External auto focus assist light for mirrorless cameras is now availble

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This device is solving some of the problems, especially related to using mirrorless cameras in low light conditions, such as it is common in studio conditions, or other situations where the available light might be low. The main problem is that mirrorless cameras can’t use the external AF assist light provided by some flashes because the auto focus system cannot use the red light built in the external flashes, so the users must rely on the AF assist light which is built-in the camera. Unfortunately that light is often blocked partially or fully by the user’s hand, or by the lens.

This device can be used with almost any camera which has a built-in AF assist light. The only requirement is that the light sensor, which detects the AF assist light of the camera, must be installed by the user, so if you can do that then it can be used on your camera, regardless of brand or model.

The function of this device is simple

If the camera detects a low light situation and activates the built-in AF assist light then this device will detect that light and will provide the necessary AF assist light externally so that it will not be blocked but projected fully on the subject or the model.

The exposure or the white balance will not change because the light will be turned off before the exposure starts, the light is only on during the focusing process. Auto focus will be faster with less risk for racking and hunting than if you’d not use the AF assist light.

If this sounds interesting then you can order this device now. Please note that this is a DIY product, manufactured in low volume. It contains some 3D printed parts as well, and these parts are custom designed for the purpose.

Some technical information about the device

The used battery is a 23A type, which is a small but powerful 12V battery. Battery capacity is dependent the type and brand of the battery. Maximum current use of the device is 22mA. This means that the capacity is good for about 30 minutes to 2 hours of continuous light, depending on battery. This is normally enough for quite a large number of shots, depending on the speed at which your camera and lens can acquire focus. Focusing should normally not require more than 1-2 seconds, at least not with the Nikon Z7 and the 24-70/4 S lens, so even in the worst case, one battery should last for about one thousand images or more, better quality batteries will increase the number of images several times.

The LED which is used for the light is a high intensity (min. 18 000mcd) green LED, providing a range of about 8-10 meters, depending on the camera. The sensor which detects the camera’s built-in AF assist light is a high speed photo transistor. The delay introduced by the electronics is less than 2us, so it will not be noticeable during use and can be ignored. The size of the box is (L) 63 x (W) 25 x (H) 15 mm. 

It is important to attach the light sensor head in such way that maximum light from the camera's AF assist light hits the sensor when it is activated. This ensures maximum intensity of the AF assist light beam. Intensity is reduced if the sensor is incorrectly placed. Make sure also that the actual light beam emitted by the device is as centred with the lens centre as possible so that the light is covering the area where you want to get accurate focus. The adhesive putty supplied with the device allows installation almost anywhere on the camera body and also allows removal and reattachment if needed.

The light sensor head is 3D printed from PLA, which is environment friendly during the printing process as well as during use. If you wish you can use a different type of adhesive putty as long as it works together with PLA as well.

The universal sensor head is (L) 16 x (W) 10 x (H) 8 mm  so if you can fit that over the AF assist LED of your camera then you can use this device. The light sensor head is fixed to the main unit with a wire which is approximately 270 mm long. If you wish to have a longer one that can be arranged, just let me know. 

The AF assist light sensor and the main unit is attached to the camera and/or the flash using adhesive putty. The putty does not need any treatment, should not be mixed with oil or water or any other liquid. It is non-toxic and will not cause damage to the surface of the cameras, the flashes or other devices. It does not leave stain and can be easily removed. When stored, it can be put between two plastic sheets or a small plastic bag to protect it from dust.

The exposure and the white balance are not affected by the AF assist beam extender, assuming your camera works as expected. Tests of the device are carried out on two Nikon cameras only, the Nikon Z7 and the Nikon 1 V1.

Price and payment

The price for each unit is 62 EUR or 65 USD, depending on if you live in EU or outside EU. Shipping and handling costs will be added. At this moment this is 13 EUR in EU or 15 USD for shipments outside EU. I accept payments in EUR or USD only, no other currency will be accepted, orders paid in any other currency will be rejected.

Payments must be made through PayPal, no direct money transfer, checks or any other means are accepted. Prices and the terms are non-negotiable; if you think this is not acceptable for you or you think the price is too high, please don't buy it.

Note that due to transport regulations and restrictions, no battery will be included in the shipment. You have to buy the necessary 23A type battery locally.

How to order

If you are interested, please send me a mail using the contact information below. Please don't pay in advance before I confirmed that I have a device reserved for you.

After I received payment, I will need one work day to pack it and to ship it to you, using registered, traceable post. 

Please note that I will only sell this unit to buyers from Australia, Canada, USA, New Zealand, countries of European Union, Norway, Switzerland, Iceland, Liechtenstein, Jersey, Guernsey, Monaco, Aland, South Africa, Namibia, Botswana, Swaziland, Lesotho and Japan. Note that I make no exceptions made from this list.

Contact information

adapting(dot)camera at gmail(dot)com

Please note: the mail address above must be modified by you. You must replace the (dot) with real dots, the spaces before and after 'at' must be removed and the word 'at' must be replaced by @ sign. This is done to prevent internet robots from sending me spam mail.

After your modification the mail address will look like: axxxxxxx.cyyyyy@gmail.com

A final note about the AF assist light extender

This is a do-it-yourself product. No warranty or refund is given, other than that I guaranty I tested the device before shipping it, and I guaranty that it is working on my Nikon Z7 and V1 cameras when I ship it. I have no possibilities to test it on any other cameras since these are the only ones I have.


Currently I am making two types of this devices, the difference between them is only the light sensor head. One is designed specifically for the Nikon Z6 and Z7, the other is a generic type. You must indicate which one you will buy when placing the order because after shipping there is no way to change the head. Both types will work with any camera, but it is easier to align on the Z6 and Z7 if you have the model designed for the Nikon Z cameras. The generic type can of course also be used on the Nikon Z6 and Z7, so if you have more than one camera model or brand, then maybe the generic type is the best way to go, but that is a decision you have to make.