Need help on Close-up filter

[Liang]

I wish to buy a close-up filter.
Which lens should I use to get better close-up picture?
Canon EF50 F1.8II, Canon EFs18-55 or Canon EF28-135IS ?

[Jon]

The 50 f/ 1.8. You'll get better image quality (and more predictable magnifications, due to common zoom lens design characteristics) with a close-up lens on a fixed focal length than on a zoom. If, on the other hand, you want more range of magnifications, you'll want to use it on a zoom. You could always buy a 72 mm close-up and step-up rings to use it on the other two.

[Roger_Cavanagh]

Liang,

The close-up filter won't give you much in the way of extra magnification when you use it at focal lengths under 50mm, so using your zoom from 50-135 is the most sensible thing to do.

I've some info here (http://www.pixelpixel.org/helpinfo/18_500d-1.stm) that shows the different magnficiations you get from the different focal lengths for the Canon close-up filters.

Regards,

[Liang]

Jon & Roger,

Thank you for the advice.

Very good info from the link provided by Roger.

Regards,
Liang

[robertwgross]

If you hang around here long, you will find that Roger's parents didn't raise any foolish children.

---Bob Gross---

[drisley]

I'm a little confused by that chart.
For example, on the 135mm lens, the 250D apparently offers better magnification than the 500D. So, wouldnt the 250D be a better choice? :?:

[Roger_Cavanagh]

I'm a little confused by that chart.
For example, on the 135mm lens, the 250D apparently offers better magnification than the 500D. So, wouldnt the 250D be a better choice? :?:

You have interpreted the chart correctly, but you must remember that the 250D only comes in 52mm and 58mm diameters, so it may not be large enough to fit a particular lens. For instance, my 135/2 takes a 72mm filter and the 24-70L needs 77mm.

It's a good idea to buy the largest possible size and use step-up rings for smaller diameter lens.

Another difference between the 250D and 500D is max working distance 250mm vs 500mm, which may be a factor in deciding between the two.

Regards,

[drisley]

Thanks Roger. I've been thinking of getting the 500D for my 135F2L.
Do you have any pictures to show that you taken with that combo?
Does max working distance mean you can be up to 500mm away from the subject?

[Jon]

Yes. Canon names them by the max working distance. The more common diopter values would be +2 for the 500 and +4 for the 250. And you'll have comparatively little difference in working distance from max. to min. with those close-up lenses in place. They won't overlap in coverage, that's for sure!

[khiromu]

My understanding is that for shorter focal length, extention tube works better than close-up filter. For longer FL, it's the other way around. But I may be wrong..
Thanks
Hiromu

[Roger_Cavanagh]

My understanding is that for shorter focal length, extention tube works better than close-up filter. For longer FL, it's the other way around. But I may be wrong..
Thanks
Hiromu

If you are talking about magnification, then you are right. With extension tubes magnification is a function of the ratio between focal length and the length the of e-tube. 50mm lens and 50mm of tubes gives a 1:1. Whereas with close-up filters, the longer the lens the greater the magnification - 0.91 with the 500D and 400mm.

The downside of e-tubes is that the working distance is very small, which makes them not very good for shooting bugs and flys 'cos they get scared off.

Regards,