Lens or tubes?

magpieant

magpieant

Suspended / Banned
Messages
2,043
Edit My Images
No
I am still toying with the idea of buying myself a dedicated macro lens.

So fgar i like the look of the Sigma 105mm - which i can get in the states for £200.

However, the more I read about extension tubes, the more I like them!!!

The set of 3 Kenko tubes are only £80 from onestop - and I reckon they would go nicely with my 1.8 nifty fifty - giving it macro like qualities.

Can anyone offer any advice on this? Am i better off saving cash for now and seeing how my macro photography goes using extension tubes - or should I delve in with 200 notes and get the Sigma ?

I have read lots of the previous posts on this matter and all seem to suggest that the tubes are really worthwhile.

Looking forward to reading your suggestions ..... cheers, Anth.
 
Get both :lol:
I bought the tubes first and used them with my 28-105 and 70-300, once I was satified that I liked macro enough I then bought the Canon 100 macro.
I would personally get the tubes first, you can get some very good results with them, and can still use them with the macro lens.
 
Yeah - I was thinking about going down that road.

Would tubes give me 1:1 with the nifty fifty?

read somewhere that tube length shoul = lens length - tubes would be slightly longer than 50mm so am I covered?

Anth.
 
You'll get more than 1:1 with a 50mm lens. The formula that states the ratio is tube length to focal length only holds if the lens is focused at infinity. In fact any lens is only at its given focal length when focused to infinity, tubes or not.

With a full set of tubes on the Sigma 105mm you'll get nearly 2:1 reproduction because the Sigma focal length is nearer 75mm at min. focus.

On a non-macro lens the shift in focal length isn't so great but there is still a shortening as the focal distance decreases, how much depends on the lens design.
 
TBH I am not sure, technical stuff is not my strong point, perhaps someone else can answer that.
It's not often that I use all the tubes together, your lens will be virtually touching the subject.
 
pxl8 said:
You'll get more than 1:1 with a 50mm lens. The formula that states the ratio is tube length to focal length only holds if the lens is focused at infinity. In fact any lens is only at its given focal length when focused to infinity, tubes or not.

With a full set of tubes on the Sigma 105mm you'll get nearly 2:1 reproduction because the Sigma focal length is nearer 75mm at min. focus.

On a non-macro lens the shift in focal length isn't so great but there is still a shortening as the focal distance decreases, how much depends on the lens design.
Click to expand...


I am not quite getting the techincals on that Yeah I know I can be pleb at times :D ) so in plain English, pleeze :D Would a 100mm dedicated macro lens ( Canon) benifit from a tube or tubes?
Ta
 
Chris

You'll be able to get a smaller FOV at a closer working distance with extension tubes, however be aware that your depth of field will also decrease with the more tubes that you use.

Remember when your field of view goes below the sensor size, you'll need more light on the target object.

Mr Perceptive
 
Okies.

I 'think' I just about understand the tecchie stuff.

Once again, the general consensus seems to be that the tubes would be a good idea for me to use.

Next question, given that it's my birthday on Monday (16th), would all the members of TP kindly place a few quid in the hat that i am now passing around in order to buy the aforementioned tubes for me ....... ?

I'll get my coat!

Anth.
 
Cobra said:
I am not quite getting the techincals on that Yeah I know I can be pleb at times :D ) so in plain English, pleeze :D Would a 100mm dedicated macro lens ( Canon) benifit from a tube or tubes?
Ta
Click to expand...

Yes, the only time you can run into problems with tubes is when the total length of the tubes exceeds the focal length of the lens as the min. focus distance becomes negative - ie inside the lens itself !

So 68mm of tubes on a 28mm lens won't let you focus on anything.

68mm of tubes on a 50mm lens will just about work but working distance will be very very small.

68mm of tubes on a 100mm lens will give a good balance between increased magnification and working distance.

Remember that tubes can be used on other lenses as well, often used for wildlife where the min. focus of the big primes isn't close enough.
 
Mr Perceptive said:
Chris

You'll be able to get a smaller FOV at a closer working distance with extension tubes, however be aware that your depth of field will also decrease with the more tubes that you use.

Remember when your field of view goes below the sensor size, you'll need more light on the target object.

Mr Perceptive
Click to expand...

Thats great I've got it! (finally :D ) Cheers :thumbs:


pxl8 said:
Yes, the only time you can run into problems with tubes is when the total length of the tubes exceeds the focal length of the lens as the min. focus distance becomes negative - ie inside the lens itself !

.
Click to expand...

Thanks for going over it like that it now makes sense Cheers :thumbs:
 
Nice one ok!

The tube set I am after consists of 3 tubes @ 12, 20 and 36 so I presume a combination of 36mm, 48mm or 32mm will be fine with the nifty fifty.

The other lenses I may use with these tubes would be (possibly) the kit lens 18-55 and a tamron 70-300mm which should be fine with all three tubes as they would only total 68mm. Is this correct ???

Cheers.

Anth.
 
100mm f2 is also brilliant with tubes, and is a good prime lens. And cheap!!
 
My tube(s) are now on order from onestop - went for the 3 set of Kenko ones (12, 26 and 30mm) - £76.99 - or might have been 79.99 !!!!

Anyway, I will keep you informed of their arrival and let you know what they are like.

Cheers for the help.

Anth.
 
You must log in or register to reply here.
Back
Top