Field Archery. Measuring or estimating distance? By Lars-Göran Swensson Translation Claes Göran Colmeus. Photo Jan Otterström

Transcription

1 1 Field Archery By Lars-Göran Swensson Translation Claes Göran Colmeus Measuring or estimating distance? Photo Jan Otterström

2 2 Field Archery By Lars-Göran Swensson Being a devoted field and forest archer all since 1960 I am very eager to preserve our popular and decisive international field round with all its unique qualities of forest archery and as high status as target archery. I have always appreciated the atmosphere and the challenge of field archery your competitors are your companions and you compete against the organizers! During the eighties I was a member of the Swedish national field archery team and won 14 national championship medals in forest and field rounds. Two national field championship gold medals and a 5th place at WG 1989 are my best merits. I was the main author of a field archery compendium published by the Swedish Archery Association in Later, Per E Bolstad used it as the basis for the FITA Field Manual, published on the FITA web. The information below is a summary of a series of articles published in the Swedish magazine Bågskytten (The Archer) with the intention to create a package of information to influence field archery in the direction I consider necessary for its future existence Contents 1. Preserve Field Archery modify the field round (Bågskytten 1-2/2007) 2 2. Target design (Bågskytten 3/2007) 5 3. Results from the poll at the Field nationals (Bågskytten 12/2007) 6 4. Distance estimating competition and the field round test (Bågskytten 1-2/2008) 7 5. Final proposal (Bågskytten 3/2008) Preserve Field Archery modify the field round You may look at field archery from two opposite viewpoints: Either field archery is a complement to target archery, with the rules designed to almost certainly make a good target archer a good field archer too. Or field archery is an independent sport with rules designed to demand special skills of the archers. This will also attract new archers who do not need to or want to focus on target shooting. Unfortunately the first point of view seems to be the most common one, but that will never give field archery its well earned wide scope and high status. The main idea with field archery must be to offer a form of competition with qualities and demands different from target archery. Compare the athletics track running (target archery) and cross country running (marked field round). The participants are the same! But orienteering attracts a totally different category and much larger numbers of participants. The fact that field archery is practised in small groups in natural surroundings is surely attractive to many people. But is it enough that the social and physical surroundings are different? If the differences in demands and skills are small, there is no sporting reason to have championships in two similar disciplines. The most important differences today (except the social environment) are shooting from unknown distances and shooting up- and downhill. Thus the field archer must be able to: 1. Estimate distances, (measuring is NOT allowed), also considering the up or down direction to the target. 2. Master his technique shooting uphill and downhill, and with uneven or slanting ground at the shooting position. We must preserve these unique qualities!

3 3 At the World Field Championships in Gothenburg I saw that archers regularly draw their bow to measure the size of the target in relation to some detail on the bow, such as the scope, the sight ring or the plunger. This will give a good indication of the distance. According to the FITA rule this procedure is not allowed, but it is described in an article on the FITA website, thus teaching how to cheat. Traditional range estimation is obviously not important any more But one of the essentials of field archery was (and is) to make use of nature itself (vegetation, level differences, slopes, lighting conditions etc.) in conjunction with shooting skills, just like orienteering where reading nature is an essential complement to running. Range estimation should be about reading nature, not being a good surveyor with technical aids. What we need is a field round which rewards the skill of range estimation even if you do not know the size of the target. Below follows a proposal for a modified field round (the first version). All important is a set of new target sizes! We need four: 70 cm, 50 cm, 30 cm and 15 cm. They must all be printed in such a way that logos, lettering etc. cannot give any clue about the target size when studied with or without binoculars from the shooting position. In other words, logos and lettering must be very small and/or be proportional to the target size. Table 1 shows my proposed new marked and unmarked distances and target sizes. For the unmarked round I suggest three targets of each size. I also give alternate solutions for the number of target faces for all sizes from 30 cm to 60 cm, to make target size estimation even more difficult. Table 1. Distances and number of faces per target for unmarked and marked course. Red peg Blue peg Number of faces per target for unmarked (U) and marked (M) course Face size Unmarkemarked Marked Un- Marked 80 cm , 55, , 45, 40 U/M New 70 cm , 50, , 40, 35 U/M 60 cm , 40, , 35, 30 U*** U/M* New 50 cm , 35, , 30, 25 U/M U* 40 cm , 25, , 20, 15 U*** U/M New 30 cm , 20, , 15, 10 U/M U** 20 cm , 15, , 10, 5 U/M New 15 cm , 10, , 5, 5 U/M *) The buttress should be somewhat larger than standard, especially if it is circular. A proper size for a rectangular buttress would be about 128 x 140 cm. **) If the buttress is circular it MUST be larger than standard. A proper size for a rectangular buttress would be about 128 x 140 cm. ***) Should not be used on a marked course. Risk for arrow collisions. To create similar visual impressions for different target sizes we also need a new buttress design. The rules should explicitly state that the buttress sizes for the unmarked round shall be adapted to the target sizes, and that the buttress size can be modified by a attaching a cardboard sheet (or by pasting the target face to cardboard), larger than the buttress itself. See fig. 5, page 11. Below, this is called background. Of course scoring zones and an adequate safety zone (from the lowest scoring zone to the edge of the buttress) must remain within the buttress. The same quality of paper should be used for all sizes, giving no clues to the target

4 4 size. The present rules allow for a background larger than the buttress, as long as the safety zone is at least 5 cm. Table 2 shows the background sizes required to give same visual impression for three alternative relations between face and background size, for each of the four variations of target setup (A, B, C and D). The starting point is the 130 cm background, suitable for the common buttress size cm. For alternative 2 we see that: a 70 cm face on a 130 x 130 cm background at 39 m or an 80 cm face on a 149 x 149 cm background at 45 m or a 60 cm face on a 111 x 111 cm background at 33 m will create exactly the same size image on the archer s retina. See fig 7, page 12. Table 2. The background size required to create the same visual impression for different face sizes. A) 1 face per buttress B) 2 faces per buttress Face size Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 80 cm cm cm cm cm C) 4 faces (2 x 2) per buttress D) 12 faces (3 x 4) per buttress Face size Alt 7 Alt 8 Alt 9 Alt 10 Alt 11 Alt cm cm cm cm cm This method gives no clue to the face size on the target, and without knowing the target size it is impossible to measure the range. A faulty target size guess, then measured with the sight ring, will yield a 6 m range error, or, if the guess is two sizes off, up to 12 m error (mixing up a 60 cm and an 80 cm face). To establish the correct face size it will be necessary to estimate the distances using the terrain with a margin of error better than around ± (6 m the maximum measuring error). Assuming a maximum error of 2 m for measuring, it will be necessary to estimate distances in the terrain with better accuracy than ± 4 m, definitely needing practice. An archer who estimates with ± 4 m error will now and then establish the wrong face size, making measuring too uncertain, which is our aim. The targets in groups A, B and C are the ones most difficult to estimate, and the ones where measurement is most necessary. In chapter 4, Range estimating contest and the field round test I present a survey of the difficulties of estimating ranges on the suggested field round, and the effect of guessing the wrong face size. 2. Target design Too many different sizes of buttresses and/or backgrounds would be impractical. Assuming a standard buttress, the following background sizes could be useful to approximate the sizes given in table 2 (first version): 90 x 90 cm (close to 98, 87, 78 and 98 cm) 110 x 110 cm (close to 114, 111, 108 and 104 cm)

5 5 150 x 150 cm, close to 149, 152, 156 and 153 cm) 180 x 180 cm (close to 173 and 195 cm) These backgrounds can be used to create several different visual impressions of target and background sizes (fig. 1 below). Number and sizes of faces vs background sizes Fig. 1 The visual impressions of different sizes of target faces and backgrounds. The following alternatives are available: With only one buttress size, 128 cm, only alternatives 3, 6, 9 and 12 in fig 1 will create a similar visual impression for all target face sizes. All these demand 180 cm backgrounds, but alternatives 9 and 12 with, respectively, 50 cm and 30 cm faces would need even larger backgrounds. Large buttresses will be beneficial because the safety zone is wide. However, 180 cm backgrounds are very difficult to transport and handle, and they are easily damaged by rain and wind as there are 25 cm of unsupported edges. This is not a good solution. With two buttress sizes, 128 cm and 108 cm, alternatives 2, 5 and 8 will create a similar visual impression for different target face sizes. And, with a lower level of ambition for the 12 faces setups, you can get away with three backgrounds, 150 cm, 130 cm and 110 cm. If these backgrounds can be folded along the centre line they are easy to handle and transport, the largest transported item will be 75 x 150 cm. The unsupported edges will not be wider than 10 cm, see fig 5, page 11. These two buttress sizes will give you very similar visual impressions for all face sizes and acceptable safety zones. This is a good solution. In the range estimating contest and the field round test presented in chapter 4 the targets were designed according to alternatives 2, 5, 8 and 11. The figures 7 11 on pages shows these alternatives on a field, placed at distances so that they all look the same size.

6 6 With three buttress sizes, 128 cm, 108 cm and 88 cm, alternatives 1, 4 and 7 will create the same visual impressions for different face sizes. Alternative 10 will not work for all sizes, the 15 cm faces should be on a smaller background. Ignoring this, the background sizes will be 130 cm, 110 cm and 90 cm. There will be almost no unsupported edges, only 1 cm. But the safety zones will be (too) small for the two smaller face sizes in all the alternatives, clearly not a very good solution. Of course you can mix alternatives to avoid small buttresses on targets with an obvious need for larger safety zones. However, using three buttress sizes seems unnecessary. 3. Results from the poll at the Field nationals At the Field nationals in Stocka 2007, I had the opportunity to check out the archer s opinions of how the field round should be, about 50% of the participants answered my poll, and to test my suggested new round. The first question about field archery experience yielded 41% very experienced (I have participated in WC/EC/WG and at least 4 Nationals). These were considered elite, the rest, 59%, enthusiasts. When these categories are not specifically mentioned, the results refer to all the participants. Roughly: 7 of 10 want the Nationals and the qualification and elimination rounds at WC/EC/WG to be shot at the same number of marked and unmarked distances, 2 of 10 want only marked, and 1 of 10 only unmarked distances. (Fig. 2) 4 of 10 want the finals at WC/EC/WG to be shot at a combination of marked and unmarked distances, 4 of 10 want only marked and 1-2 of 10 want only unmarked distances. (Fig. 2) The enthusiasts are consistently in favour of a combination of unmarked and marked distances, while the elite favours the combination in qualification and elimination rounds only, they prefer marked distances in the finals. 80 National Field Championship participant s opinions on number of unmarked and marked targets at NC and EC/WC/WG NC and elimination at EC/WC/WG Elimination at EC/WC/WG Finals at EC/WC/WG 10 0 The same number of unmarked and marked targets Only marked Only unmarked Figur 2.

7 7 National Field Championship participant s opinions on target designs and measuring rules. 33% 26% 15% No design change and accept measuring. No design change and warn for measuring More target and buttress sizes and accept measuring More target and buttress sizes and warn for measuring 26% Figur 3. Furthermore: 5 of 10 are in favour of warning archers who try to measure with the bow, and 5 of 10 accept measuring as it is difficult to enforce a ban. (Fig. 3) 6 of 10 are in favour of more target sizes in order to make measuring more difficult and reward direct estimation. (Fig. 3) It is worth remembering that the elite has become elite under today s rules. Thus it is probable that they are reluctant towards changed conditions, intended to make them lose control. And also remember that more participants in field archery means that more enthusiasts must be attracted. 4. Distance estimating competition and the field round test Here follows a presentation of the distance estimating competition and the test, also carried out at the Field nationals in Stocka The intentions were to assess: how difficult it is to estimate distances and face sizes with 8 different faces, 80, 70, 60, 50, 40, 30, 20 and 15 cm on adapted backgrounds, and how the distance estimation is affected when the face size estimation is wrong. The targets were set up immediately after the end of Saturday s shooting. The participants walked through the 12 target course in groups of 2 to 4, judging face sizes and estimating distances. The targets were set according to the suggested round for unmarked, red peg, with intervals are 35-55, 30-50, 20-35, 20-30, 15-25, 15-20, and 5-10m. The buttresses were made up from white cardboard with wooden strips on the rear side to keep them flat. They were anchored to the ground with pegs and supported by wood strips. See fig.6, page 11. The sizes used were 150 x 150, 130 x 130, 110 x 110 and 90 x 90 cm. Each buttress had only one target face, even on targets which should have 2, 4 or 12 faces. Otherwise the work of making up the new target sizes would be overwhelming. The targets were carefully made, to look exactly like the existing faces from the shooting pegs. Any text and symbols on the faces were covered with white paint. The competitors had a protocol, also with a description of the suggested new round. Using the bow for distance measuring was explicitly allowed, however very few actually did it (1 yes, 2 partly and 36 no).

8 39 BM60 8 Thus the distance estimation was mainly direct, the results were as follows: 1. Markus Ottosson (Barebow) won with a mean error of 1.3 m per target and one target size error. He won a free participation fee for the nationals. 2. Martin Ottosson (Barebow) was second with a mean error of 1.4 m per target and two target size errors. 3. Fredrik Lindblad (Compound) was third with a mean error of 1.5 m per target and two target size errors. The median error for all participants was 3.1 m per target. Other important points: Only one participant judged all 12 face sizes correctly (Christian Hedvall, Compound) and was fifth in the competition. Two participants judged 11 face sizes correctly, and six had 10 correct sizes. The median for all participants was 8 correct sizes. Fig 4 shows that: a) there is a (weak) correlation between the number of face size errors and the mean error per target at direct estimation (Pearsons coefficient of correlation = 0.55), the straight line of regression for face size errors is roughly parallel to the curve for mean errors per target. If this relationship is true, measuring with the bow would probably not improve the distance estimation as any measuring based on the wrong target size will yield a distance error which cannot be corrected because of lack of skill for direct estimation. b) there is a large variation in the number of target size errors even for the same level of mean error, i.e. there are individuals who seem to estimate distances rather independently of how they determine face sizes. Compare individual results 5 7, 7 9, 15 17, 17 19, and The conclusion is that it is possible to determine the distance without knowing or guessing the face size. Mean error in the distance estimation competition and the number of face size errors Mean error (metre) per target 8,00 7,00 6,00 5,00 4,00 3,00 2,00 1,00 0,00 19 BM60 18 CM50 17 CM19 16 CW50 15 RM19 14 BW19 13 CM19 12 CW19 11 RM60 10 RM50 9 RM19 8 RM19 7 RW19 6 CM19 5 CM19 4 BM19 3 CM19 2 BM19 1 BM19 38 unknown 37 unknown 36 BM60 35 RM19 34 unknown 33 LB 32 LB 31 BW19 30 BM40 29 RM60 28 BW19 27 BM40 26 RW19 25 CM40 24 CM19 23 CW19 22 BM60 21 RM60 20 unknown Number of face size errors Mean error per target Number of face size errors Linjär (Number of face size errors) Place Figur 4. For a better presentation of how the archers estimated individual targets, table 3 shows the results target by target.

9 9 The table should be interpreted from left to right as follows (for target 3): The face was placed at the left side of the buttress (room for one more face) The face was 50 cm and the true distance was 27 m. The estimated distance (median) for all archers was 28 m. 10% thought the face size was 40 cm, Their median distance was 24 m. 67% got the size correctly, 50 cm, their median distance was 27 m. 20% thought the face size was 60 cm, their median distance was 33.5 m. 3% (one archer) thought it was a 70 cm target, peculiar as the face was not centered. Also from table 3: The expected and wanted effect was fully reached at five targets (numbers 3, 7, 9, 11 and 12) and partly reached at four targets (numbers 1, 5, 8 and 10). The expected and wanted effect means that a minority estimated the distance too short or too long because of a target size error, and that their mean error was just enough to cause the arrow to just hit or barely miss the scoring zone. It is not desirable that many archers miss the buttress because of a target size error. That only two targets did not at all yield the expected and wanted effect (numbers 2 and 4). That the difficulty and thus the distance error was very evident at one target, number 6. A 60 cm face was estimated to be 70 cm by 63% and 80 cm by 17%, causing the latter group to be 17 m in error. But note that even with today s rules this could happen, as 60 cm and 80 cm faces are sometimes mixed up. Table 3, results from the distance estimation contest, target by target. Target num ber Target face position = ( ) Positions for multiple faces = ( ) Face size Target distance Estimated target distance (median) Number of estimated sizes (grey fields are expected range because of face placement, correct size underlined) Estimated distance for each estimated face size (median = middle value, 50% above, 50% below) 15 cm 20 cm 30 cm 40 cm 50 cm 60 cm 70 cm 80 cm 20 cm 18 % 74 % 8 % 1 13 m 12 m 10 m 13 m 14 m 30 cm 87 % 13 % 0 % 2 19 m 20 m 20 m 20 m 50 cm 10 % 67 % 20 % 3 27 m 28 m 24 m 27 m 33,5 m 15 cm 97 % 3 % 0 % 4 8 m 8 m 8 m 7 m 60 cm 0 % 13 % 74 % 5 33 m 33 m 30 m 33 m 60 cm 3 % * 17 % 6 35 m 41 m 32 m 35 m 40 cm 3 % * 48 % 43 % 3 % 7 22 m 25 m 19 m 23 m 27 m 30 m 80 cm 8 47 m 49 m 40 cm 3 % * 10 % 64 % 23 % 9 24 m 23 m 20 m 19 m 23 m 27 m 30 cm 0 % 13 % 87 % m 18 m 14 m 18,5 m 70 cm 5 % m 42 m 38 m 50 cm 0 % 5 % 56 % 38 %* m 30 m 25,5 m 29 m 34 m *) These guesses should not be possible because of the face position on the background. 3 % * 28 m 13 %* 34 m 63 % 41,5 m 3 % * 30 m 0 % 33 % 46 m 77 % 42 m 17 % 52 m 67 % 50 m 18 % 50 m

10 10 The level of difficulty, 8 target face sizes, seems reasonably well chosen, with the exception of the smallest face which did not cause any mentionable problems. Judging all face sizes correctly on a 24 target course would probably be rather uncommon, but not impossible. A good skill for direct distance estimation would be necessary for a good score. 5. Final Proposal Here follows my proposed new field round and competition form. The tested round gave expected and wanted results for all target face sizes except the smallest. Therefore, according to table 4, the smallest face, 15 cm, is discarded and replaced by a 25 cm face, to make face size determination difficult even for short ranges. The target background should probably not be white, but uniform and adapted to natures colours (fig 11). Possibly they could be all black on the unmarked round (figs 12 and 13). The shorter shooting time (3 minutes) makes no sense unless all targets are manned by a judge/timekeeper, which is impossible. The shooting time could very well be as before, only aimed at not delaying the competition. Table 4 Final proposal 2 x 24 targets marked and unmarked (3 of each face size) Face size Red peg Blue peg Number of faces per target on unmarked (U) and marked (M) course and recommended background size (buttress size) for unmarked targets. Unmarked (U) Marked (M) Unmarked (U) 80 cm , 55, , 45, cm , 50, , 40, cm , 40, , 35, cm , 35, , 30, cm , 25, , 20, cm , 20, , 15, cm , 20, , 15, cm , 15, , 10, 5 Marked (M) U and M 150 x 150 U and M 130 x 130 U 110 x 110 Grey markings signify changes from the first version. U and M 150 x 150 U and M 130 x 130 U 110 x 110 U 150 x 150 U and M 130 x 130 U and M 100 x 100 U 150 x 150 U and M 130 x 130 U and M 100 x 100 Two day competitions, including National Championships and EC/WC/WG qualification rounds are implemented according to the proposal for marked and unmarked rounds according to table 4. Championships are always shot at new courses, thus no competitor is allowed to see or walk the course in advance. For other two day competitions it is suggested that if the competition course has 24 targets and is changed from unmarked to marked on day 2, it should be newly built on day 1. If two courses are needed because of a large number of competitors, the marked course could be a permanent training course. No archers from the same country/club are allowed to start on different courses. All test and qualification competitions for EC/WC/WG should be two day events as above. Elimination rounds at EC/WC/WG should be shot at a suitable course with equal numbers of marked and unmarked targets. The final rounds would be much more interesting for the public if they too were shot with both marked and unmarked targets, however, for sporting reasons they could be marked only.

11 11 One day competitions including District Championships are implemented either as marked or unmarked. If shot at a permanent training course, it is carried out according to the proposed marked course in table 4. If the course is newly built, the competition will be shot as unmarked. The main idea is that one day competitions on new courses are unmarked in order to attract more forest and 3D-shooters to field archery and that more marked one day field competitions are arranged, very probable if they can be shot at a permanent training course, to attract target archers to field archery. In both cases this could be the way to arouse interest in two day competitions with marked and unmarked rounds. To make distance estimation even more important on the unmarked course a scoring system like in forest and 3D-archery could be implemented, thus only one arrow counts! The score for arrows 1, 2 and 3 could be multiplied by 3, 2 and 1, respectively, (easy to remember). The resultant score for each arrow is recorded but only the highest value is summed up. The first arrow may score 0, 3, 6, 9, 12, 15 or 18 (if the first arrow is a 4 or better, you could just as well stop shooting here). The second arrow may score 0, 2, 4, 6, 8, 10 or 12 (if the second arrow is a 3 or better, you could just as well stop shooting here). The third arrow may score 0, 1, 2, 3, 4, 5 or 6 (the actual score) We must use numbered arrows, I, II and III, and the archer determines the number of arrows to shoot, see table 5. On a tie, the least number of arrows breaks the tie. Table 5. Scoring example, single arrow scoring First arrow I Second arrow II Third arrow III Target score Sum Score Score x Score Score x Score Highest arrow Arrow total 3 2 score number M M Fig x 150 cm background on a 128 cm Egertec Fig 6. During the test in 2007 the backgrounds were not mounted on buttresses, only supported by a wood batten

12 12 45 m 39 m 33 m Fig 7. From the left: an 80 cm face on a 150 x 150 cm background at 45 m, a 70 cm face on a 130 x 130 cm background at 39 m and a 60 cm face on a 110 x 110 cm background at 33 m. 33 m 27 m 22 m Fig 8. From the left: a 60 cm face on a 150 x 150 cm background at 33 m (the position for the second face is indicated), a 50 cm face on a 130 x 130 cm background at 27 m and a 40 cm face on a 110 x 110 cm background at 22 m.

13 13 27 m 22 m 17 m Fig 9. From the left: a 50 cm face on a 150 x 150 cm background at 27 m (the positions for the other three faces are indicated), a 40 cm face on a 130 x 130 cm background at 22 m and a 30 cm face on a 100 x 100 cm background at 17 m. 17 m 14 m 11 m Fig 10. From the left: a 30 cm face on a 150 x 150 cm background at 17 m (the positions for the other 11 faces are indicated), a 25 cm face on a 130 x 130 cm background at 14 m and a 20 cm face on a 100 x 100 cm background at 11 m.

14 14 Fig 11. Maybe the backgrounds should not be white, but uniform and maybe adapted to the environment. From left to right the backgrounds are camo green, tar paper black and corrugated cardboard brown. Fig 12. Possibly the faces could be all black like the old Hunters face (also see fig 13). Note that without covering the buttress with the background it will be possible to determine the face size by comparing the yellow spot with the wooden batten.

15 15 Fig 13. For an all black target to be meaningful all rings and printed text and logos must be virtually invisible from the shooting position and the background and the target face must have the same black colour and the same surface structure to make the face s edges invisible, or the face must be printed on a paper large enough to cover the background (the left target). If the face s edges are visible the distance estimation will not be more difficult for the all black target than for the standard target on a white background (compare the two targets to the right). Simply printing today s faces all black and changing nothing else is not very meaningful, it will be much better to follow this proposal and print eight (four new) sizes of the standard face.

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