cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

soft images after recomposing? 24-105

iphonemaster93
Rising Star

I'm about to go shoot cars at one of the biggest car events of the year in California and I don't want this event to be a hit or a miss for me, as it only happens once per year and I may not be able to go next year. With the 24-105, I find myself constantly getting soft images when I recompose. I normally zoom all the way in on a specific car part, focus with the single point AF, and then zoom out, take the shot, but sometimes as I'm zooming out, the car part becomes out of focus and the entire car, as well as the photo, becomes soft and sometimes even blurry as well. Am I just doing something wrong, or is that just how the 24-105 is? Because that never happened with my 17-55. I'm starting to think I should test a few where I move the single point AF around, don't zoom in at all, focus, take the shot, and see what happens. The event I'm going to, there will be cars doing burnouts and hard launches and I don't want to come back home with poor quality photos. Thanks! 

4 REPLIES 4

cicopo
Elite

That lens doesn't retain critical focus as you zoom to another focal length. You MUST refocus if you change focal length. Also based on personal experience at the track you must turn IS off if you pan a moving car.

"A skill is developed through constant practice with a passion to improve, not bought."


@cicopo wrote:

That lens doesn't retain critical focus as you zoom to another focal length. You MUST refocus if you change focal length. Also based on personal experience at the track you must turn IS off if you pan a moving car.


Yes, the IS system can get into a tug-of-war with the AF system, if either the camera or the subject is moving too quickly.  I fight that all the time whenever I'm trying to capture birds in flight. 

 

I've resigned to the following technique when time is short.  I typically leave the lens in MF mode, and the lens pre-focused to a known distance.  I also have the camera in continous shooting mode.  If I have time to switch to AF mode, then I will do so.  Many times it's point the camera, hold the shutter, and adjust the focus through it's range slightly.  I'll go from out of focus, to in focus, and back out.  I almost always wind up with a keeper by knowing the focus distance of the lens, and the range of adjustment.

 

Hopefully, cars will not be catching you by surprise, or leaving you with little time to capture an image.  There are different ways to capture images of moving cars, depending upon what type of motion blur you're looking for.

 

 

 

 

--------------------------------------------------------
"The right mouse button is your friend."

TCampbell
Elite

You should not "zoom" after focusing with the vast majority of zoom lenses.  

 

Some lenses are "parfocal" which means that if you focus the lens to any given distance and then zoom, the focus distance remains unchanged (you would not need to re-focus).  VERY VERY FEW photographic lenses on the market are "parfocal" (parfocal zooms are common in the video industry.)

 

For Canon, the lenses which are truly parfocal include:

 

  • EF 17-40mm f/4L USM
  • EF 16-35mm f/2.8L II USM
  • EF 70-200mm f/2.8L USM (note, this is the non-IS version.  The IS version is not parfocal.)

There are several other lenses that are nearly parfocal (meaning the focus doesn't change by much... but it does change.)

 

 

Tim Campbell
5D III, 5D IV, 60Da

ebiggs1
Legend

"I'm about to go shoot cars at one of the biggest car events of the year in California ..."

 

Can I assume these cars are not moving very fast?  If, yes, than you have all the time you need to get it right.  If it were me, I would use center focus point only.  Turn all others off.  Focus on the main most important thing and make it the main most important thing.  Use One Sot not AI-Servo (unless they are moving fast).

Also you can't use f4 or even f5.6 and expect to have a lot in focus.  Try for f8 or f11.  Use a middle of the road ISO unless you have great light then use ISO 100. 

 

I am not a fan of the "spray and pray" method of shooting. You really need to know what you are doing and set things correctly.  Spray and pray will fail you eventually.  And if you use RAW, like I do, you don't get many shots before the buffer fills up.  And you are shooting RAW, right?

EB
EOS 1DX and 1D Mk IV and several lenses!
Announcements
01/18/2023: New firmware version 1.1.1 is available for EOS R6 Mark II
01/09/2023: Help ensure your autofocus is properly aligned with a Canon Precision Alignment
01/03/2023: Welcome to CES 2023!
12/08/2022: New firmware version 1.0.5.1 is available for EOS C70
12/07/2022: New firmware version 1.7.0 is available for EOS R5
12/07/2022: New firmware version 1.7.0 is available for EOS R6
11/22/2022: New firmware available for EOS R3, EOS R7 and EOS R10
11/16/2022: We're thrilled to be ranked among the Best Employers for Veterans in 2022 by Forbes.
08/31/2022: New firmware version 1.1.1 is available for RF 70-200mm L IS USM
08/09/2022: New firmware version 1.2.0 is available for CR-N 300
08/09/2022: New firmware version 1.2.0 is available for CR-N 500
07/14/2022: New firmware version 1.0.1 is available for CR-X300
06/10/2022: Service Notice:UPDATE: Canon Inkjet Printer continuous reboot loop or powering down
06/07/2022: New firmware version 1.3.2 is available for PowerShot G7 X Mark III
05/31/2022: Did someone SAY Badges?
05/26/2022: New firmware version 1.0.5.1 is available for EOS-C500 Mark II
05/26/2022: New firmware version 1.0.3.1 is available for EOS-C300 Mark III
05/10/2022: Keep your Canon gear in optimal condition with a Canon Maintenance Service
05/05/2022: We are excited to announce that we have refreshed the ranking scale within the community!
04/26/2022: New firmware version 1.0.1.1 is available for EOS R5 C
03/23/2022: New firmware version 1.0.3.1 is available for EOS-C70
02/09/2022: Share Your Photos is back!
02/07/2022: New firmware version 1.6.1 is available for EOS-1DX Mark III
01/19/2022: READY FOR ANYTHING EOS-R5 C
01/13/2022: Community Update. We will be retiring the legacy profile avatars on 01/20/2022. Click this link to read more.