EOS 5D Mark IV Poor image quality

[billwestermeyer]

Please excuse the rather basic question. I recently purchased a refurbished 5D mark IV from Canon USA. It is replacing my 6D mark I. I've been very disappointed with the image quality I'm getting from the camera and figured it was just an amateur photographer trying to figure out a new camera. But it really doesn't seem right, and I'm hoping to get some advice. I've attached an image I captured with the 5D and a Canon 100mm macro IS USM. ISO 400, 1/500, F 10, and the camera is about 3 feet away from the butterfly. I saved the image as a JPEG, but it is an unedited raw image. It seems pretty grainy to me. Does it to you? Should I have Canon check it out?

thanks

[p4pictures]

Can you provide a link to your RAW image? Evaluating a JPG means that we cannot see the same data as you. Furthermore different software applications convert Canon RAW images to JPG with different algorithms which can result in varied results and image quality differences.  

[wq9nsc]

Bill,

It looks to me like the camera is back focused a little bit in this shot.  3' away at f10 with a 100mm lens gives you under 2" of depth in focus and if you are looking at it very critically (like you would with a macro setup) then the "perfect" depth is even shallower.

With macro glass I typically use a single point for AF.  What was your AF setup and what was the focal point(s) on in your photo?

Have you calibrated the lens to the camera?  It is easy to do and necessary to ensure that the focus is spot on as controlled by the AF system. This is particularly important with a macro lens.  

The adjustment is in the camera under the AF menu.  Canon's standard instructions are to take three images of an object at your typical working range and then examine them in detail (typically using the larger computer screen) and then you decide from that whether to dial in a positive or negative offset to the AF for that lens based upon whether it is front or back focusing.  I modify the procedure and in one session take 3 shots each at 0, +1, 3, and 5 and then -1, 3, and 5 and examine them on the computer to determine what is perfect and if I need to interpolate between those points and make a second test.

Your 5DIV should produce excellent images at the ISO 400 setting used in that image.

Rodger

[billwestermeyer]

https://drive.google.com/file/d/12A_PexadrXVSm37sn0dtC8mkWUkxSOWj/view?usp=drive_link

As I look at these images, it seems that the leaf to the left is in better focus. I see that on others too. I have the focus point in the center though. Thanks for your help

[billwestermeyer]

Wow, How could i have missed calibration? I don't remember seeing that in a book on that camera. I'll get that done and see. In my reply to p4pictures, I wrote that the focus seems to be better on the leaf to the left. That may support your suggestion of calibration. Thanks! 

[March411 · Accepted solution]

Bill, do you have the Canon Digital Photo Professional (DPP) software. If you don't the link provided will get you there and it's a free application. It gives you the ability to look at your exact focus points which let's you know if you hit the subject matter in the way you intended. It also has some decent features for post production. If you already knew this sorry for the redundancy. 

• Tools
• AF Point Display Settings
• Show all AF points 

[wq9nsc]

You are welcome Bill and here is a Canon knowledge base article on it.  I would calibrate by lens, NOT by all, since each lens will be a little different.

https://support.usa.canon.com/kb/s/article/ART136230

Rodger

[Waddizzle]

I don’t believe calibration is the issue.  It could be, though.  You should rule out other factors first.  Your photo should not be taken as an example of how well the camera focuses with your lens.

 

There are other factors to consider first.  Factors such as DOF and camera movements, especially forwsrd and back.

If you have never performed a lens calibration before, be warned that it’s far easier to get it wrong than it is to get it right.  And almost no one gets it right on the first try.

A calibration should be a last resort, not a first option. 

[billwestermeyer]

I don't have it. thanks. I will check it out.

[billwestermeyer]

Thank you, I appreciate that warning and the DOF advice.

I realize using that lens as an example was probably not the best. It's the best lens I have, so I thought that would be the best example, but macros are a little different and tricky. I've tried more than one lens I put a link here for a similar unedited RAW photo taken 70-200 L IS USM at 121 mm,  ISO 160, 1/400 F8 taken at the same time. Its fairly sharp (with sharpening)  but not sure if it should be better.

https://drive.google.com/file/d/1S2s_3opDPzINaKXy3D6hS4gEu390yvzc/view?usp=drive_link

Thanks again.

Bill