Tele converter v extension tube with macro lens

[Tormentil]

Neither. Go for the Kenko Pro 300 1.4x, you'll save a few quid and still have a quality TC.

[Geoff F]

Assuming your lens is a 'Canon fit' model it doesnt matter which make you purchase as long as it is also stated as 'Canon fit'.

But I'm still not convinced that a tube is the best way forward in your case. How close can you focus with your 70mm and how close can you physically get with that lens plus a tube.

I suspect that to get the magnification you require will mean getting within a few inches which could cause practical problems.

A TC will give you around a 100mm lens at the same distance you currently use. But I still think I would put that money towards purchasing a bigger macro lens which will work out better and probably cheaper in the long run.

But at the end of the day, only you can decide.

[Red Squirrel]

Thanks for that Tormentil. Will check that one out.

[WhiskyBottle]

Originally Posted by Tormentil

Neither. Go for the Kenko Pro 300 1.4x, you'll save a few quid and still have a quality TC.

You got there first

I've got a Nikon SLR, and a Sigma 105 macro. Neither the Nikon or the Sigma convertors would fit the lens because the rear element is set too far back.

Don't know if the same applies to the 70mm lens but make sure you physically try it before buying.

I used the Kenko Pro300 2x. Works great on the 105mm with no quality problems, also works well on my Nikon 300/2.8, but the Sigma 500/4.5 with the 2x is getting a bit iffy (probably lens rather than convertor)

You've still got to hold the thing still of course because macro is critical of movement/focus, but that's no different to using a 150-200 prime macro.

The 105x2 combo does autofocus (slowly), but I rarely use AF in the macro range.

[Red Squirrel]

Geoff am I getting this macro business wrong ? I thought that 50mm, 70mm, 100mm etc all magnify 1:1 but the higher the mm number means further away from the subject you can be to get the same magnification. Am I right or wrong? Crikey it's confusing.
I don't necessarily want to get further away from the subject but to magnify it more.
Thanks WhiskyBottle. I rarely use auto focus with macro either.
Can I just say thanks for everyone's input, I do appreciate it.

[Geoff F]

Firstly, also beware of the Canon converters which will only fit on certain Canon lenses.

With regard to magnification. It all depends on minimum focusing distances. For instance, using Sigma as an example, 50mm has a minimum of 7 ins; 100mm is 12 ins; 150mm is 15 ins.

So a 150mm at its minimum distance would give a bigger image than 50mm at 7 ins. But if we are also considering perfection of photography it could be argued that the bigger lens would give more distortion; although I think you would need close examination of a photo to see much difference.

In reality it probably just comes down to how close can you physically get. If you are only 7 ins away to start with how close can you realistically get without frightening the subject or causing a shadow from the camera under certain lighting conditions.

A 50mm with a 1.4x TC won't give you much advantage over a 100mm regarding magnification and the TC will cause some loss of light and degradation of the image. A new bigger lens will definitely give the best quality, but at a price.

But also consider, if you get a TC, do you have any other lenses which would benefit from its use. But remember that they tend to give poor results with the cheaper zooms.

The decision is yours!

[Red Squirrel]

Thank you for the explanation Geoff. As you say it's my decision and will have to give it more thought as I don't want to jump in and plump for the wrong one.