topic Re: 70-200 f2.8L photos too soft in EF & RF Lenses

70-200 f2.8L photos too soft

uptheirons — Fri, 07 Aug 2020 23:02:47 GMT

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!

Re: 70-200 f2.8L photos too soft

jrhoffman75 — Fri, 07 Aug 2020 23:54:58 GMT

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

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 01:07:42 GMT

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.

Re: 70-200 f2.8L photos too soft

Waddizzle — Sat, 08 Aug 2020 02:38:50 GMT

@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.

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.

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 04:03:40 GMT

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.

Re: 70-200 f2.8L photos too soft

Ray-uk — Sat, 08 Aug 2020 10:36:42 GMT

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%.

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 14:58:22 GMT

True. Not sure what I was thinking.

Re: 70-200 f2.8L photos too soft

ebiggs1 — Sat, 08 Aug 2020 16:33:18 GMT

The link you have does not contain any Raw files. Just jpg with all the exif data stripped.

What exactly do you see wrong with this shot?

It looks pretty darn good ot me. "...they told me there is dust on the glass ..." Unless it is severe, dust on the lens will not reduce IQ.

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

If your lens took that photo, there is nothing wrong with it. You might let me have a look at the actual Raw file.

Re: 70-200 f2.8L photos too soft

ebiggs1 — Sat, 08 Aug 2020 16:42:39 GMT

"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.

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 16:54:55 GMT

I agree. Some of the pics of my son shooting soccer ball had the focus in the front. So I suspected the lens was front focusing. I think the problem was that he was moving towards me and the camera had trouble locking the focus. I will perform more controlled experiments before concluding that’s it’s the lens.

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 16:57:46 GMT

Just saw your previous post. I did upload the raw files but I think google photos converted them to jpg. How do I upload raw files on this forum? I tried that but the site complained that they are too big.

Re: 70-200 f2.8L photos too soft

ebiggs1 — Sat, 08 Aug 2020 17:16:29 GMT

Yes they would be so that is out. You need something like Dropbox.

However form the sample, I did get to see in PS, your lens looks just fine. Don't go beyond 100% in viewing. That is a critical viewing level for sure. If you shoot Raw format none of your camera settings are applied to the Raw file. Always do a lens correction and a small amount of sharpening. Less is more. I always do a levels adjustment in PS, too. But that is mostly it.

There are similar adjustments in DPP4.

Re: 70-200 f2.8L photos too soft

uptheirons — Sat, 08 Aug 2020 17:21:22 GMT

I do shoot only raw. It’s possible google photos stripped out all the meta data.

Thanks for assuring me that the lens is ok 😃. This thing has been stressing me out.

Re: 70-200 f2.8L photos too soft

Waddizzle — Sat, 08 Aug 2020 17:58:22 GMT

@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%.

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.

Re: 70-200 f2.8L photos too soft

ebiggs1 — Sat, 08 Aug 2020 19:51:56 GMT

"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!

Re: 70-200 f2.8L photos too soft

Waddizzle — Sat, 08 Aug 2020 20:01:49 GMT

@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!

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%.

Re: 70-200 f2.8L photos too soft

ebiggs1 — Sat, 08 Aug 2020 20:17:28 GMT

OK then you are not actually viewing at 100% pixel level. That was my point.