You zoom in on your ring photo and only the front claw of the setting is sharp. The band behind it has turned to mush. This is not a focusing mistake. It is physics: close up, depth of field shrinks to a few millimetres, and no aperture setting will fix it on its own.
Focus stacking is the technique professional jewellery, watch and cosmetics photographers use to get around this. You take a series of photos, each focused slightly further back, then merge the sharpest parts of each into one image. The result is a product that is crisp from the nearest edge to the furthest. This guide covers when you need it, how to shoot a stack, which software or camera to use, and how to get the finished file ready for Shopify, Amazon, Shopee and Lazada.
Why Close-Up Product Photos Go Soft
Depth of field depends on aperture, sensor size and, most of all, how close you are to the subject. At life-size magnification (1:1) on a full-frame camera at f/8, the zone of acceptable sharpness is roughly 1mm deep. At half life-size it is still only about 3mm. A ring, a watch case or a lipstick bullet is many times deeper than that.
The obvious fix is to stop down to f/16 or f/22. The problem is diffraction: as the aperture gets smaller, light bends around the aperture blades and fine detail softens across the whole frame. As a rough guide, many cameras start to lose visible sharpness past about f/11 on full frame, f/8 on APS-C and f/5.6 to f/8 on Micro Four Thirds. So you trade a little blur in the background for a lot of blur everywhere. Focus stacking lets you shoot at the lens's sharpest aperture, usually f/5.6 to f/8, and still get full depth.
When you actually need it
- Jewellery and watches: almost always, especially rings, pendants with depth and angled watch shots.
- Small cosmetics and fragrance bottles shot at a three-quarter angle.
- Electronics details: ports, buttons, circuit boards and texture close-ups.
- Collectibles, figurines and model parts where buyers zoom in to judge detail.
You usually do not need it for larger items shot from a metre or more away (shoes, bags, apparel), for flat products photographed straight on, or for lifestyle images where a soft background is the point.
How to Shoot a Focus Stack
1. Lock everything down
The only thing that should change between frames is the focus point. Use a solid tripod, a remote release or the self-timer, and fix the product in place with museum putty. Switch the camera to full manual exposure, set a fixed white balance and use constant or continuous lighting (or a flash that recycles reliably at low power). Any change in brightness or position between frames becomes an artefact in the merge.
2. Choose your aperture and frame
Set f/5.6 to f/8 and ISO 100 to 200. Frame slightly looser than your final crop. Most lenses change their field of view slightly as focus moves (called focus breathing), so the software scales and aligns each frame, and the edges of the merged image get trimmed. A 5 to 10 per cent margin around the product keeps it from being cut off.
3. Set the start and end points
Focus manually on a point just in front of the nearest part of the product, then work backwards until you are just past the furthest part. Starting and finishing slightly beyond the product avoids a soft front edge or a blurred back rim.
4. Decide how many frames
Each frame's sharp zone should overlap the next. For most jewellery and small products that means 15 to 30 frames; a flat pendant might need 8 to 10. Too few frames leaves soft bands, too many just costs processing time, so err on the side of more.
5. Use focus bracketing if your camera has it
Turning a focus ring by hand 25 times invites vibration. Many recent cameras automate this with a feature called focus bracketing (Nikon calls it focus shift shooting). You set the number of shots and the step size, and the camera moves focus for you. Smaller step sizes give more overlap.
Where to Merge the Stack: Options Compared
You can merge in the camera, on a phone, or on a computer. Prices below are in US dollars at the time of writing, so check the vendor before buying.
| Option | Cost | Best for | Watch out for |
|---|---|---|---|
| In-camera compositing (OM System OM-1 Mark II and OM-5 Mark II; Canon EOS R7, R10, R5 Mark II and R1) | Included with camera | Quick, simple stacks with no computer step | Output is JPEG or HEIF, frame counts may be capped and the image is cropped slightly |
| Adobe Photoshop (Auto-Blend Layers, Stack Images) | Adobe subscription | Occasional stacks if you already pay for Photoshop | Prone to halos and soft patches around shiny highlights, and slow with many frames |
| Helicon Focus | Lite $115, Pro $200, Premium $240 lifetime (annual plans from about $30) | Fast, high-volume studios. Batch processing is in Premium only | Pick the tier with batch mode if you stack dozens of SKUs |
| Zerene Stacker | Professional Edition $289 one-time | Jewellery and gemstones where highlight quality matters most | The cheaper editions are licensed for non-commercial use only. Selling products means you need Professional |
| Phone apps (e.g. ReeFlex Pro Camera and Zeus Focus Stacking on iPhone; Open Camera focus bracketing on Android) | Free to low cost | Small sellers shooting on a phone | Small sensors are noisier. Use a phone tripod and plenty of light |
The licensing point is easy to miss. Zerene's own terms say Professional Edition is needed if you use the software to make money or to make images for sale, and product listings fall squarely in that category.
Fixing Common Stacking Artefacts
Halos around the product edge
A pale outline appears where a sharp edge meets an out-of-focus background, most visibly against white. In Helicon Focus, try switching between the depth map and pyramid methods. In Zerene Stacker, compare the PMax and DMap results. PMax usually keeps more detail, while DMap gives cleaner colour and tone. Clean up any remaining halos with the retouching brush, which paints detail in from a single source frame.
Ghosting on reflective and transparent surfaces
Specular highlights on metal, gemstones and glass move slightly as focus changes, and the algorithm can mistake them for detail. Diffuse your light more heavily so highlights are broader and steadier. On shiny products, retouch from the single frame where the highlight looks best rather than letting the software average them.
Soft bands or stripes
These mean there was a gap between two frames' sharp zones. Reshoot with a smaller step size or more frames. You cannot fix this afterwards.
Background replacement after stacking
If you remove the background, do it on the finished composite, not on the individual frames. Masking 25 slightly different frames produces uneven edges.
Getting Stacked Images Marketplace-Ready
Because each merge crops a slightly different amount during alignment, stacked composites often come out at odd, inconsistent dimensions such as 5,847 x 3,902 in one set and 5,912 x 3,944 in the next. Marketplaces want consistent sizes.
- Amazon: at least 1,000 pixels on the longest side to enable zoom (1,600 pixels or more is recommended), pure white background, with the product filling about 85 per cent of the frame on the main image.
- Shopee and Lazada: square 1:1 images, with 1,000 x 1,000 pixels a safe target for clear zoom.
- Shopify: a consistent square or portrait ratio across your catalogue, typically 2,048 x 2,048 pixels, so collection grids line up.
Export a full-resolution master from your stacking software first, then create the marketplace versions from that master. A batch tool such as PixelPrep can take a folder of mismatched composites and output correctly sized, padded square files for each marketplace in one pass, so the extra detail you worked for is not lost to awkward crops or stretched images.
Stacked images are highly detailed, which inflates file size. Compress the marketplace JPEGs, and keep the master uncompressed for future re-exports.
Focus Stacking Checklist
- Confirm the product is small or close enough that a single shot at f/8 cannot keep it fully sharp.
- Tripod, remote release, product fixed in place, manual exposure, fixed white balance.
- Aperture f/5.6 to f/8, ISO 100 to 200, frame 5 to 10 per cent looser than the final crop.
- Start focus just in front of the product and finish just behind it.
- Shoot 15 to 30 overlapping frames for jewellery-scale items, using focus bracketing if available.
- Merge with software licensed for commercial use, or in-camera for quick jobs.
- Zoom to 100 per cent and check edges, highlights and the band between front and back for halos or soft stripes.
- Remove the background on the composite, not the source frames.
- Export a full-resolution master, then batch resize and compress for each marketplace.
Focus stacking adds a few minutes per product, but for items buyers zoom in on, a photo that is sharp from front to back builds the confidence that closes the sale.