Topic: DIN? NOS? ORTF? XY? WTF???

[twatts (pants are so over-rated...)]

I know them, you know them, we all know them...

But I couldn't remember the exact centimeter separations...

So I googled "DIN microphone placement" and found this:

http://www.recordinglair.com/record/location/micplace.htm

Enjoy!

Terry

[Brian]

Hey sweet link Terry! +T

[twatts (pants are so over-rated...)]

Yeah, I can't wait to try RAI and Olsen techniques!

Thanks for the +T...

Terry

[Tim]

Olsen might be sweet with subcards....

[jpschust]

if only that site told me how to mic the harp i have to track next week

[Brian]

if only that site told me how to mic the harp i have to track next week

2 LD condensors for nice fat sound.... 1 by the low strings and another by the high strings. you could create a nice stereo effect if you wanted?

or you can think of it as a vertical piano if that makes more sense.

edit: also don't mike it so close that you hear the fingers plucking more than the actual sound. experiment a little with  the distance

Brian

[jpschust]

that was my plan to try, debating going tube

[Brian]

yes, a tube mic would work great as well. good luck! hope everything turns out nicely.

Brian

[jpschust]

me too, and if not, guess whats getting brought down in the mix

[Nick's Picks]

i'm surprised they didn't discuss micing a leslie on that page.
or, did I miss it?

[jpschust]

im finding more and more that every single leslie, even the same models, are slightly different to mic.  also how you mic a leslie depends greatly on playing style

[Nick's Picks]

im finding more and more that every single leslie, even the same models, are slightly different to mic.  also how you mic a leslie depends greatly on playing style

Interesting.
How so?
say, you have a player that is like Melvin Seals vs. a Jimmy Smith type of sound.
vastly different players.  Way different voicings.
how would you differ?

[plucks]

RAI- i think thats more along the line of what i may have been running once.  Sounded great!

[Jason B]

Nice link Terry. +T.

You're right Tim. I will have to try that Olson technique with the subcards.

[Sean Gallemore]

I wonder if marc ever runs ORTF

[Gordon]

so last night at deep fried I'm running hypers din 17cm.  a guy I know (a patcher great guy)  asked why I was running xy.  I said I'm not  the guy beside me is.  I said I'm running DIN.  had no idea what I'm talking about.  my drunk ass explained as best I could in my condition.  he said run ortf, you want a stero image.    again to drunk to explain.  I do need to try ortf at the peel, never have.  dfc (can't run FOB, well everythingis fob but...) is about 35 feet back in a boomy but good sounding room (sounding a lot better these days).  what do y'all think?

[Sean Gallemore]

i think you're not running DIn either

[Gordon]

i think you're not running DIn either

why is that?  17cm instead of 20?  17 with hypers right?  edit: at 90 degrees

[John R]

nice link twatts, should end up in archive.

jr

[Tenn Man]

How much does distance from the sound source play in determining which configuration to use?

What would you use close, far away , etc.?

Thanks

[F.O.Bean]

close, i sue at least ortf, or maybe 120-130* spacing w/ great results

if im more than 40 ft back from the stage, i tend to use DIN w/ great results

try everything in between also, see what ya like;-)

[keepongoin]

another good link for mic placement info:
http://www.dpamicrophones.com/eng_pub/index.html

[twatts (pants are so over-rated...)]

Archival Information
Any information about taping that may be useful to other tapers.

Terry,
If you don't, I will!
please do us the honor.

Please, go ahead and move this Moke!

Terry

[George]

Awesome info, bookmarked that sucka, thanks a million +t!

[joel]

why is that?  17cm instead of 20?  17 with hypers right?  edit: at 90 degrees

mang you gotta have a protractor handy in your pocket proctector at shows.  sheesh...what kinda taper geek are you anyway?  

[spcyrfc]

well, i suppose this is sort of an outdated thread, seeing as it is an archive now, but
the kind of taper that carries a protracter in to a show is either a novice taper or the best sort of taper - the Precision Taper, and i know those are out there.

rock on for being able to say ORTF when ORTF is what is run.

luke

btw, my DIN looks funny.  same as the faulkner from that link with the Small Diaphram mics, right?

[bhtoque]

well, i suppose this is sort of an outdated thread, seeing as it is an archive now, but
the kind of taper that carries a protracter in to a show is either a novice taper or the best sort of taper - the Precision Taper, and i know those are out there.

rock on for being able to say ORTF when ORTF is what is run.

luke

btw, my DIN looks funny.  same as the faulkner from that link with the Small Diaphram mics, right?

I guess  I can start a thread for it later, but here's to Team Precision Taper. I've got the upgrade bug though, my protractor is cracked and I've been thinking about getting a couple small bubble levels to make sure everything is even. Yes I'm a geek and should probably seek professional help.

JAson

[SonicSound]

Nice link Terry. +T.

You're right Tim. I will have to try that Olson technique with the subcards.

Did you try it out? Very interested how it measures upto NOS.  Love the subcards up close/onstage.

[alienbobz]

another good link for mic placement info:
http://www.dpamicrophones.com/eng_pub/index.html

Link is down. Here is the updated one:

http://www.dpamicrophones.com/page.php?PID=131

Another route would be to go to www.dpamicrophones.com, mircophone unviersity, then click stereo techniques.

[bhtoque]

I ended up running WTF for an opening act last week.

For those not familliar with this method,  it is omni cap on the left mic and card on the right, 90* spaced 20cm

At least I noticed and fixed it before the main act.

JAson

[F.O.Bean]

I ended up running WTF for an opening act last week.

For those not familliar with this method, it is omni cap on the left mic and card on the right, 90* spaced 20cm

At least I noticed and fixed it before the main act.

JAson

nice!

when taping phish albany in 99, we were running my buds LD cad mics and one is omni, the other is card or hyper, sounds interesting

[jdawg]

Looking for ideas on which mic config to use this Friday when Hot Buttered Rum String Band comes to Tempe. Here's a photos of them the last time they were. As you can, the ceiling is very low. Our stands are setup center/20ft back. The cieiling actually gets highers when your back more than 20ft, so we like to stay in the low area. Sounds just aweful beyond that. There are 2 stacks on each side of the stage (not in view in this pic) but it's mainly right in front of that blue cooler stage left.

I'll be using 480/ck63's ( don't have the 61's) - first time out with these.

Thanks for any advice!

[timP]

check out this config.. haven't listendbut might work just right on-stage
Source:
Akg 414's - left microphone (omni) aprox 6 ft back on stage near keyboards and Eric's amp
right microphone on stage front - horns, Will, monitors, etc. (cardiod) >
Lunatec V3 (16 bit at 48Hz) > M1 > Coaxial cable >
Patch Bay >Toslink Optical out > Nomad Jukebox > .wav

from:
http://bt.etree.org/details.php?id=10365

[jdawg]

I think I'm going to run these ORTF and see what happens.  Can someone take a look and see if these mics look like they're setup correctly.  How much difference would someone with 'good ears' notice if your off on the degrees or centimeters by any measureable amount?  The goal for this was setup is 17cm 110 degrees. I know the 17 is there, had to eye the 110.





thanks

[Brian Skalinder]

I know the 17 is there, had to eye the 110.

Well, when I overlayed my digital protractor...no, just kidding.  Looks pretty darn good to me.  Try it out and if it sounds good to your ears - stick with it!

[F.O.Bean]

nice, altho, i personally wouldnt run the 63's ortf in that small of a place, i may even run like 70*, with a smaller spacing on caps than 17cm, maybe only 3-4" instead of almost 6.5-7"

worked well when ive done it in less than ideal situations

def looks close enuf to me to 110*

[Brian Skalinder]

nice, altho, i personally wouldnt run the 63's ortf in that small of a place

Oooo...I just assumed they were cards.  If cardioid, the ORTF looks good.  If hypers, run 'em DIN!

[F.O.Bean]

nice, altho, i personally wouldnt run the 63's ortf in that small of a place

Oooo...I just assumed they were cards. If cardioid, the ORTF looks good. If hypers, run 'em DIN!

yeah, DIN may work out REAL well, the stage looks a lil bigger than the first glance i gave it

[jdawg]

Thanks for the feedback!  Just re-adjusted to DIN - I think I'll sample this tomorrow night taping a local bluegrass band (same venue) before Friday's show and see how that works. 

[F.O.Bean]

Thanks for the feedback!  Just re-adjusted to DIN - I think I'll sample this tomorrow night taping a local bluegrass band (same venue) before Friday's show and see how that works.

good luck and let us know

[jdawg]

Got AKG's ?  That's all I can say... 

[Gordon]

Got AKG's ?  That's all I can say... 

yea and they rule your face   

[newplanet7]

Anyone Ever try running this RAI?

Bump back from the dead.

[F.O.Bean]

when i first got my 481's back in 1999, I ran alot of ORTF and NOS w/ them on my old AKG T-Bar. But since getting the Vert Bar about 5-6 years ago, I started running ALOT of DIN and fell in LOVE Then I got ck63's ine arly 2005 and fell in love w/ DINa. Even now that I have teh active MBHO's I mainly(99%) of teh time, are in an ideal location, and use teh DINa bar w/ the hypers. sounds great and very consistently. if really close, i like running hypers/NOS or cards/NOS

[Nick's Picks]

DIN is pretty satisfying no matter what sort of mics you run.
hard to mess that one up.

[Tim]

if you're in an ideal location run the cards and run em wide

[Patrick]

Anyone Ever try running this RAI?

It really doesn't seem like this would sound terribly different from true ORTF, at least with audience taping of a PA system.

[boojum]

This Williams article covers all mic patterns and how to set them up according to the width of the sound field.  It is quite simple once understood.  It even offers a way to set angles with a folded piece of 8 1/2 b 11" paper, standard writing/Xerox/printer paper.  It is all physics, not much black magic or sorcery.  Using Williams' technique you are at a good starting point and will have only minimal adjustments needed.  This would be for acoustic performances.  Recording from the stacks would be a lot easier.

Link:  http://www.microphone-data.com/pdfs/Stereo%20zoom.pdf

[newplanet7]

Anyone Ever try running this RAI?

It really doesn't seem like this would sound terribly different from true ORTF, at least with audience taping of a PA system.

That's what I was thinking.
I was going to try it last saturday, stage lip but, I went with ORTF instead.
It's only a little bigger than din on the capsule spacing.

90*@ 7.9"
VS
100*@8.3"

[Nick's Picks]

anyone remember the "nutter method" ?
he used to use minimal angle and a lot of spacing.
made good pulls.

[rockthing]

Olsen! brilliant.

back in December I was attempting to run an ortf setup,
but still hadn't internalised the numbers and
accidentally set up an Olsen. 17cm@135*
I guess it wasn't so dumb afterall.

The room was pretty small and I got a lot of 'ambiance', needless to say.
Actually, the ambient crowd recording between sets is brilliant.

I also went through a phase of accidentally running what I thought was DIN with
the mics 17cm@90*... getting ORTF and DIN mixed up... no complaints from me, though,
just not sure if I could really call that DIN or not

DIN is easy to set up, but NOS is even easier, and I have enjoyed my results so far.

NOS was especially good when closer than half way into a small club.

I've used ORTF when the PA was too loud for the room
to keep the caps from pointing directly at the stacks.

I used DIN for a couple of duet performances, both amplified and acoustic,
both would be at stage lip or on stage distance.

[F.O.Bean]

For the record, DINA=17cm/90*, not DIN. DIN's spacing is actually 20cm/90* NOS=30cm/90*, and ORTF=17cm/110*(just the same as DINa spacing, but with a 20* wider angle)

Just letting you know the correct abbreviations and naming standards for spacing/angles Those are the main ones. There is also XY=90* angle, with one capsule DIRECTLY above the other, that method of one capsule over the other one directly like that is called placing your mics 'coincidently'. DINa/DIN/NOS/ORTF/etc are considered 'near'coincident' patterns FWIW

Happy taping brotha!

Bean

[DSatz]

Bean, no particular angle or directional pattern is implied by the term X/Y--it only refers to coincident placement of two microphones, just as A/B refers to a pair of microphones that are spaced some distance apart. It's not at all clear how far apart equals "some distance," though I'm sure that most reasonable people wouldn't call an ORTF setup or sphere stereo or a Jecklin plate "A/B."

What I'd like to know is how the name "DIN" ever became attached to a stereo miking method, let alone two of them. Someone ought to fess up, I think. The DIN issued thousands of standards for industrial production in Germany--every piece of hardware on the market conformed to one or more DIN standards, or else no industrial customers would ever buy it. But the DIN standards didn't tell you how to hold a hammer for the best effect, or the most intelligent way to change a light bulb. I have copies of several DIN standard documents for studio microphones. There's a lot in there about impedances and voltages and connector types, but nothing at all about how to use them; that's not what was being standardized.

I suspect that "DIN" is someone's made-up name, either because they liked the technique and wanted to make it sound more official and important, or because they wanted to think of themselves as being important because they were the person who first gave that name to that miking technique.

But I'm very willing to be proven wrong, right here in quasi-public, if someone would just tell me the number of the particular DIN standard which specified these stereo miking methods.

--best regards

[darby]

DSatz,
here is an article that was posted here by someone else... I don't remember who
that describes different stereo configurations

I'm not saying that it is the absolute standard by any means
but it is one that most people on this site seem to follow

http://www.recordinglair.com/record/location/micplace.htm

[datbrad]

The first time I saw what is now called DIN and DINa, it was in the '80s at a Dead show. I asked the taper what that pattern was, and he called it a "near coincident 90 degree XY". For that reason, I used the term "XY" on my DAT source notes when I was doing what is now called DINa, from about 1992 until 2002. 

[taperwheeler]

According to DPA...

"It is possible to combine the principles of AB and
XY in setups normally referred to as “near coincident”.
Some successful configurations are named
after the institutions that used them first, like
ORTF (Office de la Radio et de la Télévision Française),
NOS (Nederlandse Omroep Stichting), DIN
(Deutsche Industrie Norm), etc."

[deadheadcorey]

I perfer xy and din. you have to expirement. your location depends too.

.02

[Gutbucket]

DSatz,
here is an article that was posted here by someone else... I don't remember whothat describes different stereo configurations

I'm not saying that it is the absolute standard by any means
but it is one that most people on this site seem to follow

http://www.recordinglair.com/record/location/micplace.htm

Yeah, but watch your sources.. that page also has incomplete, misleading and blatantly incorrect info:
(Quoted material in italics with my comments beneath)

XY

    Two cardioid microphones are placed at 90 degrees and the capsules are positioned as close as possible.

My comment- Incomplete & misleading. X/Y denotes two mics coincidentally placed of any pattern and any angle. For close instrument recording cards at 90deg may be a good choice, but I'd suggest much wider for our purposes when using cards, slightly less angle with hypercards and 90deg only with fig8's for Blumlein - a special case of X/Y.


MS Technique

    This technique uses two microphones placed close to each other. One microphone has a cardioid pick up pattern and the other with a figure 8 pick up pattern...

My comment- Incomplete. M/S can use any pattern for the mid mic.  Cardioid is a popular choice, but so is hypercardioid.  Omni might be appropriate on stage and a fig8 mid decoded with equal mid and side proportions = Blumlein)


  Spaced Omnis

    This technique uses two (or three for large ensembles) omni-directional microphones evenly placed in front of an ensemble. This technique can easily produce phasing problems. A 3:1 rule should be utilized. The 3 to 1 rule states that for every 1 unit of distance from the sound to the microphone should be 3 units of distance between microphones. (Example: microphones are 5 feet in front of the ensemble - the distance between the two microphones cannot be less than 15 feet - 7.5 feet each from the center line.) The microphones in spaced omni should typically be 2 to 10 feet from the center line.


My comment- Blatantly incorrect (and one of my pet peeves). The 3 to 1 rule does not apply in this case at all.  It was designed for addressing comb filtering problems (referred to as 'phasing' above) of multiple mics that will be mixed together (summed) to a single channel.  It works very well for that application. To a lesser extent it also applies to multiple mics on separate sources pan potted across a stereo bus, another form of summing the various mic feeds.  Imagine multiple on-stage FOH mics for each performer and instrument.  It does not apply to spaced stereo mic'ing where the two mic feeds are not meant to be mixed together but feed to two separate speakers.  It is in fact blatantly absurd when applied to that case. Think about it- if you are 10' back from the stage the 3 to 1 rule says you should space your mics no less than 30' apart! If you are 30' back in the section, make that 90' apart! Obviously that is extreme. But worse, it's also physically impossible. If each mic is 1 unit of distance from a single source, they can only be 2 units of distance apart from each other at most.  Thats only if the mics and source are all arranged on a single line with the source in the center.  Simple geometry.

And guess what? if you sum an A-B stereo recording you might get comb filtering! That's no surprise, but that's what the 3 to 1 rule was designed to eliminate.  In effect it intentionally creates a 'hole in the middle' as it aims to decorrelate the sources as much as is needed to eliminate the comb filtering threat, and with it any the very means by which A-B stereo works.  The 3 to 1 rule simply does not apply to stereo mic'ing, yet this mis-information is repeated all over the web in multiple places.  Don't believe it.

/rant off

[Simp-Dawg]

anyone remember the "nutter method" ?
he used to use minimal angle and a lot of spacing.
made good pulls.

i've applied that method several times with very good results.
run hypers about the same spacing as DIN (30cm) but angle them inwards so they point just at the outside of the stacks, instead of at 90 deg you'd be closer to parallel

[MIQ]

Also interesting is the "Two to One Ratio" - to get the same signal level, and direct to reverberant sound ratio, a cardioid mic can be placed twice as far away as an omni mic.  This is a generalization since the actual Distance Factor is 1.7 for a cardioid.  Hypercard is 2 though.

If you haven't checked out "The New Stereo Soundbook" by Streicher and Everest, you should.  A lot of good stuff in there IMHO.  There is a great chart on page 7.11 with different mic patterns, their polar equations, pick up arcs, random energy efficiencies, relative outputs at 90 and 180 deg, and distance factors.  Theoretical, sure, but useful for undertanding mic differences.

DSatz wrote this a while back and I respect his perspective - "there are a few things that if people doing recording would take the time to learn, it would save them from all kinds of frustration and bullshit. One of those things is Ohm's Law and its basic practical applications. Another is the difference in behavior between pressure and pressure gradient transducers (microphones), and directly related to that, the third thing is how to read the polar diagrams for microphones."  

I'm just starting to learn.  This place (Taperssection Forum) has been great as a beginner.

-MIQ

[DSatz]

gutbucket, I agree with you completely on all points in your message. Thanks for posting.

--best regards

[F.O.Bean]

anyone remember the "nutter method" ?
he used to use minimal angle and a lot of spacing.
made good pulls.

i've applied that method several times with very good results.
run hypers about the same spacing as DIN (30cm) but angle them inwards so they point just at the outside of the stacks, instead of at 90 deg you'd be closer to parallel

ahem Simpy, DIN=20cm/90*, not 30cm/90*

[Simp-Dawg]

anyone remember the "nutter method" ?
he used to use minimal angle and a lot of spacing.
made good pulls.

i've applied that method several times with very good results.
run hypers about the same spacing as DIN (30cm) but angle them inwards so they point just at the outside of the stacks, instead of at 90 deg you'd be closer to parallel

ahem Simpy, DIN=20cm/90*, not 30cm/90*

d'oh, you're right, i suck.   i must've had NOS on the brain...by the way bean if you want to hear the wide cards NOS at red rocks, go download my panic show.  i know you're not so into them, but the tape is killer and if you don't groove on jimmy herring then there's just no hope for you.

[rockthing]

  Spaced Omnis

    This technique uses two (or three for large ensembles) omni-directional microphones evenly placed in front of an ensemble. This technique can easily produce phasing problems. A 3:1 rule should be utilized. 





<snip>

My comment- Blatantly incorrect (and one of my pet peeves). The 3 to 1 rule does not apply in this case at

<snip>

/rant off

Grea+ ranT. I thought I was just crazy when I read about the 3 to 1 rule.

and referring back to my comment a few posts ago,

It's funny how sometimes you make a mistake,
and it's not a mistake. 

[sunjan]

According to DPA...

"Some successful configurations are named
after the institutions that used them first, like
ORTF (Office de la Radio et de la Télévision Française),
NOS (Nederlandse Omroep Stichting), DIN
(Deutsche Industrie Norm), etc."

Like Dsatz implied, the DIN part is incorrect, both by name and conclusion. See:
http://en.wikipedia.org/wiki/Deutsches_Institut_f%C3%BCr_Normung

DIN are "just" in charge of the norms, as opposed to RAI, ORTF etc which are broadcasting organisations.

BTW, I found another good technical overview, outlining NOS, EBS, RAI, ORTF, DIN. Check it out:
http://www.sengpielaudio.com/VergleichAequivalenzMikrofonSyst.pdf

The text is in German, but the table and diagram can be understood universally. 

[sanaka]

Disclaimer: I skipped over most of this thread and am just going to blurt out what I want to say 

Drawing on the profoundly deep well of my my recording experience (insert humongous sarcastic guffaw here), I have derived a new and unique stereo micing technique. It dawned on me after long and careful ponderance of the various stereo techniques for two cardioid mics:  ORTF NOS RAI DIN OLSON XY.

I have dubbed it ONLYORSONFARTSDIOXIN

The setup is to place the mic capsules from 0 to 30 cm apart, at an angle of 90 to 135 degrees.

I hope you all find it very flexible and able to suit your needs. 

Peace,
Sanaka

[headroom]

I use quite often LTE for Film Video Documetary. Time Level Equivalence is a compromise between ORTF and NOS 

Level Time Equal Spacing 22cm 90* with cards,  96* Field of recording like ORTF

Technique described here on page 25:

http://www.marcousticaudio.de/Stuff/Diplomarbeit.pdf

I tried to translate from german with my " Swiss English "
First wavereflextions are captured with very precise information about the soundspace without overstreching  or losing the Pinpoint Information.

[headroom]

See link
 
http://www.mpkortschak.com/html/hauptmikrofon_engl.html

Inspires from the LTE techonlogy I recognised an " invisible identity line" in the area of the equivalent Stereo microphone techniques, to which t (time) and l (level) keep the scales. LTE based on ORTF proportions. Because of the combination of the recording area and the capsel dependent treble focus, the stereophonic main axis sounds much muffled in contrast of the edge areas. Nevertheless, there is on my " invisible identity line " a point, where these tonal unbeauties are perfectly balanced. "Well balanced XY" works with the same prinziple but disclaims the time difference component.

[mtee66]

I too have skipped the better part of this thread, but thought I'd throw out an observation for your comments.

The above stereo configurations are based on "first-order cardioid" mics space and angled accordingly.  When these configurations are used with sub and hyper cards (as many tapers note in their recording specs) has the stereo effect been compromised?  What are the trade offs or benefits? 

[Gutbucket]

Yes, the pickup pattern of the mics, the spacing and the angle between them are all interrelated.

Michael Williams' Stereo Zoom paper is helpful in explaining that relationship.

[datbrad]

Also, with SD cards, they are accurate off axis slightly more than 90 degrees, and this is one of the reasons the various coincident and near coincident patterns sound good. Subs are even more accurate off axis, and I would think this makes them better suited for ORTF than any 90 degree pattern.

Likewise, I have found that hypers at 90 degrees can sometimes not sound right, due to hypers being less accurate off axis than cards, and can sometimes have a "hole in the middle" effect in the soundstage when played back. For this reason, when in a boomy room or farther back than I would be if I could choose and hypers then are called for, I usually run them at 80 degrees, spaced about head width apart.

My thinking there is that if you are in a good enough sounding space to run at 90 degrees, you don't need hypers in the first place. YMMV......

[Javier Cinakowski]

Where did DINa come from ?   Looking at the SRA diagrams, I don't think I would use this configuration with hypers (maybe cards)...   DINa gives a +/-35 SRA, which is typical for most of the venues I record in, but 120° puts you a good bit into the reverberation limit of the theory.  Using hypers in a recording situation with a SRA of +/-35 I would choose 32cm x 80°   ...  Not only would this config give you a more stable image, it would also limit more chatter and reflections from the sides.... my $0.02

I just ordered a ⅝-27 die and stock to make my own rods, so I can have a selection of mount sizes.  I'll slide the rods in a shock/isolation mount and attach my rode swivel mounts.  This would be similar to the kwon bar setup but much cheaper and I can make any size I would ever need....

I am going to make bars for every SRA angle from +/-30° -> +/-60° chosing the most ideal point on the graph. 

Here are the options I will have...
notes:
- the rode swivel mounts give 17cm without a extention bar....
- I can't make a bar larger than 22cm becasue it wont fit in my bag, so I am limited to 37cm distance....
- The threads are 1cm, so 2cm per bar of threads...
- To limit the amount of bars I need to carry, slight compromise is made on the hyper graph...

Cards:
SRA+/-30° = 37cm X 110° =  22cm bar
SRA+/-40° = 32cm X  85°  =  17cm bar
SRA+/-50° = 23cm x  80°  =   8cm bar
SRA+/-60° = 17cm x  80°  =   No Bar

Hypers:
SRA+/-30° = 37cm X  90° =   22cm bar
SRA+/-40° = 32cm X  60°  =  17cm bar
SRA+/-50° = 23cm x  60°  =   8cm bar
SRA+/-60° = 17cm x  50°  =   No Bar


So, all I need to cover a 60° -> 120° SRA without reaching the angular distortion or reverberation limits is 3 extention bars!

    

[Javier Cinakowski]

BTW, you don't need a sextant to measure the SRA.  Some kind soul here told me of an old sailing trick.  Hold your closed fist with arm extended completely out, your fist is 10°.....

[Gutbucket]

Love the 3-bar system, great idea.

BTW, you don't need a sextant to measure the SRA.  Some kind soul here told me of an old sailing trick.  Hold your closed fist with arm extended completely out, your fist is 10°.....

 

[Javier Cinakowski]

T+ Mr. Gutbucket!