70-200 f2.8L photos too soft

[uptheirons]

I am facing IQ issues with all photos I am capturing with my 70-200 on a 5dm4. Even when mounted on a tripod under good lighting conditions, I can't seem to get crisp photos. They come out pretty soft. I am not sure if its my technique or if there is some issue with the lens. I've never had any luck with this lens since I bought it but I always attribted that to my T2i. I sent it to canon for repair few months back and they told me there is dust on the glass and the mount has scratches, which I think is total BS as I hardly used the lens.

Even after coming back from the "repair", I still get very soft pics. I will test the lens for front and back focussing to see if that's the reason, but sometimes I seem to be getting ok shots. I am not sure if I am expecting too much out of this lens. Reading online many people attest to the quality of the lens. May be I got a bad one.

Any suggestions on how I can make sure its not the lens that defective?

Link to some raw files - https://photos.app.goo.gl/mXL3rNktA21e1f2P8.

Thanks!   

[jrhoffman75]

I say there is nothing wrong with your lens. The flowers are nice and sharp.

What you are seeing is depth of field effect..

A lens can only truly focus at one distance from the sensor, called the plane of focus.

Depending on the lens focal length, the aperture (f/stop), and distance from the lens there is a region in front and behind of the plane of focus where the eye can still consider the image to be sharp.  This is called the depth of field.

A 200mm lens focusing that close to the flowers will have a shallow depth of field.

https://photographylife.com/what-is-depth-of-field

[uptheirons]

Thanks for the response.  I understand depth of field. In fact I took pics at f4, f5.6 etc (let me see if I can find those and upload), but I am not satisfied with the pics. I forgot to mention that I was using center AF point and focussed at the stamen of the flowers in the pictures. But the stamen when zoomed in (100%, 200% in DPP4) don't look too sharp.

[Waddizzle]

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@uptheirons wrote:

Thanks for the response.  I understand depth of field. In fact I took pics at f4, f5.6 etc (let me see if I can find those and upload), but I am not satisfied with the pics. I forgot to mention that I was using center AF point and focussed at the stamen of the flowers in the pictures. But the stamen when zoomed in (100%, 200% in DPP4) don't look too sharp.

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Why didn't you manual focus?  Macro photography is something that you cannot rush.  You are on a tripod.  You can take your time to manually check focus, use shutter lockup, and even a remote shutter if you want.

A word to the wise.  Making AFMA corrections are easy to get wrong.  It will test you skill as a photographer.  It seems very simple and straightforward, which it ratty much is.  Just remember it is far easier to mess it up than it is to get it right.  

I recommend taking at least a dozen test shots, and calculating an average result.  Defocus the lens between each test shot.  Your test shots should show a general trend, which is why you want to take many shots and calculate an average deviation from being spot on.  

This means, of course, that you will want to take another series of similar test shots after making an adjustment to confirm the result of your changes.

[ebiggs1]

"But the stamen when zoomed in (100%, 200% in DPP4) don't look too sharp."

No kidding!  No lens does, don't do that.

"Making AFMA corrections are easy to get wrong."

Very true and most "L" lenses do not need it. Keep in mind AFMA does not make you lens one bit sharper. Nada, none! When it is needed, it is needed but make sure it is by doing a focus test. Not on a flower but on something like a yard stick.

If a lens is truly defective everything in the shot is OOF. Discounting camera motion of course. If it just needs AFMA than something in the photo will be in focus. Something either just in front of the focus point or directly behind the focus point.

[uptheirons]

Yes, manual focus sounds like a great idea. I uploaded only the macro photos but in general I am not too happy with my photos. Again I may be trying something that I can only master with lot of practice - like sports photography of my kids’ soccer and being really hard on myself 🤪. Some of my macro shots with lower aperture and shutter speed came out really good after I went back and checked them again. Maybe I am just being paranoid and need more practice.

I agree I need lot of patience and testing to see if I really need AFMA. Though I used -6 at the longer focal length and saw that the focus was almost perfect. Maybe it was a chance thing. But I will take lot of test shots just to be sure.

Thanks again for all the suggestions.

[Ray-uk]

Trying to assess sharpness by viewing at 200% is a complete waste of time because the software is just spreading the pixel information over a larger area than the natural resolution, there is no point in going above 100%.

[Waddizzle]

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@Ray-uk wrote:

Trying to assess sharpness by viewing at 200% is a complete waste of time because the software is just spreading the pixel information over a larger area than the natural resolution, there is no point in going above 100%.

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That is both true and not true at the same time.  I lot depends upon the size of your screen, so let's assume a 15" laptop. 

"Trying to assess sharpness by viewing at 200%, on a 15-inch 2K display, is a complete waste of time". Now, this is TRUE!  A 2K display is your typical 1920 x 1080 Full HD display resolution.

I use a laptop with a 15" 4K display.  The display has a resolution of 3840 x 2160.  When I open a photo in most appplications, the image is typically displayed "fit" to the size of the window displaying it.  

Zooming to "100%" means use one display pixel per image pixel. In other words, display the image at a 1:1 ratio between display pixels and image pixels.  When I change the image from "fit" to "100%", the display does not change very much.  I am sill looking at most of an 20MP image.

If I want to actually "zoom in" on an image for a magnified view, then I need to select 200% or more to see a "magnified" view.

[ebiggs1]

"That is both true and not true at the same time." 

Of course a better monitor is better. But at 100% you are still at pixel level at least in PS. I don't know what editor or viewer you use.

I have a 32" monitor and PS opens up a full Raw file at 25% from the 1DX.

If you increase to more than one 100% you are asking the computer guess. A Raw file can only reproduce an image at the resolution it was taken at. If you blow it up the image further than 100%, it will try to do it. However, what you see will be a best guess. Your computer will try to show the current pixels replicated outwards. Each pixel will be surrounded by replicas of itself. This will make your picture look blurry.  100% is 100%.

To the OP don't do that!

[Waddizzle]

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@ebiggs1 wrote:

"That is both true and not true at the same time." 

Of course a better monitor is better. But at 100% you are still at pixel level at least in PS. I don't know what editor or viewer you use.

I have a 32" monitor and PS opens up a full Raw file at 25% from the 1DX.

If you increase to more than one 100% you are asking the computer guess. A Raw file can only reproduce an image at the resolution it was taken at. If you blow it up the image further than 100%, it will try to do it. However, what you see will be a best guess. Your computer will try to show the current pixels replicated outwards. Each pixel will be surrounded by replicas of itself. This will make your picture look blurry.  100% is 100%.

To the OP don't do that!

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You're talking about pixel binning.  When I zoom to 200%, the number of pixels needed to display the image is doubled in along horizontal and vertical axis.  This means four display pixels, 2 x 2, are used to display one image pixel.  No image processing required.

I have a couple of 27" 1920 x 1080 monitors, too.  Images do look bad when I zoom past 100%.