100-400L focusing issue

[Crash758]

I am having a very difficult time trying to get "sharp" photos with my 100-400 when shooting in low light/night. During the day, handheld, it is nice and sharp. So I know it is not the lens or camera. But in low light or slow shutters like 1/5 or slower - when it is on a tripod (gitzo 1228 with manfrotto ball head) and a remote shutter button - I have a real hard time getting good clear shots. Is it the lens being so long (at 400) that just the slightest wind or vibration causes the image to blur. IS is off when on the tripod, too, and I use mirror lockup.

When using the 17-40, I dont really have any issues. I just was curious if it is normally difficult to get sharp shots at night with the 100-400 or any other long lens with a very slow shutter speed.
Thanks.
Mike

[Roger_Cavanagh]

Mike,

I think most of the problem is the lack of light, but if you are suffering with tripod vibes, it is OK to use the IS. The IS should be off to avoid creating a feedback loop when the camera is perfectly, but with a litttle wobble the IS will help.

Also have you tried MF?

Regards,

[Jesper]

What camera are you using? Some camera models are not so good at focussing when there's not enough light. Have you tried manual focus? Do you get better results?

[robertwgross]

When I use my 100-400L lens, I have to think about several things. My D60 is not the fastest for autofocusing. When I get to the wide open limit of the lens, it may not be perfectly sharp. I might have some movement in the subject due to wind, and then there may be some camera shake.

Normally the lens mounts on the tripod, but to completely stop the camera shake, sometimes I mount the camera itself on one tripod and then balance the lens hood onto the top of another tripod. Then I have a shoulder bag full of camera stuff that I hang from the center shafts of the two tripods (for ballast). Lastly, I use a remote shutter cord. If all of that does not stop the camera shake, then nothing will.

---Bob Gross---

[scottbergerphoto]

I love the 100-400 IS L but it is well known to be a poor AF performer in low light and low contrast overcast weather. I added a 400 f/5.6 for that very reason. It focuses lightening fast in situations that the 100-400 just hunts. It is just a limitation of the lens.
Regards,
Scott

[Crash758]

Thanks for the replies. I see I may have to be a little more careful with wind, etc. I have not tried to use manual focus in low light - I figured it was the slight wind or wobble to the long lens when using a shutter speed a real slow shutter speed. I will try manual focus and maybe tightening down the hatches (so to speak) on the tripod and get it real still. Since the 17-40 seems to work great, I figured it was just the length of the lens. I also didnt realize the 100-400 was well known for low light focus issues.

So, I will try to use manual focus and maybe play around with the IS to see if it improves it. I take a lot of lighthouse shots in the evening/night and use the 100-400 to isolate the subject better and my results have been sligthly blurred which is not good.

By the way, I use the 10d and have not seem to had any of the focussing issues with it. It has been great and I have had it for about a year now.

Thanks again.
Mike

[defordphoto]

I love the 100-400 IS L but it is well known to be a poor AF performer in low light and low contrast overcast weather. I added a 400 f/5.6 for that very reason. It focuses lightening fast in situations that the 100-400 just hunts. It is just a limitation of the lens.
Regards,
Scott

You nailed it on the head, Scott. As some may know, or not know, you and I purchased our 400 f/5.6 lenses at the same time and we both concur on the results: The 100-400 is an excellent, very sharp lens. But, it is a bit slow on AF and it's low-light performance suffers. The 400 f/5.6 is a screamer. AF is faster and more precise. Photos are sharper out of the box, but with PS techniques, they produce comparable end-result photos. Not to mention that the 400 is much lighter than the 100-400.

[Scottes]

Scottbergerphoto & RFMsports nailed it, IMHO too.

Good luck getting that combo manually focused in low light. Neither the lens nor the camera are very good for manual focus.

If your tripod is too light try hanging a bag from the center post and fill it with rocks or water or something. The added weight will add stability.

[DAMphyne]

Just one of many reasons that I feel Canon is short-changing us by "Not" offering interchangable focus screens.
A split-image finder is the ticket for manual focus.

[Scottes]

Or a better mirror. The 20D is much better than the 10D for manual focus in my opinion.

Split image would be great, of course.

[defordphoto]

DAM/Scott: Those are camera specific issues. 1-series cameras offer thos options.

[Scottes]

Um, it's a camera-specific issue I was talking about...

[defordphoto]

Um, it's a camera-specific issue I was talking about...

Yes. Original poster was referring to posible lens issues. Not dissing your point, specifically, just clarifying it for the original poster who appears to be somewhat new.

[perfectpixel]

no one mentioned using mirror lockup for slow exposures such as 1/5.
you think that would help?
Not having seen examples, I wonder if the "sharpness" is really blurr due to vibration.
my $.02

[Cadwell]

The original poster said he was using mirror lockup....

[Crash758]

Yes, I use mirror lockup and either the timer or a remote release. I havent played around with it yet, but I will try some of the ideas in here. I love my 100-400 - when I bought it I didnt think I would use it so much. But it is very useful in isolating the subject. My 10d and all the lenses are sharp, just having a bit of a problem with the 100-400 in low light and night. But you all have provided some great advice which I will try.
Mike