Extention tubes vs macro lens

[aayling]

I am wanting to get into a bit of macro photography and just after some info on the disadvantages of extension tubes compared with a dedicated macro lens?

Thanks

[Schmenz]

i bought macro tubes, and really stuggled with them. although mine were cheapies with no connection to the tubes from the camera. just bought a dedicated macro lens and i love it.

ive leant my tubes to snowA and ill see how he goes with them!

[OzzieTraveller]

G'day Adam

There are two things here - the designed-for use [if that's the right term] for extension tubes vs the use of a dedicated lens esp for close up photography

In any focussing closer than infinity, the lens assembly has to be moved away from the focus-plane. Normally the lens focus-screw mechanismm does this, but it can only go so far [else it would fall out of the camera body]. If you insert an ext'n tube between camera body & lens, you can focus closer than before

Tubes can be used with any camera lens - be it a "kit" lens or a dedicated "macro" lens - although these days you can get 'simple' tubes that just extend, vs 'complex' tubes with full metering & focussing electronics built-in

Wheras a 'normal' say 100mm camera lens will close-cocus to maybe 50cm then stop, the dedicated macro lens will have a double-helix focussing mechanism to permit it to focus up to maybe 20 cm, and at that distance, you will be viewing the subject at about 1/2 life size

If you want to get to life size or 2x life size, then you need to use an ext'n tube on the back of the macro lens as well

Another aspect of the dedicated macro lens is the design of the optics - they will be better tailored for close focussing and the small apertures required for Depth of Field. The average SLR lens of 50-100mm size will go from about f2,8 to f22, maybe f32. A dedicated macro lens will go to f32 - f45 - f64 - maybe even f90
[I have used lenses of f128 in years long gone ... tho with 35mm film, the best I had was f64]

Hope this helps a bit ...
Regards, Phil
ps: are you any relation to Bob A from canberra ??

[aayling]

ps: are you any relation to Bob A from canberra ??

Don't think so.

[Speedway]

I started out taking macros with a set of close up filters that my father gave many years ago, I had only used them once with my Zenit. I dragged them out again when I got my 400D I found the IQ dropped off severely with them but I got a few good shots. I then got a cheap $15.00 set of manual tubes, with these I managed to get closer but the DOF was non existent. I then got a set of AF tubes and started to get some good shots with the kit lenses, about 12 months later I got my 90mm Tamron and I regularly use the tubes with this lens to get even closer. The point is a set of AF macro tubes is a good place to start as they will not go astray if you decide to get a dedicated macro lens later.