Help with Canon 100-400 focusing

[pharris201]

Hi all-
I rented a Canon EF 100-400 F4.5-5.6 with a 2x Canon converter. I got it a week early to practice. The results are terrible so far. Nothing seems to be in focus and no matter what I do with aperture, manual focus, ISO seems to have any effect. All shots are on a tripod with the 2second shutter delay. I did a moon rise last evening and got the nice exposures (thanks to another post in DPS). When I imported into Lightroom and used Loupe to zoom in the edges were all blurred. I've shot daylight of perched birds at a distance and the same results. Even the roof tops were not tack sharp that I would have expected.

Can anyone help with some pointers that I may have missed.
Thanks.

[inkista]

2x Canon converter adds two stops to the max. aperture of any lens you use it with. So your f/4.5-5.6 lens became an f/9-f/11 lens when you put that tc on it.

Unless you have a 1-series pro body, that means your camera stopped autofocusing. All the non-pro bodies stop autofocusing when the max. aperture of the lens hits f/8. This is why Canon only lists the f/2.8L telephotos as being compatible with their 2x tc.

Also, a 2x converter tends to soften any lens you put it on and give you bad image quality performance--particularly zooms (vs. primes which can take tcs a little better). This is why most folks would recommend using a 1.4x tc instead.

I'd say, use liveview and 10x magnification if your body has it to manually focus, and realize that's probably about as good as it's gonna get. A converter in no way equates to actually having a longer lens.

[pharris201]

I'm using a T2i as my body. I noticed that the aperature was low F11 or so. The chart on the lens compatibility said there was not autofocus. I am OK with that part. I just needed to get long distance shots of wildlife for a vacation.
I will try taking the TC off and see if the images improve.

Would you recommend another lens that will work better with my body? The lens is from BorrowLens and they seem pretty reasonable about swapping.

[inkista]

Just me, but use the 100-400L without a tc, first. Hard enough to learn supertelephoto technique without throwing that particular hurdle into the mix.

You can always crop the image to get more magnification. The 100-400L is a superb lens, and probably better than anything else you could rent for the same price, and you won't need a special gimbal head to use it. You may even be able to handhold it, and you may not need a tripod--a monopod might be enough support for the wildlife usage you want it for. Make sure you're using the tripod ring, and that your support gear is sturdy enough to take the weight of the lens. A $30 Wal-Mart special isn't gonna cut it.

Without the TC, you should have a much easier time of it. Also, keep in mind the 1/focal_length rule: without IS, you want to use a shutter speed of at least 1/focal_length or faster; i.e., @400mm, you want to be at 1/400s or faster. With IS, you can go a stop or two slower, but probably not much more. Assuming you have good handholding technique.

Also, the 100-400L has the first generation of IS. That means you have to turn IS off if you're using the lens on a tripod. Having IS on will introduce motion blur with it.

[dave_lines]

my first thought was,, did you turn the IS off when on the tripod??? When I first got mine, I forgot to turn it off when shooting some birds,, took a while for me to figure it out, but after I turned it off,, worked fine. I agree with the tc,, take it off, It makes the shots soft, then if need be, zoom and crop on your computer.

[pharris201]

OK thanks. I'm going back out this evening and try the moon again. No tc no IS. They do include the tripod ring and my tripods are sufficient to handle the weight. Based on the advice I will probably return the 2x converter.

There are two events I am using the lens for. The first is a reenacment of the Bull Run battle later this week.Even with a media pass the platform is several hundred yards from the action. While I'm not looking for individual faces from that distance I do want to get some details. Then I leave for Yosemite and Monterey for some R&R shooting.

Thanks again for the advice and BTW Inkista - great gallery. Your work is awesome.

[gturner]

You just have terrible combo and the person you rented from should have dropped something in your ear before taking your money.

I would not recommend a x2 converter for much. If you are used to perfectly crisp L lens images, you will be dissappointed.

[pharris201]

No. Its my fault. I have a bad habit of logging onto sites and shopping myself without asking questions. I will suggest to them that they develop a database to see if what is being ordered will actually work. The converter can be sent back and I can save the $$.

[pharris201]

Hi all-
I took the advice from the posts and tried some more shots. In normal views they do look OK and the subject really pops out but In Lightroom loupe mode they seem noisy now. Maybe it movement maybe its focus. Maybe it is the way super-telephotos interpret images. Maybe its the nut behind the shutter.
If you all can look and tell me if what is going on I'd appreciate.

I've posted more on the site and switched the gallery to enable downloading the original file.

[sk66]

You have several possible issues here.
DOF: you were wide open and fairly close @ 400mm...The closer you are the shallower the DOF gets.
SS: you were at 1/100 and 400mm...too slow for most to hold effectively even with IS.
ISO: You were at 800. There will be some ISO noise with your camera and ISO 800 but easily cleaned up.