes in different focal length zoom lenses

[zf.wild]

For my understanding, the main purpose of extension tubes is to reduce the minimum focal distance of a given lens.
Given the example of the E PZ 16-50mm, the E 18-135 and the E 70-350 G, is it possible to achieve a 1:1 magnification ratio in any of them? If so, is any of these lens capable of achieving better results?

 

[Killzen]

Extension Tube Magnification Calculator - Things Up Close

Use this Extension Tube Magnification Calculator to easily calculate the magnification of your camera lens and extension tube combination.

thingsupclose.com

 

[zf.wild]

Extension Tube Magnification Calculator - Things Up Close

Use this Extension Tube Magnification Calculator to easily calculate the magnification of your camera lens and extension tube combination.

thingsupclose.com

Interesting!

So in the example of the 70-350mm, which my research tells that has a maximum magnification of 0.23, if I add 2 extension tubes (26mm) it calculates the new magnification to 0.3, so a 1:3 ratio at the minimum focal distance. Is that right?

 

[UncleVanya]

Depending on your goals you might find this site helpful:

Extreme Macro Photography

extreme-macro.co.uk by macro photographer Johan J Ingles - Le Nobel is for budget-conscious macro photographers, and covers stacking, lenses, stages, lighting

extreme-macro.co.uk

Also bear in mind that with longer lenses adding a macro diopter lens onto your existing lens (Such as a Raynox DCR-150 OR DCR-250) will give far larger magnification without losing stops of light. See this calculator:

Using Raynox Adapters For Extreme Macro

Raynox macro adapters are not only by far and away the best way to start doing extreme macro, but you can even stack them and use them as tube lenses too

extreme-macro.co.uk

Using your 70-350 you should get roughly .6x - 2.3x with the dcr-150 based on your zoom setting and focus. (70mm gives the lowest magnification) Your working distance would be around 18-20cm.

 

[zf.wild]

Depending on your goals you might find this site helpful:

Extreme Macro Photography

extreme-macro.co.uk by macro photographer Johan J Ingles - Le Nobel is for budget-conscious macro photographers, and covers stacking, lenses, stages, lighting

extreme-macro.co.uk

Also bear in mind that with longer lenses adding a macro diopter lens onto your existing lens (Such as a Raynox DCR-150 OR DCR-250) will give far larger magnification without losing stops of light. See this calculator:

Using Raynox Adapters For Extreme Macro

Raynox macro adapters are not only by far and away the best way to start doing extreme macro, but you can even stack them and use them as tube lenses too

extreme-macro.co.uk

Using your 70-350 you should get roughly .6x - 2.3x with the dcr-150 based on your zoom setting and focus. (70mm gives the lowest magnification) Your working distance would be around 18-20cm.

Thanks!
That's clearer