DSLRKIT Lens Focus Calibration Tool Alignment Ruler Folding Card (pack of 2)

I used this to calibrate a new Sigma Art lens in conjunction with the Sigma USB Dock Mount for Canon Lens. Worked brilliantly.Was tempted to knock off one star for lack of instructions (I didn't because of the superb value). It depends what your set-up is (camera make?, dock options?) but just covering the basic principles would be useful. The QR code in the middle does take you to their website where there are basic instructions: it would be easy enough to include a copy of those. Lots of good info online though.When calibrating: measure and align carefully. Do be careful that the vertical centre-piece _is_ actually vertical before shooting! Do use a tripod, mirror lock-up and delayed or remote release. For example at 40cm with a full-frame sensor and 50mm lens at f1.4 the dof is less than 5mm ... the more accurate and stable your set-up the easier the process is and the more reliable the results. Make use of green and purple chromatic aberrations that will appear in the side markings in your shots!All they need to do now is make a 'big brother' for longer focussing distances and wider lenses. At 10m with full-frame 50mm lens the vertical bit in the middle can just about be hit by my 5D spot meter, but a bigger version is needed for this focal length and for wide angle lenses.

Worked very well allowing me to calibrate all my APS-C lenses from 15mm to 300mm. Did not follow instructions prececely as I would have been too far away to even be in the same room for some of the telephoto calibration distances. Worked fine being closer, but not too close. Accuracy of my lenses is now spot on when using the camera's AF.Camera: Pentax K-5

Great simple kit to calibrate the focus point. Easy to use after checking out a few YouTube tutorial vids.

It's okay for calibrating shorter focal length lenses, say up to around 100mm. But considering the recommended calibration distances of at least 25* focal length (50* recommended by Canon) trying to focus anything over 100mm takes you into over 5 metre territory which I think is about the limit of this chart as it's quite small. Obviously if you're going to calibrate at 25* focal length this would be the equivalent of 200mm focal length. Forget about trying to calibrate your 300+mm lenses accurately as it's just too small for the purpose. Does work well though for shorter focal length lenses.There's plenty of numbers / lines / squares up either side of the chart to allow you to clearly see where your true point of focus lies.

I was hanving focus issues on my 70D so thought I'd try these as a cheap option, glad I did.These come flat packed then you fold these into shape like a mini Ikea. They are exceptional print quality on a strong but flexible card.You focus on the centre QR code, wide open aperture, then shoot. You should focus on 0. Of you're focus is behind or in front, micro adjust to the numbers. Easy.The only downside is setting up your camera square with the tool which can only be fixed with a rig. But for less than a fiver, these will get your camera and lens calibrated as close as you'll ever need. Bargain.

It wasn't until a month or so ago a friend of mine told me about fine tuning my lenses. I went online looking for the calibration tool. All the hard plastic versions were too expensive for something I would only end up using once or twice and simply didn't justify the prohibitive cost. Then I found this on Amazon. Decided that for the price, even if it didn't work, I'd not have lost too much money. On checking the full listing, it came with a spare too, bargain!It was delivered very quickly. Was east to set up but be sure to put it on a table or something flat and even then simply follow the instructions. I found out that all my lenses were slightly out, including my much loved telephone, a Canon L lens no less! Anyway, I have tested out their results and wow, amazing, definitely worth investing in if you're serious about your gear.

Struggled with this and it's a little frustrating that it didn't come flat. So when I put it together it wasn't level and being thin cardboard you can't correct it. Made the focusing troublesome bit got through it. Turns out my lens was out and since using a part of this, my focusing is better.

Easy to use. But you need the fine central lines to test lenses and the large central cut-away section has removed most of their width making it borderline unusable. Sadly the lines are wide where you don't need to see them and impossibly narrow where you do! See the photo. Shame as it's otherwise such a good device had the hole been better sized/positioned by the designers.