Extender Consideration

For a serious photographer owning an EF100-400mm F4.5-5.6L lens to be used on an EOS 30D, is there any select advantage to owning both the 1.4X and 2X teleconverters for bird photography, or either for that matter?

Jonathan

I have a 100-400 and a Kenko 1.4X teleconverter. I also have a 30D, 40D and 50D. A few points to note....

1. If your lens is not long enough to pull your subject in close then adding a 1.4X teleconverter will place twice as many pixels over your subject as without. There may be a slight loss of IQ but, overall, you are likely to be able to resolve more detail in yor subject and crop less. I haven't performed any direct comparisons but my guess is that you'd get better results by using a 1.4X teleconverter, if you needed it. If, on the other hand, you had the 1.4X fitted but were often pulling the zoom back a bit from the 400mm end then you're really not helping yourself.

2. At the long end the 100-400 is already at f/5.6. f/5.6 is the limit for non 1-series bodies to AF properly within the specs. By adding a 1.4X teleconverter you reduce the aperture by 1 stop, so your f/5.6 become f/8. A 1-series camera will focus at f/8, but, I think, only with the centre focus point. AF is actually disabled altogether on a non 1-series body when your lens becomes slower than f/5.6. You can fool the camera by taping three pins in the teleconverter so that the camera does not realise the teleconverter is present. This allows the camera AF to attempt to function once more but it is operating outside spec and will not be as reliable or as quick, or may not work at all, hunting without ever locking onto your subject. Oddly, the centre focus point seems to be the one that is worse off with a teleconverter, with the outer diagonal focus points continuing to operate quite well. At least, that is true for the 40D and 50D. I think the 30D may cope a little better with the centre point and a teleconverter. I have tried photographing gulls in flight in excellent lighting and struggled with my 30D and 1.4X, but it did sometimes lock on. At the time I was only using the centre point to focus. I do not know whether the outer points would have been more successful. These days I pretty much never use the 1.4X for BIF, only perched birds or ground dwellers.

3. I have no experience of any 2X teleconverter, However, much as with the 1.4X teleconverter, you will be covering your subject with more pixels again, this time 4X as many. So once again you increase the detail and resolution captured for your subject. Many say that the IQ is diminished too much with a 2X teleconverter but , while that may be true when pixel peeping at 100%, I wonder whether it is true when viewing the final image at the intended size and viewing distance. The real problem now is that your f/5.6 lens becomes f/11 with the 2X teleconverter fitted. You can kiss goodbye to any kind of AF function, with or without taping pins, and as it is tricky to focus manually with crop cameras I think you will have a tough time to get perfect results. With a 40D or 50D you could use Live View and 10X magnification to tune in the focus perfectly, bu that is assuming your subject will stay still long enough. With a 30D and no Live View I think you'll struggle.

Long story short - with a 30D and 1.4X I think you may certainly be able to make use of the extra reach, but the 2X is pushing your luck a bit too far.

Good job by Tim above with the long answer. In short, you should do fine with the 1.4 provided that you work on a tripod. As you will be at very high magnification, you MUST be on a tripod. Ix-Nay to the 2X. I would also scrap the 1.4X for flight photography... And yes, you will need to focus manually with 1-4/1.4X TC combo unless you use the tape the pins trick (but then AF is exceedingly slow).

Tim and Art,

Thank you both, especially Tim, for that detailed, most informative response.

At 66, and a 35 year Canon FD freelance veteran, I decided to ease into the digital format as a near entry level student. I have used the former teleconverter incarnations, 1.4X, 2X-A and 2X-B, with my FD telephotos.

To be honest with you, when I recently bought my 30D, along with the EF 100-400mm, EF 28-135mm and an EF-S 10-22mm while on a trip to Colorado last month, I made the mistake of jumping the gun (obviously without thinking or advanced research) and bought a 2X for the 100-400mm lens. The camera shop in Denver didn't have the 1.4X - so..............., I thought I would get the 2X.

Is there an EF fixed focal length telephoto that this 2X will function with that would provide acceptable results? If not, I may be able to return this and order a 1.4X.

Art, I just bought your Digital Basics and ABP II CD to get jump started in this new arena.

Kind regards,

Jonathan

I use the 2X with 300 f2.8 with 40D and am happy with the results. Good luck.

Keep in mind adding a converter will slow down the AF The 1.4X will be slow and the 2.0X painfully slow !!!

JP not many lenses take to the 2.0X like the 300 2.8 !!! Even with the converter the image quality is amazing !!!

The 2x would work well with all the quality teles in Canons line up. I use the 2x with my 400f2.8. Find Artie using the 2x in his 600mm to good effect. It goes well with the 300f2.8 as well.

Sorry but with the 30D the 2X will only work with 2.8 or faster lens so the 600 is out. When Artie is using 600 with 2X it is with 1D body.

Thanks for bringing it up JP Just assuming a Pro body was being used !!!

I have a 100-400 L IS and find the 300 f/4 L IS sharper and lighter and works well with a 1.4x TC. So unless you want a 300 f/2.8 (which I also have and think is superb), the 300 f/4 is my lens of choice when I want to travel lighter. I use the 300 f/4 on a 30D with a 1.4x, then on a 1DII I use both the 1.4 and 2x TCs, and it works well. AF does slow down, but it is still very good.

300 f/4 +1.4x image: http://www.clarkvision.com/galleries...962.b-700.html

Roger

Hi Jonathon,

re:

Is there an EF fixed focal length telephoto that this 2X will function with that would provide acceptable results?

The 300 f2.8 and all of the f/4 super-telephotos can make great images with the 2X TC provided the operator knows what they are doing... And even with an f/4 lens and a pro-sumer body you can make sharp pix with the big lenses but you just have to focus manually. Linda Robbins was the champ at that. She was one of the first to go to digital--the 30D, and made great images with that, the 500 IS, and the 2X TC.

If not, I may be able to return this and order a 1.4X. Art, I just bought your Digital Basics and ABP II CD to get jump started in this new arena.

Excellent plan. Now study!

Thank you to all for your kind considerations and teaching support!

Regards,

Jonathan

No problem. One more thing to add - Since getting my 50D I very recently discovered just how soft my 100-400 is at 400mm and f/5.6. The difference in sharpness between f/5.6 and f/8 is significant. The lens does have a reputation for this behaviour so it comes as no surprise to me. I have calibrated the lens to the camera and I know I am not suffering from poor focus, just a soft lens.

If you add a teleconverter to a lens that is producing soft images then you get somewhat larger but still soft images. The sharpness/softness may be acceptable if you can fill the frame and have no need to crop, but if you are already struggling to make your subject a worthwhile size, and plan to crop, then I suggest you avoid f/5.6 (before adding the teleconverter). This means that instead of shooting at f/5.6 (becoming f/8) you will be better off shooting at maybe f/8 (becomes f/11). This will obviously have impacts on ISO and/or shutter speed choice but it may be a sacrifice you have to make to get adequate IQ.

Tim,

Thank you for that additional instruction. My notebook is filling up fast.

Jonathan