The authors report about the laboratory illuminations in their still relatively new luminescence laboratory and address the important questions about a potential signal-loss among the quartz or feldspar minerals if exposing the material du different, in parts very long durations of laboratory light. They quantify the relation of signal loss and duration of laboratory light exposure at different spots in their laboratory, and conclude that it’s mostly very minor, meaning without a statistically meaningful effect. Consequently, the here tested common ways of subdued light exposure during sample preparation are not of relevance for luminescence dating purposes. Furthermore, they precisely analyze the wavelength range of their laboratory illumination by doing spectral measurements.

The tests they do are of high importance and should motivate other laboratories which have not done such testing yet to follow this approach as it’s urgently necessary to exclude light contamination as a relevant source of luminescence signal loss.

The paper is of high relevance for the international community of trapped charge dating as it yields some very useful new information. The set-up of the experimental design, the overall structure of the paper and language style are of high quality and the contribution is scientifically sound. I personally recommend the paper for publication without improvements necessary.

I have only 1 question for discussion and I would be glad to stimulate a discussion here: Also if the here detected signal loss is not really relevant, still we are talking about a few percent in extreme. Can we do better? Or would the community say it´s not relevant at all?

This is a very nice study of a key aspect of the laboratory part of luminescence dating, the lighting conditions in the lab. Since material that will be dated with luminescence is light-sensitive it is important that lab light does not damage the samples and care needs to be taken to choose lamps with suitable intensity and wavelengths. There are a few but not many previous studies of luminescence lab lighting and this technical note by Frouin et al. is a valuable addition. They document and test the lighting in their luminescence laboratory with different filter combinations and measure the effect on selected quartz and feldspar samples for various time periods. The results show that the preferred light source + filter combination has a very limited effect on the samples and is well suited to luminescence lab work. The experiments are well set up and I particularly appreciate the detailed information on the light sources and that they test effects both on quartz and feldspar. The note and its conclusions would be of high interest to people working in luminescence laboratories.

Specific comments

I would like to have some more information about the samples used in the experiments. If they have been described elsewhere, a reference to that/those publication(s) would be sufficient. For the calibration quartz the paper by Hansen et al. (2015, Radiation Measurements 81) should be mentioned. Otherwise just brief information on natural dose, specification of the feldspar as K-feldspar already in the sample description, in addition to the site and rough age information presently stated.

It would also be interesting with some more discussion about the difference between quartz and feldspar. Currently the larger scatter in the K-feldspar results is attributed to fading, but is the larger decrease in dose with exposure time (compared to quartz) also due mainly or only to fading, or is there some component of higher sensitivity to the light’s wavelengths as well?

Technical corrections

L209 – replace “fold” with “foil”