topic Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items in EOS DSLR & Mirrorless Cameras

EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

alfred75 — Sat, 15 Jun 2024 18:38:12 GMT

I just bought the E05 R50 camera. I own an online business where I take pictures of mostly fishing lures, but also other smalls that I buy to resell. As far taking a picture of just one fishing lure or item goes, this camera does a great job. However, when I am trying to take a picture of two or more fishing lures together, or a fishing lure with it's original box, the camera will not focus on multiple items at the same time. It will focus on only one and the other(s) will be blurry. I have tried Macro, Group Photo, Manual Mode, Program Mode, Manual Focus, White Balance up and down and every setting on AF Area. I still have my old Canon PowerShot SX530 HS (bought about six years ago) and this has never been an issue with that camera. I am also finding that if I try to take a picture of fishing lure box, it will only focus on the end of the box closest to the camera, again, the back end of the box is blurry. Neither of these have been an issue with any camera I have had in the past, even ones when I first started this business 15+ years ago. Can anyone tell me why it's doing this and what I can do about it? I frequently need to take pictures of multiple items in the same shot so it simply doesn't work for me to not be able to do that. Please see the attached pictures of what it's doing. Thank you in advance for any help!

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Tronhard — Sat, 15 Jun 2024 20:25:11 GMT

Hi and welcome to the forum:

When a camera (or any lens) focuses, there is only one point from the camera forming a sharp focal plane (at right angles to the line of view): that is a physical characteristic and it's actually extremely thin.

When we think of things being in focus, that is to a fair degree the combination of our eyes and brain accepting that there is sharpness. This phenomenon is called Circles of Confusion, where things appear progressively less in focus as they move away from the true focal plane and they start to show blur, or circles where there are points of light.

What appears to be acceptably sharp is called Depth of Field (DoF) and it is conditional on several factors:
Shallower DoF happens with:

A subject being closer to the camera
A longer lens focal length
A wider aperture (i.e. f/stop value is lower e.g. (f/1.5 vs f/8)
A larger camera sensor

A greater DoF occurs with the opposite conditions. Usually, not all will be working in one direction.

In your case you are shooting objects that vary some distance from the camera, demanding a greater DoF, but are close - so that narrows the DoF you are getting. Compared to the PowerShot, you are using a much larger sensor which decreases the DoF for the same f/stop. We don't know your aperture value or focal length - which we need to know to be more specific. With two factors alone decreasing your DoF, this is contributing to your situation where you got more in focus with the other camera.

To help figure out the DoF for various settings, you can use a calculator:

A Flexible Depth of Field Calculator (cambridgeincolour.com)

You need to know the type of sensor and its crop factor:
For your PowerShot with a 1/2.3" sensor, the factor is 5.62 (or as close as possible for the calculator)
For your R50, with an APS-C sensor the crop factor is 1.6
You measure the distance to the a point about 1/3 from the closest point of the subject to the furthest and use that for the distance.
You need your lens focal length (as read from the lens)

To get a greater DoF, you can try the following:
Move the subject further from the camera
Use a larger f/stop - i.e. something like f/11
User a shorter focal length, if you have a choice
With those settings you may get a slower shutter speed, so using a tripod, bean bag or other steadying device would be necessary - or placing the object in a very bright environment
To apply those settings, you may need to go into manual focus mode.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

FloridaDrafter — Sat, 15 Jun 2024 20:39:14 GMT

Hello, Alfred!

As always, great information from Trevor.

To add to that, this sounds like a perfect use of the "Focus Bracketing" feature in the EOS R50, so start at page 265 of the Advance Users Guide. There are also lots of video tutorials on YouTube. A lot of product photographers use this method.

I'm guessing that the reason your PowerShot SX530 HS seems to get more of the subject in focus is because of the shorter focal length (4mm at widest angle) of the lens combined with the smaller sensor. These factors will exaggerate DOF even though it's the same, depending on distance. I'm not an expert on this theory so maybe someone can confirm or debunk this.

Newton

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Tronhard — Sat, 15 Jun 2024 23:29:37 GMT

Hi Newton:
You are correct 😊!

Depth of Field is influenced by a lot of factors: again for the in-depth background on this I will refer to the link on the article I wrote on this (thanks to my editors for their input!).
Equivalence: Sensor Size, Field of View, Focal Length and Aperture
Equivalence is not such an issue when sticking with one sensor format, but it becomes significant when comparing, or in this case, transitioning between sensor sizes.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

alfred75 — Sun, 16 Jun 2024 11:02:11 GMT

Thank you for the reply! That is a lot I didn't know about and some things I need to try to figure out. For what I am doing with taking pics of smalls, would I be better off getting a newer version of the Canon Powershot (and if so, which one?). Or does that camera have the same hurdle now a days? I definitely see an improvement in the crispness of my pictures (the single item pics that are working out) on the R50 vs the SX530 HS. I wonder if I would still see the better quality of picture the R50 gives me but also be able to take my group pictures of smalls as easily as I can with the SX530 HS with a different, newer model?

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

stevet1 — Sun, 16 Jun 2024 13:01:35 GMT

I read something the other day that has given me great pause.

It's not your subject that is in focus, it's what lies underneath a spot on the two-dimensional flat plane of your viewfinder screen.

I'm still trying to wrap my head around that.

Steve Thomas

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

deebatman316 — Sun, 16 Jun 2024 15:56:58 GMT

I would suggest stopping down the lens further such as F/8 or F/11. Since your Powershot camera had an approximate 5x crop factor. I had the same problem when I moved from APS-C to Full Frame. All I had to do was stop down the lens more from F/5.6 to anywhere between F/6.3-F/8 and the problem was solved. As my colleague (Trevor) pointed out the camera can only focus on one thing at a time. Stopping down the lens will allow more to be in focus even though the camera is focused on one thing.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Waddizzle — Sun, 16 Jun 2024 20:20:11 GMT

Note, theoretical plane of focus is not flat. It is actually curved like the surface of a round ball. The engineers design corrective elements within the lens to flatten the curved plane.

This is one reason why you may [see] people arranged in arc in large group photos. Or, the photo may be captured from a greater distance to capture all within the DoF.

What separates a macro lens from a conventional lens is that a macro lens comes closer to a flat, two dimensional plane of focus.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Tronhard — Sun, 16 Jun 2024 22:15:23 GMT

I note you have not specified exactly what lens and settings you are currently using and that would be helpful in helping you further. The R50 camera you now have is quite capable of taking excellent images, but you will likely need to adapt your technique.

If necessary, using a tripod or other steadying device, use an f/stop of at least f/8, move the image further away and use a longer focal length, and be prepared to crop the image.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

FloridaDrafter — Sun, 16 Jun 2024 22:33:24 GMT

@Tronhard wrote:

I note you have not specified exactly what lens and settings you are currently using and that would be helpful in helping you further.

Trevor, this may help. The OP is using the RF-S 18-45mm f.4.5-6.3 IS STM @ 18mm, f/5, 1/50th. The images have EXIF data (I use an EXIF plug-in for Chrome).

Newton

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Tronhard — Sun, 16 Jun 2024 22:37:33 GMT

With regard to technique. If you have not done so, I recommend downloading the R50 Advanced User Guide from THIS LINK and look on P265-9 for a feature called Focus Bracketing, which allows you to set the camera to take multiple images of objects that require a deep depth of field and combine them to make one very sharp image along the whole object.

Essentially, once you have configured Focus Bracketing, you focus on the closes point of your subject and press the shutter. The camera will take repeated images, shifting the focus toward the back until it cannot find something to focus on and will then stop. The resultant images are then combined into one image, sharp across the whole depth of the subject as a JPG file. For your purposes, this should be more than adequate.

For this, you will need a tripod and I would also recommend a shutter wireless remote release, or set the camera to shoot with a 2 or 10sec delay after pressing the shutter button to avoid camera shake.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

FloridaDrafter — Sun, 16 Jun 2024 23:30:47 GMT

@Tronhard wrote:

With regard to technique. If you have not done so, I recommend downloading the R50 Advanced User Guide from THIS LINK and look on P265-9 for a feature called Focus Bracketing, which allows you to set the camera to take multiple images of objects that require a deep depth of field and combine them to make one very sharp image along the whole object.

Trevor, that was what I suggested with my first reply, but I guess it went unnoticed by everyone or they just thought it was a bad suggestion, LOL!

Stacking is my choice for shooting displays of this nature, particularly the lure box which is at an angle unsuitable for just increasing aperture, IMO. When set up, it's no different than just taking the shot normally excepting you do need tripod and I always use the 10 second timer. The camera may delay a few seconds, depending on the number of shots, while it compiles the JPeG, but you can shoot Raw and compile in DPP 4 (my method). I'm not saying it's easy the first time as it may take some trial and error, it just depends on how good a grasp you have of DOF, like where it becomes unacceptably out of focus, so you need to plan your focal planes DOF overlap properly.

Newton

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

Tronhard — Sun, 16 Jun 2024 23:34:23 GMT

Thanks Newton. I have been working with limited resources temporarily and use windows. This is a great help.

Definitely I would increase the aperture to f/8 or f/11- I am not sure if one can go beyond that to avoid diffraction issues. Definitely think that the lens will work, but would recommend, for some subjects at least, the use of Focus Bracketing.

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

alfred75 — Mon, 17 Jun 2024 11:51:58 GMT

Thank you! I tried changing it to F/7 and F/8 and am having great results! This is exactly what I needed to do!

Re: EOS R50 Only Focusing On One Item In A Group Picture And Not All Items

alfred75 — Mon, 17 Jun 2024 11:53:18 GMT

Thank you! I changed it to F/7 and F/8 and am having the results I was looking for! I appreciate all your time in helping!