Do I need to return this Lens? Or What am I doing Wrong?

[Cheryl Flory]

My daughter fell in love with my Tamron 90mm macro. So I made her a great deal on it, and replaced it with the Tamron 180mm.

I have been shooting the 180mm, but haven't gotten a sharp image yet!
Yesterday I found a honeybee which didn't make it back to its hive before the frost hit and thought for sure I could get a sharp image on a non-moving subject! But as you can see below, I still couldn't. What else can I do? I got the lens from B&H so I guess I could still return it if necessary.

For the horribly image below I shot this still subject indoors,
mirror lock-up,
live view to manual focus and it looked very sharp in the camera.
manual exposure settings,
even tied the remote shutter cord tot he tripod leg to make sure it wouldn't move.

Canon 40D
Tamron 180mm macro
2.5"
F32
ISO 800

[Ed Grella]

Cheryl, What shutter speed did you use on this capture?

[David Sime]

Cheryl,
Your info says that you were shooting at a distance of 2.5 inches. The minimum focus distance on the Tamron 180mm is much longer than that. Could this be your problem?

[Cheryl Flory]

I did have extension tubes on. but I was not that close.
I did use a ruler to measure on subsequent images to make sure I was at least 8 inches from the subject. can you be too close if you can focus and it is sharp in the view finder??

perhaps it was just too long of a shutter. I was outside today and did a faster shutter, and it was a bit more sharp.

[Cheryl Flory]

David, how do you find the info on the distance? If that was the problem, that certainly would be an easy fix.

I was also having difficulty focusing on the wall from about 4 feet away. Is there a maximum distance too?

[Roman Kurywczak]

Hey Cheryl,
At that SS if your tripod isn't a rock......you can have problems. if this was shot outside.....wind could have moved the bee even thoug it was impercievable to the eye. I do think the MFD of the lens is around 12 inches but will check.....and they don't perform very well at distance.....although with that focal length 4 foot should be OK. Try using live view and zoom in (usually the + button) to check the critical sharpness. I am starting to use it more for stationalry subjects. In a final case.....place a newspaper or magazine on a table.....and take a few test shots. There will be falloff even at f32 and the distance to subject/angle to subject will all play a role in sharpness.......this will also give you an understanding on DOF for macro. Remember to use live view when focusing in this test......perhaps even after you do one through the viewfinder for comparison. Hope this helps resolve the issue.

[Cheryl Flory]

Thanks, Roman. Yes, I used live view +10X to focus for the bee shot, and it was indoors so there was no wind.
I think I am expecting too much from this lens. Perhaps just because it says it can shoot to f32, doesn't meant that you should.
I just shot some more shots outside, with faster shutter. with and without extension tubes, and from a farther distance. These photos came out sharper. So, as expected, the problem is behind the camera, not in front of it. I just have to learned the limits of this lens.

[John Chardine]

Hi Cheryl- Try the exact same image but use flash as your main light source- set camera to Manual and dial in say 1/250s at f32 and let the flash light the subject. That should eliminate camera movement as a variable. As Roman mentioned, at f32 you will get some softening of the image due to defraction.

I assume the image above was from a RAW with no resampling and no sharpening.

[Cheryl Flory]

Thank you, John. I will try that.
Yes, the image was from RAW with no adjusting or sharpening.

[Steve Maxson]

Hi Cheryl. There are some good suggestions above for you to try. A contributing factor to softness, as mentioned above, could simply be diffraction due to shooting at f/32. Some folks swear by shooting at f/32 - I swear at it! :) I have a Canon 180 mm macro and shots taken at f/32 are consistently unacceptably sharp to my eye. Even f/22 is a little soft. I would suggest taking a series of shots at different apertures to see if your lens is sharp at say, f/16. Shooting this lens at f/32 with extension tubes may be a bad combo. I recently took a series of images at f/22 using a 100 mm macro plus extension tube and flash. None were critically sharp. When you use mirror lock are you also using a cable release?

[Ed Grella]

Most auto focus cameras won't focus on a plain wall, they need some type of contrast (corner, switch, window frame etc...) for the sensor to lock on to.

[Ken Childs]

Cheryl, the Diffraction Limited Aperture on your camera starts at f9.3 so just to be sure, follow Steve's advice and start at f8. If you can't get anything sharp at f8, then you know there's a problem.

[Cheryl Flory]

Thanks, Ken. will try that.