Will I lose autofocus with a 1.4x or 2x teleconverter on my new
EF 100-400mm f/4.5-5.6L IS USM Canon lens?
Also, will these teleconverters change my image quality at all??
Thanks!!
Posted by David Bostedo on November 27, 2007 at 3:14 PM
Hi Kyle - I don't own any of this stuff, but I've read about it quite a bit. The answer for autofocus is that it depends on which body you are using. Autofocus is disabled on the non 1-series bodies (20/30/40D, Rebel) for anything above f/5.6. 1-series bodies (1D, 1Ds, etc) will autofocus to f/8.
Adding a teleconverter to a f/5.6 lens will effectively make it an f/8, or f/11, so it won't autofocus on the non-pro bodies. It will autofocus with the 1.4X converter on a pro body.
There are some tricks with teleconverters where you can fool the body and try to autofocus by taping some of the pins. This will probably cause very slow autofocus though. You can search here to find more info.
As far as image quality, there will definitely be some degradation. How much I couldn't say, but it will be worse with the 2X than the 1.4X. Maybe someone here with more experience can comment on that.
Posted by Dan Borzynski on November 27, 2007 at 4:03 PM
I'd be really hesitant about using the 2x on the 100-400. I own the 70-200 f2.8 IS, which is about as good as zooms get and probably better than most copies of the 100-400, and there definitely a noticeable drop in image quality with the 2x.
For personal use, the combination should be fine, but based on my experience with the 70-200, I'd be hesitant to recommend the 100-400 and 2x for stock/marketing uses.
The other problem which immediately occurs to me is that your starting point at 400 mm with the 2x is f11. This is pretty slow for wildlife, if that is your goal. You could crank up the ISO but then you are looking at ISO 400-800. Are you comfortable with your camera's performance at these ISO's?
Posted by Steve Foss on November 27, 2007 at 4:11 PM
I've grappled with the 1.6 crop bodies/100-400L IS/TC issue off and on for nearly four years now.
For awhile, I did tape off the three pins on the 1.4 TC that kept the lens from reporting aperture to the camera. Autofocusing that way slowed things down quite a bit. IQ was just acceptable, and I have a very good sharp copy of the 100-400. I've had no trouble marketing images shot with the 100-400 to publications, but I would hestitate to try to market those with the TC because there was noticeable degradation. Some of those have sold well as prints, however, which is a different market with different needs than publication.
I quickly abandoned taping the pins because I read in several places that it can cause the autofocus motor to burn out quickly, and with not-so-good image quality and slow focus, it wasn't worth the risk for me. Because I don't trust my ability to manual focus in most situations (excepting close-up photography), my TC stays in the bag unless I borrow/rent one of the large fast supertele primes, which are much better candidates for the TCs.
In no circumstances would I recommend a 2x TC on the 100-400. I've experimented with the 2x TC and the 100-400 as well, and even with a competent manual focuser, IMO the IQ is just too bad.
If you do go the route of taping pins, mount the TC on the lens and lay the combo on a table, lens side down with the mount/TC sticking straight up toward you. Rotate the combo so that the row of TC pins is on top. Tape off the three pins on the left side with a small piece of tape. Then you're ready to go. Because of the taped pins, the lens can no longer communicate aperture to the camera, so the camera doesn't know that combo has a max aperture of more than f5.6.
I was just curious about it, I have a Rebel XT and at ISO 400 it is ok with 8x10s as long as there is no cropping. 2x doesn't seem to be a good idea at this point, I was just curious as to how I could get more zoom without throwing down a few grand on a 500 or 600mm lens.
Thoughts??
Thanks!
Posted by Steve Foss on November 27, 2007 at 4:19 PM
Kyle, I've had excellent luck with larger prints at iso400 with the 20D/30D and XT. In particular, noise is kept at a minimum of you look closely at your histogram and use exposure compensation or manual settings to refine your exposure by moving the histogram to the right on the screen. This is called "exposing for the highlights" or "exposing to the right," and involves overexposure on purpose. By slightly overexposing the image (but making sure you don't cut off any of the right side of the histogram and there are no "blinkies" on your screen, both of which indicate blown-out highlights), you preserved plenty of detail in the highlights but also allow more exposure in the mid- and shadow-ranges of the image, which is where noise generally resides.
Then, in post processing, you can darken the image a bit to make it look more natural.
If you go the other way, underexposing the image and then trying to lighten in in post processing, you'll get all kinds of nasty noise in the mid-ranges and shadow-ranges.
Without TCs, there's no way to increase the muscle of your 100-400 beyond what the 1.6 crop factor already does (effectively a 640mm lens with that conversion factor). While there certainly are times more focal length is needed to get a tight shot, a strong focus on developing good stalking skills and woodscraft will often put you in the zone when other photographers with longer lenses and fewer skills can't get the shot.
You could buy a 300 f4L IS and 2x TC to get to 600mm (960mm with the 1.6 crop camera conversion factor), but IQ with that combo will be worse than the 100-400's native IQ. You also lose autofocus, not to mention the flexibility that makes the 100-400 such a fine choice for wildlife/avian photographers on budget.
Sounds good Steve...I'll have to look into that. I'm also working on some blinds and the like that will allow me to get in closer on my subjects. There are many places around the Asheville area here in NC that the wildlife is quite tame as well, which will also help out a ton!! I get the new lens in the mail tomorrow!! I'm super excited about it! I really do appreciate all the info I've been getting off of this network, it's great!
One more question though....
Should I hold onto my 75-300mm lens or sell it to fund a better tripod or something? Is there anything that my 75-300mm can do that my 100-400mm won't be able to?
Thanks!!
Posted by Dan Borzynski on November 27, 2007 at 10:24 PM
What is your current tripod? Something like the Bogen 3021/3221 would be fine with the 100-400 setup.
The 75-300 is a nice lens to have if you don't want to be conspicuous - family gatherings or street photography comes to mind. I've kept my 28-135 specifically for cases where the bigger lenses will draw too much attention to me.
The 300 f4 with 1.4x converter seems to be a good combination with the cropped sensors and even with film. I haven't had the 2x on the 300 in a couple of years and not with the digital body so I can't directly comment on that, although I suspect that it has to be a far better combination than with the 100-400 and 2x.
My current tripod is an el cheapo from ritz camera, $30 unit and I couldn't even tell you the make....Quantaray maybe??
I will be needing a quality tripod sooner or later, esp. since my new 100-400 will have some heft to it for sure. I want to keep the price down below $150 if that is at all possible, I've been learning a lot about tripods on here thus far though and already have some in mind after reading some other current postings about tripods.
Posted by Steve Foss on November 27, 2007 at 10:41 PM
I've mentioned this on a couple of the related tripod threads going on now, but I've been using the Manfrotto 724B tripod for three years. It's 3.1 pounds (light in my book), black aluminum, has an integral ballhead and is rated to just under 8 pounds of gear. I've shot the 20D/30D/battery grip/100-400/flash off it all that time with the ballhead in all sorts of positions and it's been rock solid. Extends to a bit over 64 inches and is a bit under 20 inches collapsed. The new version, the 725B, has added a quick-release plate. Cost is about $115.
Discussion
9 repliesEF 100-400mm f/4.5-5.6L IS USM Canon lens?
Also, will these teleconverters change my image quality at all??
Thanks!!
Adding a teleconverter to a f/5.6 lens will effectively make it an f/8, or f/11, so it won't autofocus on the non-pro bodies. It will autofocus with the 1.4X converter on a pro body.
There are some tricks with teleconverters where you can fool the body and try to autofocus by taping some of the pins. This will probably cause very slow autofocus though. You can search here to find more info.
As far as image quality, there will definitely be some degradation. How much I couldn't say, but it will be worse with the 2X than the 1.4X. Maybe someone here with more experience can comment on that.
For personal use, the combination should be fine, but based on my experience with the 70-200, I'd be hesitant to recommend the 100-400 and 2x for stock/marketing uses.
The other problem which immediately occurs to me is that your starting point at 400 mm with the 2x is f11. This is pretty slow for wildlife, if that is your goal. You could crank up the ISO but then you are looking at ISO 400-800. Are you comfortable with your camera's performance at these ISO's?
For awhile, I did tape off the three pins on the 1.4 TC that kept the lens from reporting aperture to the camera. Autofocusing that way slowed things down quite a bit. IQ was just acceptable, and I have a very good sharp copy of the 100-400. I've had no trouble marketing images shot with the 100-400 to publications, but I would hestitate to try to market those with the TC because there was noticeable degradation. Some of those have sold well as prints, however, which is a different market with different needs than publication.
I quickly abandoned taping the pins because I read in several places that it can cause the autofocus motor to burn out quickly, and with not-so-good image quality and slow focus, it wasn't worth the risk for me. Because I don't trust my ability to manual focus in most situations (excepting close-up photography), my TC stays in the bag unless I borrow/rent one of the large fast supertele primes, which are much better candidates for the TCs.
In no circumstances would I recommend a 2x TC on the 100-400. I've experimented with the 2x TC and the 100-400 as well, and even with a competent manual focuser, IMO the IQ is just too bad.
If you do go the route of taping pins, mount the TC on the lens and lay the combo on a table, lens side down with the mount/TC sticking straight up toward you. Rotate the combo so that the row of TC pins is on top. Tape off the three pins on the left side with a small piece of tape. Then you're ready to go. Because of the taped pins, the lens can no longer communicate aperture to the camera, so the camera doesn't know that combo has a max aperture of more than f5.6.
Thoughts??
Thanks!
Then, in post processing, you can darken the image a bit to make it look more natural.
If you go the other way, underexposing the image and then trying to lighten in in post processing, you'll get all kinds of nasty noise in the mid-ranges and shadow-ranges.
Without TCs, there's no way to increase the muscle of your 100-400 beyond what the 1.6 crop factor already does (effectively a 640mm lens with that conversion factor). While there certainly are times more focal length is needed to get a tight shot, a strong focus on developing good stalking skills and woodscraft will often put you in the zone when other photographers with longer lenses and fewer skills can't get the shot.
You could buy a 300 f4L IS and 2x TC to get to 600mm (960mm with the 1.6 crop camera conversion factor), but IQ with that combo will be worse than the 100-400's native IQ. You also lose autofocus, not to mention the flexibility that makes the 100-400 such a fine choice for wildlife/avian photographers on budget.
One more question though....
Should I hold onto my 75-300mm lens or sell it to fund a better tripod or something? Is there anything that my 75-300mm can do that my 100-400mm won't be able to?
Thanks!!
The 75-300 is a nice lens to have if you don't want to be conspicuous - family gatherings or street photography comes to mind. I've kept my 28-135 specifically for cases where the bigger lenses will draw too much attention to me.
The 300 f4 with 1.4x converter seems to be a good combination with the cropped sensors and even with film. I haven't had the 2x on the 300 in a couple of years and not with the digital body so I can't directly comment on that, although I suspect that it has to be a far better combination than with the 100-400 and 2x.
I will be needing a quality tripod sooner or later, esp. since my new 100-400 will have some heft to it for sure. I want to keep the price down below $150 if that is at all possible, I've been learning a lot about tripods on here thus far though and already have some in mind after reading some other current postings about tripods.