Have you ever looked at your photos and wondered why they're just slightly soft or out of focus, even when you thought you nailed it? 🤔 Could it actually be your lens causing the problem?

It's a common worry! Getting that perfect composition only to find it's frustratingly blurry is enough to make anyone think their lens might be broken. If you have that nagging feeling, there's a simple way to check: test your lens to see if it's focusing accurately.

This quick test can give you peace of mind that your gear is working correctly, or it can alert you to a problem so you can get it fixed. Ready? Let's dive in!

What Exactly is Front and Back Focus?

It's simpler than it sounds:

Front Focus: When the sharpest point lands in front of where you aimed your focus point, missing your actual subject.
Back Focus: When the sharpest point lands behind where you placed your focus point.

In both scenarios, the spot you intended to focus on looks slightly soft, while an area just before or just after it is tack sharp.

Is it Me or My Lens?

Now, let's be clear: most of the time, focus issues come down to user technique. Especially when shooting with a wide aperture (like f/1.8) and handholding the camera, even slight movements like breathing can shift your focus plane. Using the wrong autofocus mode or technique for your subject is also a frequent culprit. Often, improving your skills solves the problem! 😁

However, Sometimes It Is the Equipment.

Occasionally, your lens and camera might need to be "calibrated" – essentially, synced up to focus correctly together. Here's why without getting too technical:

Manufacturing Tolerances: Cameras and lenses are made within a certain acceptable range of accuracy. Your camera might slightly back focus, but still be within its tolerance. Your lens might slightly front focus, also within its tolerance.
The Combined Effect: When you pair a camera and lens that are both slightly off (even if acceptable individually), the errors can add up, resulting in a noticeable focus problem. This is why one lens might seem perfect on one camera body but off on another.
Quality Control: Although rare with high-quality lenses, sometimes a lens might simply be shipped outside the acceptable focus range. (This can be more common with cheaper lenses that undergo less stringent quality control).

Ready to Test? Here’s What You Need:

Forget complicated charts for this initial check. This simple method will reveal if there's a potential issue.

5 Batteries (AA or similar work well) 🔋🔋🔋🔋🔋
A Tripod (or a stable surface like a beanbag)
A room with plenty of natural light

A Quick Note on the Tripod: Please use a tripod if possible! Remember how even breathing can affect focus? Handholding can introduce movement that looks like a front/back focus issue when it isn't. A stable camera is crucial for accurate results!

Step-by-Step: Checking Your Lens Focus

Set Up the Batteries: Arrange the 5 batteries in a diagonal line on a flat surface. Each battery should be slightly behind and to the side of the one in front of it. Leave a small gap (about half a battery's width) between each one.
Mount Your Camera: Place your camera on the tripod. Position it looking slightly down at the batteries, aiming towards the middle one.
Camera Settings:
- Focus Mode: Use Single Point AF (or your camera's equivalent). You must select the focus point yourself. Don't use Auto Area AF where the camera chooses. Select the center focus point.
- Shooting Mode: Manual (M) or Aperture Priority (Av/A) is best. Avoid Auto mode.
- Aperture: Set your lens to its widest possible aperture (the smallest f-number, like f/1.4, f/1.8, f/2.8). This creates a shallow depth of field, making focus errors more obvious.
- Shutter Speed: Use at least 1/125s, but 1/250s or faster is better to eliminate any shake.
- ISO: Start with your lowest native ISO (e.g., 100). Increase only if needed for proper exposure with your chosen aperture and shutter speed. (Good light really helps here!)
Focus and Shoot: Carefully place your center focus point directly on the middle battery. Focus (wait for the confirmation if your camera provides one) and take a few shots to ensure accuracy.

Analyzing Your Test Shots

Upload the images to your computer – judging on the camera screen is difficult. Zoom in!

Perfect Focus: The middle battery (your target) should be the sharpest. The batteries in front and behind it should be clearly softer/blurrier. ✅
Front Focus: The battery in front of the middle one is sharper than the middle battery.
Back Focus: The battery behind the middle one is sharper than the middle battery.

Uh Oh! I Found Front or Back Focus. Now What?

If your test reveals an issue:

Test Other Lenses: Repeat the test with any other lenses you own, using the same camera body.
- If only one lens shows the problem, it's likely that specific lens.
- If all your lenses show a similar issue (e.g., all consistently back-focusing), the problem might be with the camera body.
Your Options:
- Return/Exchange: If it's a new lens and only that one is faulty, consider returning or exchanging it.
- Micro-Adjustment (In-Camera): Check if your camera has an "AF Micro-adjustment" or "AF Fine-Tune" feature (common on mid-range to pro cameras). This lets you digitally tell the camera how to correct the focus for that specific lens. You might need a calibration tool (like the Datacolor SpyderLensCal) for precision. Consult your camera manual!
- Send for Service: You can send the affected lens(es) and/or camera body to the manufacturer or a qualified repair center for professional calibration.

Hooray! My Lens is Focusing Perfectly!

Fantastic! If your test shows the lens is fine, but you're still getting soft images sometimes, it's likely time to focus on your focusing techniques. Mastering AF modes (AF-S vs AF-C), understanding depth of field, accurate focus point placement, and proper holding techniques can dramatically improve sharpness. 🎉

Pssssst - my course, Mastering Manual Mode, teaches you EVERYTHING you need to know!

Help! Nothing Looks Sharp!

If none of the batteries look sharp:

Did you ensure the camera confirmed focus before taking the shot?
Some lenses, especially budget-friendly ones used wide open (like older 50mm f/1.8s), can be inherently a bit soft. The middle battery should still appear relatively sharper than the others, though. Try stopping the aperture down slightly (e.g., to f/2.8 if you tested at f/1.8) and re-test if you suspect general softness.

Over to You!

Give this simple test a go if lens focus has been on your mind. It's a great way to either ease your worries or identify an issue so you can take steps to fix it. Happy shooting!