SNH (2013) Visual Representation of Wind Farms Consultation draft

SNH (2013) Visual Representation of Wind Farms Consultation draft CONSULTATION RESPONSE FROM THE LANDSCAPE INSTITUTE AND THE LANDSCAPE INSTITUTE SCOTLAND The Landscape Institute (LI) and the Landscape Institute Scotland,the Scottish branch of the Institute (LIS) welcome the opportunity to respond to Scottish Natural Heritage s Visual Representation of Wind Farms Consultation Draft. From the outset we wish to acknowledge our appreciation of the challenge faced by Scottish Natural Heritage (SNH) in producing the draft and the hard work and consultation that has been necessary. The LI is committed to the preparation of accurate and proportionate visualisations as part of the Landscape and Visual Impact Assessment process, this continuing commitment is set out in detail in the third edition of the Guidelines for Landscape and Visual Impact Assessment (GLVIA3, 2013). We welcomed the Visual Representation of Wind Farms: Good Practice Guidance in 2006 and LI Advice Note 1/11 on photography and photomontage in landscape and visual impact assessment confirms the LI s support of its use by Landscape Architects. In preparing our considered response, the LI Technical Committee Chaired by Mark Turnbull established a working group consisting of Marc van Grieken (a Committee member), Mike Spence (an LI member) and Ian McAulay (non LI member and specialist advisor to the Technical Committee). Technical Committee members directly consulted were Bill Blackledge and Christine Tudor. Jeff Stevenson and Mary O Connor members of the LI GLVIA3 Advisory Panel were consulted as were approximately 30 practices/members known to be users of the current document and aware of, if not users of, The Highland Councils Visualisation Standards. There were approximately 20 responses either by email or by telephone. This response represents the combined views of these responses. It should be noted that a number LI members including members of the Working Group and Technical Committee attended the Workshops and site visits that have formed part of the process of preparing the Consultation Draft. We have not included reference to detailed technical considerations necessary to support the use of full frame sensors nor some of the comparison work between cameras and lenses that are being undertaken informally by several practices. Question 1: ZTVs that illustrate the screening effect of some land cover types (i.e. forestry or buildings) are now feasible. Would these be useful in addition to bare ground ZTVs? 1.1 Yes in the situations as outlined in paragraphs 39 and 40. In addition to but not instead of bare ground ZTV s, maps showing the difference between the bare ground ZTV and the ZTV with screening may be helpful in understanding the effect of screening, this is referred to as Difference Mapping. The requirement for ZTVs with screening should be agreed with the statutory consultees. 1.2 In most cases individual buildings are considered to be of too small a scale to be usefully mapped on ZTVs for wind farms (for example to 35km radius). However, generalised modelling of settlements can be useful. Experience indicates that at distances greater than 5km the amount of time involved in modelling and ground-truthing make it a costly and time-consuming exercise. Care needs to be taken to caveat any such ZTV s (datasets used, time of year ground-truthing carried out etc). 1.3 From experience we strongly advise against the use of Digital Surface Models (DSM) and recommend using digitised boundaries around settlements etc using known average heights. DSM accuracy can vary especially with woodland. At the same time, DSM applied incorrectly, can lead to the wind energy development being indicated as visible from the roofs of buildings and the top of woodland canopy which is probably correct but unrealistic for the person on the ground. 1

Question 2: This table has been adapted to reflect the use of increasingly large turbines. Do you agree with the distances proposed? 2.1 Paragraph 44 refers to act as a starting point. The table at paragraph 45 should therefore say Recommended starting ZTV distance.. to be consistent. 2.2 We are of the opinion the table in para 45 should be simpler. However while there is no clear consensus on the height ranges or the starting ZTV distance, based on experience of likely significant visual effects we suggest a range: Up to 50m 10 to 15 km 51-99m 20 to 25 km 100 + -30 t0 35 km 2.3 In particular we do not support a 45 km study area for 130m + wind turbines. On the basis that the finalised ZTV should extend far enough to include all those areas within which significant visual effects of a wind farm are likely to occur experience of sites with 130m+ turbines indicates that there were not likely significant effects beyond 20-25km. 2.4 From experience we question whether the starting distance will ever be adjusted inwards. 2.5 It may be useful to cross-reference the other SNH guidance (assessing the impact of small scale wind energy proposals on the natural heritage, Feb 2012) for turbines under 50m in height. Question 3: Presenting cumulative ZTVs in a sequence of pairs or trios can help avoid too much confusion: do you agree or do you have alternative suggestions? 3.1 Colour up to 3 wind farms can work, beyond three it is confusing. We note that beyond 3 is really impractical. 7 colours are needed for all the combinations of 3 sites; 15 distinct colours would be needed for 4 sites. Another issue is how you choose the pairs of cumulative sites to include in 3-way maps. It may be more sensible to do all maps as pairs proposal plus one cumulative. That way a user can look at the cumulative viewsheds in isolation and not have an arbitrary forced pairing. It may be more useful to map the distribution of the visibility of turbines based on the number of turbines visible as three maps number of turbines visible, number of turbines visible above the topographic horizon, number visible below the topographic horizon and thus visible against a backcloth. 3.2 The focus should be on the wind farms with which significant cumulative effects are likely to occur, not every scheme in the search area. This should be agreed with the statutory consultees. 3.3 We have some reservations about cumulative ZTV s being used for anything other than identifying viewpoints from which wirelines can be generated for the assessment of cumulative effects. However we do accept that this may depend on the visibility patterns presented cumulative ZTVs can be indicated whether the addition of a wind farm would either concentrate existing patterns of visibility of turbines, or introduce turbines into areas where they are currently not visible. 3.4 We note that all overlapping ZTVs do is show where there may be a theoretical line of sight to part of a wind farm. In some cases it could be as little as two tips one from each scheme. The ZTVs are a step on the way to identifying locations from which there may or may not be visual effects which may or may not turn out to be judged as likely to be significant. 3.5 Another approach which has proved extremely useful is to overlay the principal proposed wind farm s colour banded ZTV with hatching (up to 4 usually) with VPs also indicated. In this way it can be discerned which schemes may overlap, which viewpoints are relevant and, if accompanied by hub and blade tip ZTV s for the relevant wind farms, can assist in establishing which viewpoints are likely to be relevant to cumulative assessment. These can then be used for visualisations. 2

Question 4: The table above refers to examples of viewpoints that should be chosen. Are any aspects missing? 4.1 This table and more generally, this section on viewpoint selection, should correspond with the advice in GLVIA3 (Pages 107-110, par 6.16-6.23). In particular, the issues which influence the selection of viewpoints are described well in paragraph 6.19 and 6.20 of GLVIA3. It is essential that some viewpoints are chosen by the assessor to test judgements on the likely significance or otherwise of effects or to illustrate particular effects. This will therefore produce viewpoints that are not taken forward. We suggest that such viewpoints be included as an appendix (possibly as small images) so that the logic of choosing the final set of viewpoints is apparent. If viewpoints are required to prove the absence of a view from a particular location, these could be included as an appendix. In addition it should be recognised that some initially selected viewpoints may, following design layout iterations and mitigation measures, no longer have visibility of the proposal, and would therefore not be included within a final list of viewpoints on which the assessment is undertaken. This aspect of the process of selecting viewpoints should be clearly described. 4.2 The requirement for sequential visualisations should be clarified as being from higher sensitivity routes e.g. key tourist routes. This will enable supporting material to focus on the most important effects and to clarify that sequential visualisations are not expected to be prepared from every route where the scheme could be visible Question 5: The number of viewpoints per assessment is commonly 10-25 for wind farm proposals in Scotland. Do you think that number is reasonable? If not, how many viewpoints would you expect in an assessment? Should there be a cap? 5.1 There should not be a cap or a maximum or minimum as there will always be exceptional cases where many viewpoints are needed. The text as it stands is good because it states an expectation but does not impose a limit. Ultimately it is for the assessor to determine the number of viewpoints. 5.2 Paragraph 89 contains useful observations about increased cost to the developer and increased time commitment required by the planning authority and consultees. 5.3 The numbers of viewpoints should be reasonable and proportionate to the scale of the development informed by a ZTV, the number of people who might see it and its likely significant effects. We suggest that in some cases a maximum might be 25-30 viewpoints but for most development a number between 10 and 20-25 is reasonable. 5.4 For single turbine schemes from 4 or 5 viewpoints would be reasonable and for very large single turbine proposals perhaps 8 to 10 may be proportionate to the nature of the scheme and its likely significant effects. 5.5 The key point should be that as early in the LVIA process as possible, a definitive list of viewpoints should be agreed with the statutory consultees, based on a likely expectation of significant effects arising. The statutory consultees should be conscious of this in the selection of viewpoints, and rigorous discussion on the rationale for viewpoint selection should be undertaken. Question 6: Given the larger size of images proposed below (260mm in height) and the increased focal length, do you agree that the exact viewing distance is no longer important? 6.1 We fundamentally do not agree. The reasonable representation of what the actual view might look like depends on the properties of an image: camera lens (focal length), crop factor (if applicable), printed size and principal distance referred to in the document as viewing distance; this is the distance at which the perspective of the original scene is correctly reconstructed. When viewed at any other distance the perspective is not properly reconstructed and the image is therefore geometrically misleading. We note that the geometrical perspective that would be experienced at the viewpoint is the only aspect of the experience at the viewpoint that can be replicated (by monocular viewing). It is the one bit of objectivity that can be relied on. Comparing geometrical perspective of the printed visualisation with the actual view at the viewpoint (e.g. with an acetate) is often the only way in which some observers will believe that the representation is geometrically correct. However, we acknowledge the reality of informal binocular viewing, as recommended in the guidance, will happen and different sorts of 'not 3

geometrically correctly reconstructed' and therefore, strictly speaking, misleading impressions may occur. 6.2 It is important to recognise that viewing distances can be difficult to manage and are frequently disregarded. The viewing distance must nevertheless always be stated even if it is not applied in practice. Question 7: Do you think that the above measures will make visualisations sufficiently accessible to the public? 7.1 No, we do not think so. 2 focal lengths of images (50mm and simulated 75mm), 3 fields of view 50mm, 75mm and panorama and no clear instructions on how they should be used is without doubt confusing for a member of the public as well as consultees. 7.2 We would also note that on line viewing removes the ability to view at an appropriate size. We consider that this requires a method of scaling to be provided with every image similar to the scale on a map or drawing. Question 8: The baseline panorama and wireline can either be presented on a single A1 width sheet, or on several A3 pages do you have a preference? 8.1 A3 can be easier for practical reasons, especially for any exposed viewpoints when undertaking fieldwork for the assessment but it is accepted that this requires multiple sheets of A3. 8.2 Assuming there may be scope to provide two images on the A1 sheet (e.g. some combination of photograph, wirelines and photomontage) rather than cutting the sheet to A4 height, we accept that A1 sheets keep the images whole but are not practical for field work. 8.3 With regards to cumulative wirelines we think a standard colour palette for Operational, Consented, Application etc should be specified. We would recommend: Proposed application: Red, Operational: Black, Consented: Green, Applications: Blue and Scoping: Orange. 8.4 There are currently two approaches to Environmental Statement production: the first uses A3 pages; the second uses the A1 wide and A4 high sheets. The advantage of the A3 page printing is cost and ease of printing. However the A1 wide and A4 high has the advantage of allowing a wider extent of stitched panorama to be included in the resultant wider images, avoiding the need to hold separate A3 sheets together. This approach would require a separate set of figures to be produced to contain just the wider panoramic images, unlike the single planar images which will be on A3 sheets. Both approaches are considered suitable so long as the quality of the printing is of a high standard. Poor quality printing results in poor visual representation of the scheme and must be avoided. It is recommended that a minimum specification for printing for the submitted ES figures should be specified by SNH, covering paper type and printing spec. 8.5 We would point out that Paragraphs 130 to 132 take no account of the nature, composition and characteristics of the existing view experienced. We do not think that all baseline panoramas/wirelines need to be 180 or 360. 90 degrees or less can be sufficient for some views. There should be flexibility to allow the field of view for the baseline panorama to be determined by the landscape professional e.g. if view is a vista or a panorama. This is covered well in GLVIA3 (p 110). 8.6 Para 150 recommends mesh perspective wirelines of the DTM are not used and that grid lines are removed to form a topographic outline similar to a sketch. We consider this recommendation is too specific and should be removed. Windfarm/Windfarmer the most commonly available and used software does not produce wirelines in the suggest format. Question 9: The original guidance recommended photomontages are used only for viewpoints within 15km of a wind farm. The proposed revised guidance suggests 20km, because of the increase turbine heights. Do you agree with this approach? 9.1 From the experience of a number of practitioners the likelihood of significant effects occurring does not normally extend beyond about 15km, and excessive production of photomontages and all that they entail is not normally justified for effects that are not significant. Photomontages 4

beyond 15km should be provided where deemed necessary, rather than as a norm (e.g. for important viewpoints where significant effects may occur beyond 15km, or where specifically requested by statutory consultees on the basis of robust reasoning). We note that in addition to the distance at which significant effects occur the ability to show turbines on montages at distances of beyond 15km in lighting conditions replicating those in the viewpoint photography is often limited and involves additional enhancement of the turbines. This can get tricky when other wind farms are present in the view at similar or greater distances. 9.2 We note that using a 35mm lens the pixel resolution for 5m wide turbine column at 9 km is approx 2 pixels, compared to the 4 pixels from the 50mm lens. As a result it is clear that extracting a 75mm cropped frame from a 35mm image will give a resolution approx 50% poorer (based on pixel density) than the equivalent image taken with a 50mm focal length lens, this will be very noticeable in the 75mm extraction. At 15km a 5m wide turbine tower would be two pixels wide (but a lot higher) on a 750mm Principal Distance print (same on 20Mp FFS and 50mm lens). It would show on photograph but a montage would probably have to overstate the contrast a lot. Thus we think this is a situation where a longer lens photo and montage, as an inset figure, would be a good idea if it was agreed with the statutory consultees that it had to be shown. Question 10: the two options above (A and B) result in the same panoramic image, they differ only in the lens used to produce this. Either is acceptable for landscape and visual impact assessment. However, do you have a preference for the use of a 50mm lens (with stitching) or a 35m lens to produce the panorama required? 10.1 The preference is to use an SLR with a fixed 35mm lens because it provides a greater horizontal field of view and avoids stitching and simplifies verification. Therefore the guidance should recommend one focal length only e.g.50mm fixed and stitching or 35 mm fixed lens. The guidance should explicitly warn against using zoom lenses. 10.2 As it is written the guidance seriously confuses lens focal length with image enlargement. 10.3 It was noticeable during the field visit that the 50mm lens produced a sharper image whilst the 35mm lens image was noticeably a little blurred towards the edges. However based on field testing both images reflected the actual visual experience in the field and were representative of the actual view as can reasonably be required. Purely on a technical basis it is acknowledged that enlarging and cropping a 35mm image to produce a 75mm equivalent panorama would make good visibility even more critical to obtain a sharp enough image to use. There would therefore be fewer suitable days in the year for site work and greater potential for having to re-visit a viewpoint location to re-take the photograph. 10.4 We would therefore recommend that both a 35mm and 50mm lens should be used for site photography. The 35mm lens should be used for a single planar image. The 50mm lens should be used for both a wider cylindrical view, using overlapping frames, and also to extract the 75mm equivalent from. Question 11: Do you think that this image size (A4 in height, A1 in length) is practical to be used in the office and in the field? 11.1 A1 may be practical in the office, for public display and for use at Inquiries but as noted in 8.2 it is not practical for fieldwork. In the field it is likely that only the central part of the image would be used and the remainder rolled or folded out of the way. Question 12: Do you think that the optional extra images described above are helpful? 12.1 Transparencies (using clear acetate) can be helpful during the fieldwork and assessment so their presentation is not an additional burden, these are helpful for site visits. 5

12.2 The A3 print of the panorama will confuse matters. This introduces a third scale of image when two are already required. This has the potential for further confusion. 12.3.We acknowledge the increased usage of digital media and support this subject to resolving key issues relating to the scale of the image and viewing distance when viewed on a computer monitor and the need for making digital images available being reasonably required and in proportion to the scheme being considered. 12.4 In addition we note that storage will be required for all the hard copy and electronic data for somewhere between 5 and 7 different presentation sheets now being suggested for each viewpoint. For a 25 viewpoint ES this will mean up to 175 sheets (without even taking cumulative viewpoints into account). Currently under the 2006 guidance typically 50 sheets are produced so a 3.5 fold increase in paper and electronic data is likely to be required.. Furthermore the proposed additional image formats, other than transparencies, are not needed by the Landscape professional in order to make robust judgements on the landscape and visual effects required by the EIA regulations. Question 13: Do you think that aerial views for large offshore wind farms could be helpful? 13.1 No. These views do not represent the predominant method by which people will view an offshore windfarm (this requires a window seat on a plane with a sideways view through windows that distort the view and if behind an engine then the heat haze further distorts what is seen). With regard to GLVIA3, magnitude of impact may depend on duration of exposure. Also, a plane flying over an offshore wind farm may vary in height, route etc. 13.2 Para 187. Frequent periods of exceptional visibility occur in north and west Scotland. Met Office data suggests that conditions of very good and excellent visibility (terms defined by the Met Office) occur over periods of limited frequency, we therefore question this statement. 13.3 Para 195. Consider adding a bullet to recognise that one of the key factors in offshore wind farm viewpoint photography is achieving a contrast between the sky and the sea, so that the horizon is clear. Question 14: Are there any other factors to take in to account for offshore wind farms? Is the same focal length of 75mm appropriate for photomontage? 14.1 Use of a 75mm focal length lens is not appropriate as there is unlikely to be sufficient context as a wide panorama will normally be needed to get some shore context. If the reference is not to a 75mm focal length lens then this question is confusing. Question 15: Do you think a photomontage is required from every viewpoint (within 20km), or will wireframes alone from some locations be sufficient? 15.1 A photomontage is not required for every viewpoint within say 20km, the viewpoints for photomontage should be decided with statutory consultees as appropriate to the scheme and likely significant effects. 15.2 Wireframes from some locations may be sufficient particularly if the effects are not likely to be significant. However the use of overlay photowires should be considered where the majority of the turbines would be screened by intervening vegetation or buildings. These are also a cost effective alternative to photomontages, irrespective of whether turbines are predominantly screened or not. 15.3 Taking into consideration aspects such as frequency of use of a remote viewpoint location by the public, health and safety in undertaking fieldwork to remote / inaccessible locations and costs to the developer, suggest that such viewpoints should be wireline only unless special circumstances apply. 6

Question 16: Presenting sequential cumulative impacts as bar charts tallying with the relevant coloured sections of roads has been found useful. Do you agree or do you have alternative suggestions? 16.1 Presenting sequential cumulative impacts should be as appropriate/proportionate to the scheme/assessment and the likely significance of any effects. It is likely that bar charts would be overload for an LVIA but this would be choice of the assessor.,they may be useful as PLI material in a situation where sequential cumulative impacts along route are considered to be a determining issue. 16.2 Visual descriptions / text is usually easier to follow; plans could highlight the sections of road from which there would be theoretical cumulative views (using different colours for different wind farms). Plans and visualisations are more appropriate to LVIA than bar charts. Question 17: Do you think it is reasonable to expect members of the public to visit local libraries, Council offices or public exhibitions to view images correctly (as is current practice)? 17.1 Unless browsers are set up correctly and a method of scaling introduced, the current practice will have to be the method that the public see accurately scaled images that do not geometrically mislead, this will be even more important in the context of A1 size images being proposed. Images not set up for scaled screen viewing should have all necessary and clearly set out caveats to make that clear. Question 18: If viewed on screen, do you think it is important to provide an accurate representation of the wind farm, or is a reasonable representation sufficient? 18.1 In order not to mislead then it is important to provide a reasonably accurately scaled image as noted in 17.1 above however it is not clear how this might be achieved (See 7.2 for a possible method). It is important that it is recognised that this is not a substitute for viewing the images in the field. In any event, a reasonable representation should be sufficient in printed form never mind in screen form it is after all not going to be realistic so the aim should be for understandable and unbiased representation. 18.2 There should be a health warning on the on-screen version that the image is representative and that accurate information is only possible from viewing printed versions of the images at the correct scale. Question 19: Do you think an interactive viewer, such as the one in paragraph 227, to view images on screen is helpful? Should developers be required to produce images in this way, or is this disproportionate in terms of time and cost? 19.1 It is thought that interactive, web-based viewing will for the public become the norm and therefore creating visualisations so that they are suitable for this medium will become essential however great care is required so that the images produced are not misleading. Again it is important that it is recognised that this is not a substitute for viewing the images in the field. However, we should be careful not to get carried away with technology just because it can be done. We need to produce that which is reasonable not that which is do-able. We must be proportionate to the task in hand producing something which enables a reasonable person to gain a reasonable impression in order to make a reasonable decision. Question 20: Are there other techniques that you think offer a useful alternative for the production of ZTV s, visualisations and cumulative assessment? 20.1 One of the key elements of a wind farm is the dynamic nature of the turbine movement. Until now there has been little attempt to demonstrate this. However it is now possible to produce extremely realistic video/animation overlays which can be used to illustrate the rotational movement of the turbines. We think there is an opportunity to consider this for public exhibitions 7

but only if helpful in demonstrating the appearance of the wind farm or if the animation tailored to those locations where likely significant effects occur. 20.2 Landform modelling / flythrough are becoming cheaper to set up and more effective, this should be recognised in the guidance. Question 21: Question 21: Should the applicant be required to provide camera metadata as standard? Or should it be provided only on request from the determining authority? 21.1 We consider this should be provided only on request from the determining authority. GENERAL COMMENTS 1 CONFUSION BETWEEN LENS FOCAL LENGTH AND ENLARGEMENT We are deeply concerned about the confusion in the document between the differences that may result from using different camera lenses, e.g., 50 mm focal length lens, 35mm focal length lens etc and the use of terminology such as 75 mm equivalent which refers to enlargement to meet specified dimensions. This must be resolved as it affects the credibility of the document. We suggest the following terminology is used consistently: -75mm lens, 50 mm lens, 35mm lens, 28 mm lens: when reference is made to the actual focal length of the lens to be used for photography; -75 mm equivalent image, 50 mm equivalent image etc; when reference is made to cropping the horizontal field of view that is narrower than that captured by the original source photography using a shorter focal length lens.. 2 FULL FRAME SENSOR AND FIXED LENS 2.1 The reasons for recommending a camera with a full frame sensor and a fixed 35mm or 50mm lens must be fully explained by setting out the advantages and disadvantages when compared with say a camera with an APS-C sensor and a zoom lens and explaining why the difference matters (ie accuracy, verifiability and resolution etc). Similarly the reason behind the choice of planar projection rather than cylindrical must be comprehensively explained. In addition, with smaller fields of view it is difficult to tell the difference between planar and cylindrical projections. 2.2 The choice of a full-frame sensor severely limits the range of available cameras. In current production, the choice is Nikon (D4, D600, D800), Canon (EOS 1D X, EOS 5D mark III, EOS 6D) and Sony Alpha 99. Older models are around on the second-hand market. (Kodak used to make full-frame DSLRs but their last model went out of production in 2005.) It should be noted that not all cameras billed as having full-frame sensors actually have 36x24mm sensors. All Nikon models are 36x23.9. and the Canon EOS 5D mark I is 35.8x23.9, Sony Alpha 99 is 35.8x23.8. A 36mm wide sensor with a 50mm focal length lens theoretically gives 39.598 degrees HFOV. A 35.8mm wide sensor reduces the HFOV to 39.395 degrees. This difference is less than is likely to be seen from differences in focal length from the nominal 50mm and variations due to lens distortion. It should be noted that we have not been able to find any specifications for actual versus nominal focal lengths of lenses. A very fast 50mm lens may have slight barrel distortion, but most 50mm lenses would be expected to have close to zero distortion. 35mm lenses will almost certainly have some barrel distortion, which will make the HFOV greater than would be calculated from sensor size and focal length. There's an inexpensive piece of software called PTLens, based on Helmut Dersch's 8

Panorama Tools library. It has built-in correction parameters for a wide range of lenses. Additionally Canon produces their own software Digital Photo Professional which can undertake barrel distortion correction. 3 LENS GEOMETRY One other very important aspect is the need to understand camera/lens geometry. A 50mmm lens is normally somewhere between 49-52mm. Therefore the exact geometry of the lens must be understood to be able to calculate the field of view captured with each shot. Experience has shown that with the Canon EOS 5D Mk II and Canon EF f1,4 50mm lens the horizontal angle of view is 38.8 degrees (and not 39.6 degrees as theoretically expected). This also means that depending on what software is being using there may be the need to enter the horizontal angle of view. Unless this is done precisely there will be problems with size/scaling of the wind turbines in the view 4 PRINCIPAL DISTANCE Principal Distance and its explanation remains important if the image viewing experience is to be controlled correctly and the view is not to be geometrically misleading. As noted in 1 above the term focal length is wrongly used throughout the document when discussing print size and principle distance. This further contributes to the confusion in the guidance. 5 MINIMUM RESOLUTION FOR PRINTING The LI Advice Note 01/11 specifies a minimum resolution for printing of 300 pixels per inch(section 5.1). However it should be noted that with a Canon EOS5D Mark II, the best achievable for a 75mm crop on A3 is 243 ppi and for the planar wide angle taken with a 35mm lens is 170 ppi. We note that the guidance refers to the quality of the camera image, but this can be badly let down by a poor quality print. 6 DATA REQUIREMENTS Data requirement costs require to be considered. Profile data generally costs around 50 for the minimum area (10x10km). For some projects this will cover all or most of the viewpoints (eg single turbine). Even for larger projects needing 40 x40km coverage the cost is 400 which is not unreasonable. OS Terrain 50 (Opensource and therefore free) data sets could be checked by running different eye height ZTV s. We would support requirement for use of more detailed data for visual amenity assessment work within 5km of wind farm. Within the turbine development site the use of OS Terrain 5 data (paid for) should be considered if this is available. This gives a much better height accuracy for turbine bases. If that is not available then the use of NextMAP 5m DTM bearing in mind that experience has found to be unreliable where tree cover has been removed to produce it. It should be noted that different results are achieved with different datasets and therefore what datasets have been used should be clearly stated. 7 VERIFICATION REQUIREMENTS We are concerned about the verification requirements adopted from the THC standard. They will not work because of issues over lens focal length and sensor sizes, and probably also because of the way residual camera tilt (up to 0.2 degrees is suggested by the guidance) may be corrected for. Even if they worked the verification methods do not fulfil the requirements of an "objective, verifiable, single approach" because no attention is given to verifying that the turbines have been placed on the montage in the correct place. That is the hard part. 9

We suggest that the geometrical aspects of the verification can very easily be checked, using completely independent techniques. It can be done precisely by a land surveyor using a theodolite to measure angles at the viewpoint and compare them with the images. It can be done approximately (to roughly the same precision as the 'verification' procedures would permit given the issues over lens calibration) with a sighting compass. For many viewpoints it could be done in the office using a map, ruler, protractor and a little simple trigonometry. As for verifying that the turbines are in the right place the procedure described in paragraphs 164 to 169 can be documented. Little more is needed other than a marked up drawing with the panorama overlaid on the wireframe, any reference points marked, the source of reference information indicated and a reference graticule added to allow easy reading off of angles. Most practitioners using this technique will have the information ready to hand, perhaps documented as part of quality procedures. 8 COMENTS ON SPECIFIC PARAGRAPHS The guidance should include the requirement for taking a photo of the tripod set-up position at the viewpoint, showing its positional context. 138-141 there should be a minimum of post-processing image enhancement. 144 use of a tripod on site to view photomontages etc is not always practical and imposes another burden on people reviewing proposals etc. 174-175 - Single frame images are too restricted a view, don t show the context of the landscape and don t give a correct feel for the view. 9 ANNEX E Single frame images are too narrow a field of view and are not representative of the views from a viewpoint. All images within Annex E should be taken at the same time of year so that it is easier to compare these. The snowy photos at first glance and the single frame images in particular give the impression of a different site to the baseline panorama. 10 CONCLUSION The focus must be on why SNH are doing this. As we understand it the guidance is aimed at producing visualisations to accompany applications for consent for wind energy developments for use by all stakeholders in the process. In our view this means that the guidelines should say that this is an approach to producing visualisations which is reasonable for all parties to a standard that enables a reasonable person to make a reasonable decision. In our view the guidelines must focus on what is reasonable and proportionate rather than specify the currently achievable highest level of technical accuracy and repeatability simply because it is possible to achieve this. 11 FINAL OBSERVATION As a general observation we feel that it is very disappointing that the parties to the steering group for the new guidance, despite SNH s considerable efforts, have in the time that has elapsed not been able to come to an agreement on a joint methodology as requested by the Scottish Government. We believe this is largely due to a fundamental misunderstanding of the nature and skills required to undertake landscape and visual impact assessment. We refer to the recently published GLVIA 3 which explains that landscape impact assessment and visual impact assessments are two components of LVIA that are distinct with the landscape impact assessment assessing effects on the landscape as a resource in its own right and visual impact assessment assessing the effects on specific views and on the general visual amenity as experienced by people (paragraph 2.20-2.22). This distinction has led to the misunderstanding that landscape impact assessment is the territory of landscape architects whilst visual impact assessments can be undertaken by anybody. There should be no doubt however that both aspects of the LVIA require a professional and trained approach. It is recognised that visualisations produced in support of applications for consent may be the only medium by which some stakeholders, be they local councillors or members of the public, can gain an impression of what the proposed 10

development may look like and therefore need to have the confidence that the visualisations are reasonably accurate. This does not however extend itself to require 100% technical accuracy just because it is possible. Instead of an improvement in the Status Quo we seem to be heading towards two unsatisfactory approaches which are going to be even more difficult to work with for developers and practitioners and more confusing for the public. 11