Macro shots with DSLR or iphone, extension tubes whats the wrap ? Options

[mickman]

Hi all,

I am interested in taking a few close up pix of my cars. I have a Canon 550D Digital SLR. I am under the impression that a set of extension tubes works quite well. they come in two flavors.. cheap ones that will disengage the AF (auto focus) so it's the good old method of manual focus which is no big deal considering most professionals use MF anyhow. Or the other option is a slightly more expensive set of tubes that allow AF.

I could really splurge out big time and buy a proper dedicated macro lens but I really don't believe I'll be shooting cars that often to invest in such a lens.

There's a fairly new product on the market now that allows you to attach a tiny extension lens to the front of your phone. This could be a viable option for someone not using an expensive SLR camera.
The quality is extremely good. here's a link if you are interested in such a device.. my friend uses one and he works in the film industry... so can't be so bad if he endorses it.

http://photojojo.com/store/awesomeness/cell-phone-lenses/

So, back to using extension tubes to shoot macro pix.. are there any members using these tubes and if so, what do you think of them.. is it really worth purchasing the AF version ? I believe the non AF version is approx. £8 whereas an AF version are around £40.