CO

Not only is there diffraction at f/32 but it's also way past the sweet spot range for this lens. I used an EXIF data reader on photos #1 and #3. It shows that a Canon EF 70-300mm f/4-5.6 IS USM or a Sigma lens was used. LensTip.com does extensive lens testing. I downloaded the chart for their image resolution testing of the Canon lens. You can see that the lens is its best around f/4 to f/8 where it can resolve as much as 42 line pairs per millimeter. At f/32 it's resolving about 20 line pairs per millimeter.

The lens has its best resolution in the f/4 to f/8 range. At f/32 it's only resolving about 20 line pairs per millimter

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alfeng Loc: Out where the West commences ...

Although your specific question is about DOF ...

ONE reason that the pictures may not have the look you want is simply because of the lens you are using ...

I believe that there are manual (hollow "tube") adapters which will allow either a vintage Nikon/Nikkor or a Pentax/Takumar lens to fit on your Canon ... you can save money if you buy the adapter through eBay directly from a Chinese vendor.

Before you buy an adapter, be sure it will allow the lens to focus-at-infinity.

Check this site for potential film-to-flange compatibility ... http://www.bobatkins.com/photography/eosfaq/manual_focus_EOS.html

Most vintage 50mm lenses are affordable; and, THAT can be your starting point.

TriX Loc: Raleigh, NC

Just to clarify, when AA belonged to the “f64 club” those apertures refer to large format view cameras and that does not mean that ultra small apertures are good practice for 35mm. If sharpness matters to you, then diffraction negatively impacts images beyond f11 or even f8 on very high MP FF bodies. Why spend big $ for high quality lens and then limit its performance with diffraction at small apertures? You may think there is no adverse effect, but if you compare the same image at f11 compared to f22, it should be readily apparent unless you’re saving and displaying at low resolution.

Shel B

Several folks have mention diffraction as a problem at small apertures. I don't recall ever having a problem with diffraction unless there are light sources in the photo..such as shooting into the sun with the light playing off water or lights at night. Am I missing something? I'm not sure I even know what diffraction would look like except when shooting points of light. Can someone post a photo showing diffraction how shooting at a small aperture is a problem when there are no light sources in the photo? Diffraction, by definition is the bending of light. I think the idea of diffraction at small f stops is over stated. Am I wrong?

Linda From Maine Loc: Yakima, Washington

There are many good articles that help explain, just be sure to include "photography" in your search:

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/lens-diffraction-what-it-and-how-avoid-it

I don't have the photo examples anymore, but when I did a test with Panasonic G7 mirrorless and 14-140 mm lens, the image softness at f/22 vs f/8 was highly apparent (distant view landscape shot). I was quickly convinced

CO

I did some test shots once to see if I could see the effects of diffraction. I got this circuit board at a computer repair shop. I thought it would be a good subject for the test because it has a lot of detail. I had my camera on a tripod and took shots at f/11, f/29, and f/36. The lens was set at 72mm for all of the shots. I made a triptych of the images in Photoshop so it would be easier to compare. The images are getting softer with the smaller apertures. It's hard to say how much of this is due to diffraction and how much is because the lens is getting further away from its sweet spot range.

Upper image - f/11, Middle image - f/29, Lower image - f/36

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Image resolution at lens center for the Nikon 16-85mm lens that I used

TriX Loc: Raleigh, NC

Thanks for posting an excellent comparison for reinforcing the facts concerning diffraction with an actual demo - a picture is worth a dozen posts

Rich1939 Loc: Pike County Penna.

I've held off offering this but in all fairness to the OP I have to say it is apparent that the OP needs to work on technique as much as anything. learning to hold the camera steady and to squeeze off the shot will improve the results. And use a tripod when ever possible.

jakraig

Your question has a lot of answers and many people could take all day talking to you about it and still you might not feel comfortable, but, I'll try to help you a little along the way of what you can do. I apologize if I'm telling you stuff you already understand.

Looking at your three pictures, the first was not focused well anywhere, the second while focused on the eyes could have had a better exposure and I think I would have zoomed or gotten a little closer. It looks like the third picture the camera was moving when the shutter was released.

When you say good Depth of Field you would usually be talking about different depth of field depending on the subject. For instance, it is normal in portraiture to have a pretty shallow depth of field. Your second picture could be considered a portrait, perhaps it would have been good to turn the camera 90° to get what you really wanted. Shallow DOF is usually accomplished by using a lens that has a large diaphragm opening. A large F:stop (small number) would be something larger than say F:3.5, something like F:2.8, F:1.8, or F:1.4. Many inexpensive lenses start at an F:stop of 3.5 or even higher which make your choices much narrower. At F:1.4 if you are within about 20 feet then focusing on the nose, will make the ears, perhaps even the eyes out of focus. We would normally focus on the eyes and then the nose, much of the skin on the face will be just a little smooth. Most people like the effect. The background will be totally out of focus and be just a blur of color. That can be very nice but I expect that what you want is sharpness across the picture like what would be desirable in a landscape. What you want is not always easy to obtain without a little effort. With less expensive lenses when you are stopped down to F:3.5 even when you are wide open then that depth of field becomes longer and it is easy to get an entire face in perfect focus even when you don't want to. So, if long depth of field is what you want using an inexpensive lens may be just what the doctor ordered. Using an inexpensive lens in this manner has its drawbacks, you will not have the same options of controlling DOF and getting a really blurred background or Bokeh will be impossible.

Portraiture can be very demanding. Almost nobody thinks they look good in a picture but most think they look best when they are the subject. Using a large F:stop (small number) can really help you accomplish that because the wonderful shallow DOF means nobody else is in focus. It also should mean that although the eyes and lips are tack sharp the imperfections in the skin and hair are not. These wide aperture lenses cost more money than the smaller aperture lenses.

I will likely take some heat for what I'm about to say, but it reflects my experience. As a rule you won't need to use wide apertures for daytime landscapes and therefore can do a lot with less expensive lenses. While I really like my primes if you are willing to stop down a little a halfway decent zoom can give you excellent results in daytime landscapes. When you start shooting late in the day, in the golden hour you may have difficulty getting what you want however with a small F:stop (large number), this is when your tripod really starts to show off your camera and your skills.

Many people will tell you that diffraction will detract from your photo when you must stop down, that is have a larger F stop number, something on the order of F:16 to have a deep depth of field and there is some truth perhaps in that but not usually at F:16 and my experience tells me it is worse in brighter light. So, how to proceed? Well in full daylight you want to get the lowest ISO your camera or if using film use a slow film like ASA 64. With the newest Nikon cameras like the D810 and the D850 you can set your ISO down to 64 which will allow you to use more of the light without over exposing. Most other cameras will go down to at least ISO 200, many to 100. Second, for tack sharp landscapes I always use a tripod and a remote shutter release or a timed release. With a short exposure and low ISO you can handle some pretty bright light without having to go above F:16 or F:22, both of those openings will usually give you the depth of field you desire in landscapes. This is true especially if you are several hundred feet or more away from the subject. At that distance and F:stop your DOF will be measured in 10's of yards.

It gets a little more complicated if you are shooting moving water and want it to be blurred to show the movement because then you have to use a much longer exposure. In bright daylight you might be advised to use a neutral density filter. If you are shooting with a very wide lens, say wider than 16mm you have a different situation. The wide angle lenses usually have pretty good depth of field stepped down just a little so that the foreground and the distant objects will all appear to be in focus.

Shooting at the lowest ISO will help your apparent sharpness. We have a tenancy to blow our landscapes up to a large size, that will show all the imperfections there are pretty easily. At the lower ISO you get the benefit of apparent sharpness that comes from more dynamic range. Good dynamic range will help your picture look sharp as the dark spaces like shadows will not be black and the bright spots like clouds will still have great definition. Dynamic range on newer good quality cameras is better than even some medium format film. Increasing the ISO (larger number) will decrease your dynamic range and make the picture seem flater. Many newer cameras have over 14 stops of dynamic range which really makes your landscapes look almost like 3D.

Another advantage of shooting at a higher F:stops is that you get sharpness across the entire frame. Most decent lenses above about F:11 are sharp even in the corners.

I have shot sunsets and sunrise at up to F:40 without a diffraction problem but you will usually be better off at F:22 or below.

While I have vibration reduction lenses and they really are great, they won't beat tripod and remote.

BebuLamar

The OP asked how to get great DOF so I told him how to do it. I do not judge the artistic merit of the image nor giving recommendation on that respect.

JD750 Loc: SoCal

Good comparison. Nothing like an image to demonstrate the results of physics. Seeing is believing (for some not all).

TriX Loc: Raleigh, NC

With respect, it’s pretty clear from CO’s tests above and the graphs from DXOMark, that diffraction substantially lowers the resolution (especially for high resolution imagers) starting at f8-f11, and by f16, an excellent lens performs no better in terms of resolution than a mediocre kit lens. If resolution and sharpness is your goal, then anything beyond f8-f11 is a compromise. Now whether it’s worth it for increased DOF is a personal decision, but the degradation cannot be denied.

CO

Thanks.

JD750 Loc: SoCal

Your are most welcome.

Might I ask a few questions?

What were the shutter speeds for the 3 shots? What shutter mode was used? Was ISO fixed or variable? If variable, what were the ISO settings for the 3 shots?

CO

I used a Nikon D90 with Nikon 16-85mm lens. After I took the photos, I imported them into a Microsoft Word document for an article I wrote on the subject. When I save the images out of the Word document, it strips away most of the data. I will look for the original files. I'll post again with the information.