The Tartan Ribbon or Further Experiments of Maxwell’s Disappointment/Sutton’s Accident
Elia Roldao
Round 1
Reviewer 1 Report
Comments for author File: 
Comments.pdf
Author Response
Answers to referee 1
We would like to thank the reviewer for the useful comments.
Images 1,2,3 changed to Figure 2
But was this a collaborative work? Therefore, Maxwell can be considered a co-author?
Maxwell seems to have asked Sutton to assist him with taking the photographs, but there is no record of any knowledge exchange between the two, therefore we would not call Maxwell a co-author. We changed: ‘how this collaboration came about’ to ‘how the contact between Maxwell and Sutton came about’
I suggest discussing more about other optical properties (e.g. dispersion, refractive index) of this glass and clarifying the lens's impact on the UV absorption.
We added: In [3] we discussed whether it is possible to generate a colour picture based on recording through density filters, but did not discuss the influence of a camera lens system on the transmitted electromagnetic radiation. A lens system consists of glass lenses and an iris which transforms the incoming light into an image in the plane of the recording device, either plate, film or detector. This is easier said than done. The different wavelengths or colours of visible light have a different optical path through glass which, in the extreme case of a prism, splits white light into the colours of the rainbow. This effect is called dispersion. When a lens is not correct for dispersion, images of different sizes will be generated in the plane of the recording plate. Even with modern corrected lens systems, this effect is visible when we follow Maxwell’s principal and record through red, green and blue filters. Apertures of less than f4 lead to different images sizes and the rgb images can only be registered in the middle of the image and diverge towards the edges. Glass is transparent in the visible spectrum but absorbs UV radiation in different amounts depending on the type of glass and its impurities [9]. The aperture reduces the amount of UV reaching the plate further and it is important to note that the amount of bellows draw or length would have further compounded a decrease in the intensity of the UV. We do not know what lenses Sutton used. We therefore tried to gauge the influence of the lens system on UV radiation by measuring the transmission of UV through a set of modern and one historic system.
Suggest explaining why it is a reference
We replaced ‘An aperture of f3.7 and a 143mm focal length, the Petzval lens gives a diameter for the effective aperture of 38.6 mm comparable to the effective aperture of the ROKKOR-QD 1:3.5 f=135mm lens. ‘ by ‘ An aperture of f3.7 and a 143mm focal length, the Petzval lens gives a diameter for the effective aperture of 38.6 mm comparable to the effective aperture of the ROKKOR-QD 1:3.5 f=135mm lens as a first attempt to gauge the through put of UV radiation through a lens system’
Please indicate how many and which were used
We replaced: ‘through different apertures’ by ‘through 10 different apertures with diameters ranging from 2 mm to 20 mm in 2 mm steps’
Please indicate which ones were used. Are those related with the ones historically used and can be related with Maxwell's and Sutton's experiments and results?
We replaced ‘UV transmittance through 4 different lens systems.’ By ‘UV transmittance through the lens systems ROKKOR-QD, Soligor 1:2.8 and Rodenstock Reomar (see table 1)’
For the reasons for the choice see above and the first two sentences in 2.2.
Why is the selection of lenses different from the previous experiments? why not using the same for all?
Please explain why you selected these three and how are they relevant to this work. Also, clarify if they are some how related with those historically used.
Why is the selection of lenses different from the previous experiments? why not using the same for all?
We performed the experiments in England and in Canada. The UV lamp is in England, and only the Rokkorm, Soligor, Rodenstock and Halina are in England. The Halina could not be mounted stably on the detector.
For the reasons for the choice see above and the first two sentences in 2.2.
Please indicate which ones were used
We replaced ‘UV and visible light transmittance through 4 different lens systems. The light source was the sun.’ by ‘UV and visible light transmittance through 7 different lens systems (see Table 2). The light source was the sun.’
More detail is needed to understand the experiment.
Why did you selected the lithographic plates mentioned?
How many were used per type of experience?
How were they exposed to the UV?
We replaced ‘In experiment 4, we used the sun as a light source. We measured visible and UV radiation during several days in summer, autumn, and winter. The light and UV levels varied according to season and location. To investigate the influence of UV only on image formation, we used Ipagsa ECO 88S positive lithographic plates which have a spectral sensitivity between 350 to 450 nm, with a peak sensitivity at 400 nm and a required energy of 45- 55 mJ/cm2 for image formation’ by ‘In experiment 4, we used the sun as a light source because it was Sutton’s light source. We measured visible and UV radiation during several days in summer, autumn, and winter. The light and UV levels varied according to season and location.
Wet collodion can record the visible and the UV range of sunlight. To investigate the influence of UV only on image formation, we used Ipagsa ECO 88S positive lithographic plates mounted in the Halina 6-4 camera which have a spectral sensitivity between 350 to 450 nm, with a peak sensitivity at 400 nm and a required energy of 45- 55 mJ/cm2 for image formation. Ipagsa ECO 88S is a commercially available plate. It can be easily cut to any size.’
It is the first time that a separation of the UV radiation is done. I suggest presenting UV radiation (per range of wavelenghts) before presenting the UV lamps used for the experiments and discussing their selection for this work. I also suggest indicate if the lamps are UVA, UVB or UVC range.
In Table 2 we replaced ‘Normalized transmission’ by ‘Normalized transmission by the sun’ to clarify that the light source was the sun and not a lamp.
Please support your proposal. In which reference do you base your assumption?
We replaced ‘We can also safely assume that the reflectance from the red tartan ribbon based an illumination of about 2000 mW/cm2 was in the range of 400 mW/cm2 [7]’ with ‘We can also safely assume that the reflectance from the red tartan ribbon based an illumination of about 2000 mW/cm2 was in the range of 400 mW/cm2 to 700 mW/cm2 ( In [7] Evans gives a reflectance curve for the red cloth with a UV maximum of 20% at 380 nm)
It is the first time that you introduce the relevance of diluting the red filter. Please introduce it and clarify the relevance of this topic for the work under study and for your experiments
We replaced ‘Even if Sutton had diluted the red filter to a homeopathic level our conclusions reveal that he would not have been able to capture enough UV in his own prescribed time of 8 mins or even before the collodion dried out, in and around 15 minutes.’ By ‘Even if Sutton had diluted the red filter to a homeopathic level, and he has diluted the solutions [6],i.e. not reducing the amount of UV reaching the plate any further, our conclusions reveal that he would not have been able to capture enough UV in his own prescribed time of 8 mins or even before the collodion dried out, in and around 15 minutes.’
it is the first time that this topic is introduced. it should be presented in the introduction.
same here, time for all plates should be presented in the introduction and related with the working time for wet collodion.
We mentioned in [3] that wet collodion can only be handled wet and therefore only in a certain time frame. We have added the reference.
Reviewer 2 Report
The paper “The Tartan Ribbon or further experiments of Maxwell’s Disappointment / Sutton’s Accident” is quite interesting and the topic covered is suitable for publication in Heritage, but I have some doubts about its novelty; in fact, the topic of the paper has been already published in Reference [3].
The authors must better stress the new information and data proposed in the present paper and, above all, to explain better the results because, for me, these are not clearly shown.
I have some specific comments and requests:
1) At page 3 the authors write: This being a reference to the Scientific American article of 1961 authored by Ralph Evans – in which he suggested that the reason for Suttons supposed success was the result of various pigments in the Tartan Ribbon having increased levels of UV reflectance in the red and other pigments. (image 4).
Why do you mean with UV reflectance in the red and other pigments? I don’t understand the meaning of this assessment. UV reflectance in the red? what does UV reflectance have to do with red?
2) Page 5: Lux meter, meter model ... Simply model …
3) Page 5: The distance between the fluorescent tubes and the UV detector was 40 cm … I suggest to remove this sentence, this information has already been reported above.
4) Page 7: What if instead of actually filtering differing wavelengths of colour Sutton merely created Neutral Density filters creating differences in exposure, not colour – such that that they could be separated into three distinct colour slides, and created a fake tri-colour image?
Created …. Creating …. Created.
The paper is not formatted according to the Heritage Template. The references must be formatted according to the standard of the Journal.
Author Response
Answers to referee 2
We would like to thank the reviewer for the comments.
The paper “The Tartan Ribbon or further experiments of Maxwell’s Disappointment / Sutton’s Accident” is quite interesting and the topic covered is suitable for publication in Heritage, but I have some doubts about its novelty; in fact, the topic of the paper has been already published in Reference [3].
In reference [3] we discussed how it is possible to replace colour filters by neutral density filters. Here we discuss whether enough UV reaches the wet-collodion plate to be recorded within the time frame of wet-collodion processing.
The authors must better stress the new information and data proposed in the present paper and, above all, to explain better the results because, for me, these are not clearly shown.
We added on page 4: In [3] we discussed whether it is possible to generate a colour picture based on recording through density filters, but did not discuss the influence of a camera lens system on the transmitted electromagnetic radiation. A lens system consists of glass lenses and an iris which transforms the incoming light into an image in the plane of the recording device, either plate, film or detector. This is easier said than done. The different wavelengths or colours of visible light have a different optical path through glass which, in the extreme case of a prism, splits white light into the colours of the rainbow. This effect is called dispersion. When a lens is not correct for dispersion, images of different sizes will be generated in the plane of the recording plate. Even with modern corrected lens systems, this effect is visible when we follow Maxwell’s principal and record through red, green and blue filters. Apertures of less than f4 lead to different images sizes and the rgb images can only be registered in the middle of the image and diverge towards the edges. Glass is transparent in the visible spectrum but absorbs UV radiation in different amounts depending on the type of glass and its impurities [9]. The aperture reduces the amount of UV reaching the plate further and it is important to note that the amount of bellows draw or length would have further compounded a decrease in the intensity of the UV. We do not know what lenses Sutton used. We therefore tried to gauge the influence of the lens system on UV radiation by measuring the transmission of UV through a set of modern and one historic system.
1) At page 3 the authors write: This being a reference to the Scientific American article of 1961 authored by Ralph Evans – in which he suggested that the reason for Suttons supposed success was the result of various pigments in the Tartan Ribbon having increased levels of UV reflectance in the red and other pigments. (image 4).
Why do you mean with UV reflectance in the red and other pigments? I don’t understand the meaning of this assessment. UV reflectance in the red? what does UV reflectance have to do with red?
We added on page 3: He argues that when red pigments not only reflect red light but also UV radiation and this radiation is recorded on wet-collodion, a false red image is created.
2) Page 5: Lux meter, meter model ... Simply model …
Done
3) Page 5: The distance between the fluorescent tubes and the UV detector was 40 cm … I suggest to remove this sentence, this information has already been reported above.
Done
4) Page 7: What if instead of actually filtering differing wavelengths of colour Sutton merely created Neutral Density filters creating differences in exposure, not colour – such that that they could be separated into three distinct colour slides, and created a fake tri-colour image?
Done
The paper is not formatted according to the Heritage Template. The references must be formatted according to the standard of the Journal.
We had major issues with the template and therefore opted for the non-formatted version which is allowed too.
Round 2
Reviewer 1 Report
No comments to add.
