Proscenium arch size?

User avatar
jon price
Posts: 480
Joined: Mon Jun 07, 2010 2:34 pm

Proscenium arch size?

Postby jon price » Wed Mar 21, 2018 4:56 pm

I know this may be in the same category of calculation as the length of a piece of string, but what height of aperture do people consider suitable for a proscenium arch front board, and why? Assuming a very shallow board (300mm) and an eye-level board height.

User avatar
RobM
Posts: 944
Joined: Sun Feb 15, 2009 4:39 pm

Re: Proscenium arch size?

Postby RobM » Wed Mar 21, 2018 5:10 pm

Jon, I usually have the track level at about 4' 6'' and then consider that a tall person could be 6' 6'' so giving an aperture of 2' (sorry, still in old money... ;) )
Also consider the height of the tallest building/ structure.
Rob
http://www.robmilliken.co.uk
Updated December 2016

User avatar
Tim V
Posts: 2265
Joined: Tue Jul 29, 2008 4:40 pm

Re: Proscenium arch size?

Postby Tim V » Wed Mar 21, 2018 5:41 pm

Eye level?

Whose eye level?

This is all set out in Iain Rice's books, have a read of Model Railway Layout Design, other books by Iain are available.
Tim V
Scalefour News Editor

User avatar
David B
Posts: 1115
Joined: Sun Jul 20, 2008 5:30 pm

Re: Proscenium arch size?

Postby David B » Wed Mar 21, 2018 6:05 pm

RobM wrote:I usually have the track level at about 4' 6'' and then consider that a tall person could be 6' 6'' so giving an aperture of 2' (sorry, still in old money... ;) )
Rob


Don't apologise, Rob. Even though I taught using it for years, I can't get on with this foreign system except for small measurements like a few millimetres. Weather forecast kept giving snow depth in centimetres but I just couldn't visualise it. I always buy wood in imperial and use fractions. I know what a pint looks like but not a litre. We use pounds and ounces when cooking. Is an acre bigger or smaller than a hectare?

martin goodall
Posts: 995
Joined: Fri Oct 02, 2009 6:20 pm

Re: Proscenium arch size?

Postby martin goodall » Wed Mar 21, 2018 6:19 pm

The optimum size of the proscenium arch depends on the viewing height.

Some years ago there were complaints about the " tank commander's-eye view" on some layouts, so clearly the aperture should not be too narrow.

As for the ideal viewing height, this will no doubt be debated till the cows come home. Somewhere about 48 inches is about as high as I would consider acceptable, but a little lower would be OK (say 39 inches upwards). But I appreciate that this raises issues for children and wheelchair users. I suspect that the best solution here is the provision of periscopes, so as not to prejudice the visual impact of the layout for the majority of viewers.

Lindsay G
Posts: 130
Joined: Thu Aug 07, 2008 2:16 am

Re: Proscenium arch size?

Postby Lindsay G » Wed Mar 21, 2018 7:53 pm

This question could cause a lot of debate - it has in our area group!

In my opinion, if we first consider what the proscenium arch is meant to achieve then its height and width on a particular layout can become clearer. It achieves the same effect as that in a theatre where it frames the stage set and hides everything that shouldn't be seen, like lighting, backstage, wings and so on. So ideally the proscenium arch on a layout should hide from view the lighting; operators; the mess behind the layout like tables of tools, coffee cups, etc.; the rear of the layout backing onto the layout - anything that distracts the viewer from the layout.

To what extent that can be achieved is going to be dependent on a whole range of factors such as how high the backscene is, how deep the layout is, what height the layout is off the ground, distance between barrier and layout. Then you've got to take into account the height of the audience. Since that can vary from children or adults in wheelchairs to would-be Harlem Globetrotters, there is little chance of being able to design it for everyone so perhaps the starting point is taking the average height of males/females (5' 10" and 5' 5") then deduct 4" to come down to eyeball level.

All the good work done in getting the best height bearing everything in mind can be undone by the finish of the proscenium arch. Back to the theatre again, when the lights are up the stage surrounds can be brightly coloured and covered in gold leaf but when the lights go down the stage alone is lit but around it is a very dark frame, allowing the audience to concentrate on the stage. So the surrounds on a layout shouldn't compete with the layout and distract the viewers - it shouldn't be brightly painted or multi-coloured, have the layout name in large ornate lettering, be covered with badges from previous exhibitions, and so on. Well, that's my thoughts anyway!

Lindsay

User avatar
jon price
Posts: 480
Joined: Mon Jun 07, 2010 2:34 pm

Re: Proscenium arch size?

Postby jon price » Wed Mar 21, 2018 9:52 pm

Some interesting thoughts, thanks everyone. As for my original question, it is about the size of the viewing space. Eye level is mine, as there is no thought of exhibition at the moment, though it will be eminently portable, and legs can be made any length to suit. Initially the layout will sit on a bookshelf and I will sit next to it. The idea that a too narrow slot will give the impression of viewing the layout from inside a tank is an interesting one in view of the theme. I wonder whether the viewer needs to see the top of every scenic element (trees, buildings), or if so whether the height of the trees needs choosing to match the height of the viewing slot. Of course if one viewer needs a periscope, why not everyone? There are some interesting boxes made (I think) in the seventeenth century where the perspective painted interior is viewed through an spy-hole. As for the appearance of the arch, plain black might seem reasonable, but as a certain assassin/politician knows, in fact dark (invisible?) green is a better colour to help things disappear from view, and again this might suit the theme.

User avatar
Flymo748
Posts: 2180
Joined: Sun Jul 20, 2008 6:00 pm

Re: Proscenium arch size?

Postby Flymo748 » Thu Mar 22, 2018 7:35 am

jon price wrote: As for the appearance of the arch, plain black might seem reasonable, but as a certain assassin/politician knows, in fact dark (invisible?) green is a better colour to help things disappear from view, and again this might suit the theme.


https://wiki.lspace.org/mediawiki/Assassins%27_Guild

If you didn't get the reference immediately ;-)

Be prepared to lose yourself for hours in L-Space...

Cheers
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

RichardS
Posts: 98
Joined: Mon Sep 26, 2016 7:51 am

Re: Proscenium arch size?

Postby RichardS » Thu Mar 22, 2018 7:54 am

Flymo748 wrote:
jon price wrote: As for the appearance of the arch, plain black might seem reasonable, but as a certain assassin/politician knows, in fact dark (invisible?) green is a better colour to help things disappear from view, and again this might suit the theme.


https://wiki.lspace.org/mediawiki/Assassins%27_Guild

If you didn't get the reference immediately ;-)

Be prepared to lose yourself for hours in L-Space...

Cheers
Flymo


We are supposed to be hitting our own backs with self made sticks not being diverted by such flippery. Shame on you Flymo for derailing the topic so efficiently. ;-)
Kind regards
Richard

I'm not always a railway modelling heretic

User avatar
Guy Rixon
Posts: 606
Joined: Sun Mar 27, 2011 6:40 pm

Re: Proscenium arch size?

Postby Guy Rixon » Thu Mar 22, 2018 4:06 pm

The important thing about the proscenium is that it should not draw the eye away from the scene behind. That means, for me three things.

1. The proscenium opening should be large enough that it doesn't occupy too much of the viewer's field of view. The heights are not best way to measure this. Instead, think of how far back the audience will be and work out the angle between baseboard and proscenium arch, then compare to the human field of view (which can be looked up, I don't remember the number).

2. The outer edge of the proscenium will draw the eye is it's in the viewer's sharp field of vision. Therefore, it needs to be more than minimally deep to avoid this.

3. The proscenium will be more distracting if it has high colour contrast with the layout. Black or "invisible green" won't help unless the layout has a dark back-scene. A light, neutral colour would do better. At the theatre my father managed, the pros was covered with light wood panelling at the top and exposed beige bricks in the side pillars.

User avatar
Le Corbusier
Posts: 1374
Joined: Wed Feb 11, 2015 3:39 pm

Re: Proscenium arch size?

Postby Le Corbusier » Thu Mar 22, 2018 4:34 pm

Guy Rixon wrote:3. The proscenium will be more distracting if it has high colour contrast with the layout. Black or "invisible green" won't help unless the layout has a dark back-scene. A light, neutral colour would do better. At the theatre my father managed, the pros was covered with light wood panelling at the top and exposed beige bricks in the side pillars.

Slightly confused here. I was always under the impression that contrast was what it was all about .... a brightly lit stage area and the proscenium and beyond dark and receding? So the light and action catches and holds the eye?

Have I misunderstood this?
Tim Lee

User avatar
RobM
Posts: 944
Joined: Sun Feb 15, 2009 4:39 pm

Re: Proscenium arch size?

Postby RobM » Thu Mar 22, 2018 5:15 pm

Tim, that would be in a darkened theatre where it would work but at exhibitions and probably at home best to choose a neutral colour, at an exhibition squint into the background and all will appear various shades of grey (that's inviting comments.... :o ) so I go for grey. I'm in agreement with Guy point 3.
Rob
http://www.robmilliken.co.uk
Updated December 2016

User avatar
Noel
Posts: 1143
Joined: Wed Jun 23, 2010 1:04 pm

Re: Proscenium arch size?

Postby Noel » Thu Mar 22, 2018 8:07 pm

The tank driver's visor description was largely because layouts are long, but most have only a small vertical range, so the surround tends to mimic this, whereas theatres with arches usually have a viewing area presented to the audience which is much nearer square. This may lead to the audience having to ignore some of the surroundings, but, so long as the action on stage is engaging, this doesn't seem to be a problem.

I think that too many layouts which use this approach restrict the vertical component of the opening far too much, which is why, at just over 6ft, I so often have to adopt a rather uncomfortable posture to get a proper view of such layouts. On the other hand, I understand that it's done to control the view of [and not over] the backscene, which is often quite low for operational reasons. Operation from the front, a proscenium arch and a high backscene seems to work reasonably well, but operation from the back and a concommitant low backscene seems to lead to a slot which has inadequate vertical distance. Perhaps we don't need to try to control sightlines that much? The human visual system is generally quite good at ignoring things which are not relevant to the focus of attention.
Regards
Noel

User avatar
Flymo748
Posts: 2180
Joined: Sun Jul 20, 2008 6:00 pm

Re: Proscenium arch size?

Postby Flymo748 » Fri Mar 23, 2018 6:14 am

Noel wrote:I think that too many layouts which use this approach restrict the vertical component of the opening far too much, which is why, at just over 6ft, I so often have to adopt a rather uncomfortable posture to get a proper view of such layouts. On the other hand, I understand that it's done to control the view of [and not over] the backscene, which is often quite low for operational reasons. Operation from the front, a proscenium arch and a high backscene seems to work reasonably well, but operation from the back and a concommitant low backscene seems to lead to a slot which has inadequate vertical distance. Perhaps we don't need to try to control sightlines that much? The human visual system is generally quite good at ignoring things which are not relevant to the focus of attention.


Come to Scaleforum in September to see a layout which solves this conundrum! There's a hint at one of the star attractions this year...

Not only are the Dutch the tallest nation in Europe, but they operate their layouts by standing on boxes! Flintfield is displayed at eye-level, with a tall backscene and a proscenium arch that (ignoring the discussion here about the colour of it) does an excellent job of masking the operators.

These photos are not to show the layout at its best (there are plenty of those in past Scaleforum Retrospectives - look in 2009 https://www.scalefour.org/shows/scaleforum2009/flintfield.html), but to illustrate how it is configured and operated. Note that there is both an operator at the front for shunting, and those looking over the back for other movements. Or vice versa - I can't remember which.

Flint_AH_0010.JPG


2009_0926Scaleforum0005.JPG
2009_0926Scaleforum0005.JPG (167.8 KiB) Viewed 4313 times


Flint_DD.JPG


Dutchmen on boxes, with the layout canopy in the background...

looking over the backdrop of Flintfield at the presentations.JPG


Cheers,
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

User avatar
Le Corbusier
Posts: 1374
Joined: Wed Feb 11, 2015 3:39 pm

Re: Proscenium arch size?

Postby Le Corbusier » Fri Mar 23, 2018 6:52 am

It may just be the photos ... but this demonstrates the contrast I was thinking of in my post above?
Tim Lee

User avatar
Jol Wilkinson
Posts: 788
Joined: Mon Jul 21, 2008 7:39 pm

Re: Proscenium arch size?

Postby Jol Wilkinson » Fri Mar 23, 2018 9:07 am

I have shown this photo, not because it shows anything special, but illustrates one approach to "managing" the height of the viewing window.

P1010326.JPG


The black curtain pelmets are attached to the light boxes with Velcro, so for a permanent layout could be adjusted until you get to the height that suits. They are lightweight and meant we could keep the size and weight of the light boxes down and the cloth is also less likely to damage your head if you get too close.

For exhibition layouts, it is worth remembering that viewers often lean on barriers if provided, thus lowering their line of sight.

There is no back scene because it would obstruct the operators view, standing on boxes wouldn't suit our approach to operating so a full length platform would be needed and it would restrict our interaction with viewers.

User avatar
Noel
Posts: 1143
Joined: Wed Jun 23, 2010 1:04 pm

Re: Proscenium arch size?

Postby Noel » Fri Mar 23, 2018 11:07 am

Jol Wilkinson wrote:For exhibition layouts, it is worth remembering that viewers often lean on barriers if provided, thus lowering their line of sight.


Fine if there aren't too many people watching, although not my preferred option, for the same reason I don't like having to try and see under a too low top of the "visor" - it isn't very comfortable. If there are more people it just means that those in the front can lean on the barrier and see, whilst those standing behind all too often just get a good view of the top part of the "visor"...
Regards
Noel

User avatar
jon price
Posts: 480
Joined: Mon Jun 07, 2010 2:34 pm

Re: Proscenium arch size?

Postby jon price » Fri Mar 23, 2018 11:27 am

I'm beginning to think that for preference I would avoid the arch, but it is a relatively convenient way of supporting the lighting without building gantries and other feats of engineering, which wouldn't fit on top of the furniture at home anyway. All this also has to take into consideration that the most likely home will involve a stack of two or three units, so this is a further factor in the height question.

User avatar
Noel
Posts: 1143
Joined: Wed Jun 23, 2010 1:04 pm

Re: Proscenium arch size?

Postby Noel » Fri Mar 23, 2018 11:31 am

Jol Wilkinson wrote:There is no back scene because it would obstruct the operators view, standing on boxes wouldn't suit our approach to operating so a full length platform would be needed and it would restrict our interaction with viewers.


Whether or not you agree with iain Rice's views on theatrical style layout presentation, it does have a reasonable rationale, and, together with his high level layouts operated from the front at one end, produced a view which generally achieved the intended control of viewpoints whilst permitting virtually all a full view. Children could stand on stools, and wheelchair users needed periscopes; not ideal, but with this style of presentation viewing is likely to be sub-optimal for someone, unless you have a very deep "visor".

I'm afraid that, to me, using a visor without a backscene seems to me to be rather pointless [sorry, Jol], especially when the layout is at about waist level [judging by the figures in the background]. It doesn't constrain the sight lines in the way Iain apparently intended, and the top of the "visor" potentially obstructs the vision of anyone standing behind the front row. It will help to hide the lighting rig, perhaps, but would not a slightly deeper facia mounted higher achieve the same effect without obstructing the view of the layout in the same way?
Regards
Noel

User avatar
Le Corbusier
Posts: 1374
Joined: Wed Feb 11, 2015 3:39 pm

Re: Proscenium arch size?

Postby Le Corbusier » Fri Mar 23, 2018 11:44 am

I have to admit I thought the whole purpose of a proscenium was to create a "stage' effect .... so full enclosure at the rear via the back scene was part and parcel of the approach. A window into another world as it were rather than a layout within a room.
Tim Lee

Armchair Modeller
Posts: 1131
Joined: Thu Jan 06, 2011 7:34 pm

Re: Proscenium arch size?

Postby Armchair Modeller » Fri Mar 23, 2018 11:57 am

On a more general level, if all the layouts were screened like those above, the atmosphere at an exhibition would get very repressive, gloomy and claustrophobic.

Just imagine walking along narrow gangways with what are effectively tall, dark fences either side. It would make the alleyways quite dark, I would imagine too, as it could severely restrict illumination from the overhead lighting.

User avatar
Ian Everett
Posts: 385
Joined: Tue Jul 21, 2009 9:43 pm

Re: Proscenium arch size?

Postby Ian Everett » Fri Mar 23, 2018 2:24 pm

Jon, if you come to the CRAG meeting at my ouse on Yhursday you can see what I've done with Clecklewyke and Humber Dock. I've set the track level at 6" below my eye level - 53" - and the bottom of the proscenium arch at 70". I have a very tall background - right up to my ceiling. With smaller backgrounds you might choose a lower height for the proscenium arch. This works for me but it's alwaysa compromise . It's now a home layout but I worried when I exhibited it about wheel chair users.

As others have suggested do read Iain Rice's musings on this - plenty of food for thought.

Ian

User avatar
Jol Wilkinson
Posts: 788
Joined: Mon Jul 21, 2008 7:39 pm

Re: Proscenium arch size?

Postby Jol Wilkinson » Fri Mar 23, 2018 3:05 pm

Some contradictions appearing here, especially where exhibiting layouts are concerned.

I support Iain's views that layouts should be well presented (and both own and have read his books), but we have to adapt those ideas to suit our own circumstances.

Scaleforum and ExpoEM don't provide barriers, but they don't set out to attract the casual or family visitors. Where shows do so then barriers are a necessity in my view. One genuine concern that I have is damage from small hands (it is rarely appreciated that children have a third eye for close up viewing, situated at the end of their index finger). A few parents seen to have, or wish to have, no control over the behaviour of their offspring.

If people choose to lean on barriers, that may because they want to get down to a lower viewing level or enjoy having a bit of support. If you raise the viewing height, then those of shorter stature will be disadvantaged.

Guy's suggestion that the height itself is irrelevant until you define the viewing conditions (I hope I've got that right) is spot on. The difficulty is that these conditions vary. Barriers or no barriers define the viewing distance. Viewers' eye level has an influence. And so on, all of which is rather difficult to allow for. Do organiser provide stepped platforms for visitors too stand on, or in the case of Noel and others above average height, holes to stand in?

Exhibition layout viewing height is a oft debated topic. London Road's baseboard surface is 42" above the floor, but the front retaining walls can increase the lowest viewing level to 47" away from the station section. The 42" height was set by the three original builders on the mid 80's, as an acceptable compromise between working and viewing heights. Some would say that is too low, some too high. Some hold the opinion that viewing level should be low enough for anyone in a wheel chair. For a permanent layout, you can obviously choose what suits you.

AM's rather dystopian vision is thankfully rarely achieved, although the Warley NEC show sometimes gets near, but that is largely down to the venue. Rarely do shows have more than a few properly presented layouts. Too often I see layouts that are too low for comfortable viewing and often have no dedicated lighting. No thought has been given to presentation and the research and skill that may have gone into the layout cannot be appreciated.

There is a conflict between the ultimate display layout concept, operated from the front or above and what is practical and economic for the owner. Operating from the front doesn't suit all layouts, while the extra infrastructure for operating from above might involve more cost, effort and transport than some builders would want to take on. How much would that be appreciated by the "average" show visitor, who apparently spend about ten minutes (or less) in front of a layout? You might say that S4 Society members would, although they generally seem to want to get round to the back of the layout to look at the stock in the fiddle yards. :)

Until and unless a "standard" for exhibition layout viewing height and distance is defined, there will always be variations based on the builders opinions. Did the Society's layout challenges specify those?
Last edited by Jol Wilkinson on Fri Mar 23, 2018 5:33 pm, edited 1 time in total.

User avatar
Le Corbusier
Posts: 1374
Joined: Wed Feb 11, 2015 3:39 pm

Re: Proscenium arch size?

Postby Le Corbusier » Fri Mar 23, 2018 3:46 pm

As usual Jol .... very interesting and informative.

I have to admit, I keep vacillating - even when thinking things through from the standpoint of just my own tastes and perspective.

On the one hand I really like to get down somewhere near to correct viewers height to appreciate a layout and love the 'Theatre' Cameo effect a la Trerice, I find it magical and can watch for hours (well a fair few minutes at least). Viewing from a higher level always feels a little strange as the appreciation is then more akin to flying over in a light aircraft and the whole has much more of a toy quality. ..... but then I completely about face, I really like the overview, and the ability to look down and beyond to appreciate much more of the layout - after all I can always crouch down to get the line-side perspective. I also enjoy getting a feel for the behind the scenes aspects and the sense of participation this brings - rather than just being an audience member.

If I can't even make up my own mind on this, I suspect there is no chance of any real consensus on the subject .... which I suggest is a good thing? ;)
Tim Lee

User avatar
Ian Everett
Posts: 385
Joined: Tue Jul 21, 2009 9:43 pm

Re: Proscenium arch size?

Postby Ian Everett » Fri Mar 23, 2018 4:00 pm

Jon, if you come to the CRAG meeting at my house on Thursday you can see what I've done with Clecklewyke and Humber Dock. I've set the track level at 6" below my eye level - 53" - and the bottom of the proscenium arch at 70". I have a very tall background - right up to my ceiling. With smaller backgrounds you might choose a lower height for the proscenium arch. This works for me but it's alwaysa compromise . It's now a home layout but I worried when I exhibited it about wheel chair users.

As others have suggested do read Iain Rice's musings on this - plenty of food for thought.

Ian


Return to “Baseboards and Carpentry”

Who is online

Users browsing this forum: No registered users and 1 guest