Extenders - Any good?

[Gill Blower]

I am thinking about buying either a 1.4x or 2x extender for my Canon 50D.The main lens I use is an EFS 18-200mm f3.5-5.6. I have heard conflicting views that the quality of the image can be affected and wondered if anyone has tried them out. If a member has any images to share that would be great so I can see what the benefits/drawbacks are.

Thanks for your help

[KEASLA]

i like them i have a sigma 1.4x main downside is if you have a lens that the converter will make it f8 or lower if so it will not auto focus on any camera apart from a canon 1D (not sure on other brands) but this does not count the new 1d x as that cant auto focus with a max aperture of f8 or lower

also on a side note a converter will not work on an ef-s lens only ef lenses

[Tom Gerrard]

Gill,

I have a Canon 2X which you can have a play with if you want. Rather than go into the pros and cons here it'll be better if you have a bash yourself and make your own mind up. There is much incorrect information going around regarding these converters, but I will say used 'sensibly', knowing their few limitations, I believe the pros certainly outweigh the cons by far. If you have a Canon camera I would also stick to the Canon brand - after all, would you put Lada wheels on a Ferrari?

Regards,

Tom.

[John]

An extender, or converter as it is often known, will magnify the image, lose some light, but also magnify any lens faults as well as introducing new ones.

To get the best results, buy a marque converter, choose a modest magnification no more than 2x and use it with high grade lenses. Prime lenses will giove better results than zooms.

An 18-200mm zoom is quite an ambitious design, so be aware that some of them are downright poor with converters. Try before you buy if you possibly can.

[KEASLA]

You are all missing what I have said a converter will not work on this lens as it is an ef-s lens only ef lenses will work

[John]

Why is that Keasla? Are converters not made to fit EF-S lenses?

[KEASLA]

Ef and ef-s lenses are a different fitting only 1.6 crop canon slr use them so anything under a 5d and I have never seen a converter for an ef-s lens and a quick google does not come up with anything but you can use an ef lens and converter on a crop body as I use a 1.4x I will show you at the next meet

[John]

Thanks for that, I'll be interested to see that on Thursday.

[Tom Gerrard]

Hope this helps.

cc.jpg (200.72 KiB) Viewed 8365 times

MF = Manual Focus.

Tom.

[PhilipHowe]

I asked Tom and Theo about these a while ago and the table Tom has posted is what was quoted to me. I went to a shop with my 70-200EF and 24-105EF and they both worked. I also tried my 18-55EF-S that came with my 350D and it was truly awful, It made it look like a toy camera lens, fringing at the ends and effectively produced a spyhole type effect, but I wanted to see for myself.

If you have an L series with IS, then I think it's worth looking at one, as you may only get around f5.6 (I think), but the IS effectively gives you two stops back, so a fully useable lens and converter. Other than that, my opinion is that it's not worth it (that's for the 1.4x or 2.0x Canon).

As it will degrade your lens in this way and may not even work, for the same money, there is someone on ebay selling 400 and 800mm barrel lenses which are fixed at f8 and are chinese made.

I know what the next comment will be, but as the converter will destroy the picture anyway.........

[Theo Dibbits]

Gill

I use a Sigma 70 - 200 f 2.8 (which is a nice bit of glass) and have the sigma 2x converter, which makes it a 140 - 400 f 5.6.
I am always disappointed with the results when using the converter.
Part of the problem is that in order to shoot handheld you need to increase the shutterspeed to 1/640 or 1/800.
Even in good light it means "jacking" the ISO up and my Canon D40 has poor high ISO performance.
Below are some images from yesterdays shoot. The light was fantastic so I got away with keeping it to ISO 400.
The first 2 are shot using only the 70 - 200 at 200 mm showing the original size and a crop.
The second 2 are actually at 318 mm and again the original size and a crop to approx the same size as 1.
The first crop shows more noise in the blue (which would be easy to fix) but is substantially sharper then the second one.
I am now seriously thinking of selling the converter. (any one want to make me an offer?? )

If I started again I would probably look at the Sigma 50 - 500 which Bert uses or the Canon 100 - 400 L

Theo

[Gill Blower]

Wow! what a fantastic response, thanks everyone for your comments. Tom, Thanks very much for the offier, I would like to give it a try if it will work with my lens - Jared doesnt seem to think it will.

See you all on Thursday,

Gill

[Tom Gerrard]

It will not work with your EFS 18-200mm f3.5-5.6. See table above. What I was going to do was bring a lens down with a 2x converter to put on your body to see if the quality was acceptable for you.

Tom.