[JMitchell]

Wouldn't mind if someone could explain them to me! And whether I should buy them...
Seem like a good idea, but surely somethign so cheap can't be a good alternative....


Thanks

Jack M

[Dabhand16]

They are a cheap and efficient way of getting close to your subject. From memory, I think they work best with lenses under 50mm, and I also think the 'penalty' of the cheap price might be a smaller Dof at any given apature compared to a macro lens.

I'm not sure how they stack up against the close-up filters you can get like Foxesbrew uses occsionally, but as you are using the lens with no other optical mods, I suspect the extention tubes might be better in terms of IQ.

[orangepeel]

I've heard, here somewhere, they bring out the worst in your lens. Macro/micro lenses tend to be some of the sharpest you can get - very important for macro work.

Another issue u may find is you have to keep your aperture as large as possible if you want the AF to work. Minimum of F5.6 iirc. This is going to have a marked effect on your DOF.

Might be best to read the caveats...
THK Photo Products, Inc.

[JMitchell]

Thanks Graham and orangepeel, useful link btw! This is completely new territory for me, something I haven't come across for a while, all quite exiciting!!!
Seem decent enough, but orangepeel, do you mean by "bring out the worst in your lens" that they promote things like distortion, CA and [gulp] softness ?

[Dabhand16]

I guess just like other things in life, nothing is for nothing.

If you magnify images from any given lens, you will also magnify any weaknesses. So if there is a slight tendancy for a lens to (say) go soft in the edges, in normal use, you might not ever notice, but as soon as you magnify the image, any faults will be more noticable.

A bit like using a booster for an aerial. Yes, the output signal will be higher, but so will any interference you pick up.

Extrention tubes are still a good way of getting close. So is reversing the lens on the camera body by using a, wait for it.... reversing ring. This fits to the body and the lens can be screwed onto it using the filter thread.

[orangepeel]

^ wot he said

[JMitchell]

Hmm...I understand. However, I pose this question to you both:

Graham - also having the 18-70 Nikkor yourself, do you think 'tubing' it would reveal any gremlins within the lens?

Orangepeel + graham - what about the 70-300? I expect this would break down most likely? I know you can't really give a verdict, but based on specs?


Thanks a lot guys!

[Dabhand16]

Given that a prime is better than a zoom, there must be some inherent 'faults' in the 18-70, good though it is.

I don't have any idea of how much you may, or may not notice any problems with this lens, and even though they are mass produced, there will still be differencies between lenses, so whatever problems that one might produce might not be replicated by another of the same type.

I'm not sure how the 70-300 would react, or if the tubes would be strong enough to support the camera, especially if they were used together.

I think a prime lens of between 35 and 50 mm would be the best one to try, but if you don't have access to one, then the 18-70 is the only thing you have got to work with.

[JMitchell]

Well I'm thinking of biting the bullet and going for the nifty, so maybe they'd make a good combo?

[Foxesbrew]

I have no experience of tubes,but my reason for choosing filters was that no matter how may times i mount or dismount them to my camera, in the field, my sensor is not being exposed to dust.

[Dabhand16]

Originally Posted by JMitchell

Well I'm thinking of biting the bullet and going for the nifty, so maybe they'd make a good combo?

I think that will be a good combination

[Dabhand16]

Originally Posted by Foxesbrew

I have no experience of tubes,but my reason for choosing filters was that no matter how may times i mount or dismount them to my camera, in the field, my sensor is not being exposed to dust.

Fair point, FB, fair point.