Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: PaulSchneider on April 29, 2010, 01:04:40 pm

Title: How do I make sure that my camera is completely parallel to a wall?
Post by: PaulSchneider on April 29, 2010, 01:04:40 pm
Hi guys,

I was just wondering: After having evened-out the camera so that is completely parallel to the floor - say with an ARCA cube - is there a technique with which I can make sure that the camera is completely parallel to a wall I want to photograph? Or do you guys just do trial and error?

Regards

Paul
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: JonathanBenoit on April 29, 2010, 01:12:34 pm
Quote from: PaulSchneider
Hi guys,

I was just wondering: After having evened-out the camera so that is completely parallel to the floor - say with an ARCA cube - is there a technique with which I can make sure that the camera is completely parallel to a wall I want to photograph? Or do you guys just do trial and error?

Regards

Paul


You need  http://www.zig-align.com/ (http://www.zig-align.com/) . It ensures that the object is perfectly parallel
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Joe Behar on April 29, 2010, 01:17:29 pm
Quote from: PaulSchneider
Hi guys,

I was just wondering: After having evened-out the camera so that is completely parallel to the floor - say with an ARCA cube - is there a technique with which I can make sure that the camera is completely parallel to a wall I want to photograph? Or do you guys just do trial and error?

Regards

Paul

Paul,

There are a number of ways to do this.

You can use a device called a ZigAlign

You can use a simple lazer pointer mounted on your camera and a mirror on the wall. The reflected beam should align with the source if the camera is perfectly perpendicular to the wall.

You can also do this visually by using 2 vertical objects that are in line with one another. One is close to the wall and the second some distance away. If you look through your viewfinder and both verticals are aligned, you are perpendicular to the wall.

I'm sure there are other ways, but the theory behind them all is the same...light travels in straight lines.

Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Rob C on April 29, 2010, 01:47:29 pm
Keith, I think Hasselblad produced more or less what you decribe, but I think it is no longer made...

On other smoke and mirror tricks: today I had to drive for an hour across the island in order to visit the principal police station in Palma in order to get my residency permit replaced. Instead of another credit card-like one, they have changed to a document that's in glorious A4 paper. Just right for fitting into rich Gucci wallets - but hardly into mine. So far, so cool. However, on getting to Fuzz Central I discovered there was nowhere in the district to park: solid, and I was there around 9am. After about ten minutes of cruising and waiting, I decided to head across town to a hospital I know too well and use their large pay-park. The taxi back to FC was 9 euros. The return run was ten euros. The hospital carpark was 6.60 euros. But, that's not all: going to the gestoria (legal eagle) earlier in the week to get the documents to take to FC involved me in getting a ticket for parking in a zone I had not realised was no loger free. The fine I am awaiting is 30 euros. The legal document cost 10 euros (which can't be paid in cash to anyone, but has to be paid in via a bank!) and the legal fee was twenty - that was very nice, thank you, in cash.

That means this permit cost not the basic ten, but a grand total of 85.60 euros.

What's a little mirror in the general scheme of things?

Rob C
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Rob C on April 29, 2010, 01:55:32 pm
Quote from: Joe Behar
Paul,

There are a number of ways to do this.

You can use a device called a ZigAlign

You can use a simple lazer pointer mounted on your camera and a mirror on the wall. The reflected beam should align with the source if the camera is perfectly perpendicular to the wall.

You can also do this visually by using 2 vertical objects that are in line with one another. One is close to the wall and the second some distance away. If you look through your viewfinder and both verticals are aligned, you are perpendicular to the wall.

I'm sure there are other ways, but the theory behind them all is the same...light travels in straight lines.



Joe, who says that the two vertical poles are placed so that they make a right angle? You'd need to carry a very large T-square to achieve that, otherwise they could be at any old angle but would inevitably still line up, one with the other. Also, once you have them perfectly aligned in one plane, your troubles still exist: you might well have the camera parallel to the wall, left-to-right, but how do you know you are not pointing up or down?

Rob C
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: CBarrett on April 29, 2010, 06:06:55 pm
I usually use a 6 inch level to make sure the camera is level and plumb, then just rotate until a prominent horizontal element (such as a ceiling plane) lines up with the groundglass (or the grid in C1 Pro).

-CB

I would like to have a really precise level machined, though!
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Joe Behar on April 29, 2010, 08:25:31 pm
Quote from: Rob C
Joe, who says that the two vertical poles are placed so that they make a right angle? You'd need to carry a very large T-square to achieve that, otherwise they could be at any old angle but would inevitably still line up, one with the other. Also, once you have them perfectly aligned in one plane, your troubles still exist: you might well have the camera parallel to the wall, left-to-right, but how do you know you are not pointing up or down?

Rob C
Rob,

Its easy...all it takes is a tape measure. You measure to the middle of the wall from one end and place a vertical object (like a light stand, extended),  move a few feet further away from the first vertical object and place your second obect the same distance from the end of the wall. If they line up you're perfectly perpendicular to the wall. This works with reasonable distances, but not for macro.

As far as pointing up and down, the best solution to that is a spirit level.

I've done this many times and it works wonderfully.

Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Bart_van_der_Wolf on April 29, 2010, 09:19:09 pm
Quote from: CBarrett
I usually use a 6 inch level to make sure the camera is level and plumb, then just rotate until a prominent horizontal element (such as a ceiling plane) lines up with the groundglass (or the grid in C1 Pro).

-CB

I would like to have a really precise level machined, though!

Hi CB,

The length of a (spirit) level only matters if you also have a known/intended flat surface of that length.

What really matters is to have a surface that has a known relation to the surface one is trying to align. Then one can apply a really accurate level to that surface (length) and determine its level of aberration from the norm. The only way I know of getting a perfect reference is by applying 2 measurements, one at a given orientation, and one at a 180 degrees rotated orientation. Any error will level out perfectly that way.

Now, having a level orientation, that still leaves the question whether the object is perfectly aligned, and if the sensor plane is perfectly aligned. Only a mirror will reveal the optical alignment in the viewfinder, which still leaves the sensor alignment. For that, one needs to use "Live View".

Lining up the subject plane with the sensor plane is the only usable solution (and then there is lens field curvature to account for ...).

Cheers,
Bart

P.S. I use, besides a mirror for plan-parallel orientation (if possible), a digital level that allows a good degree of accuracy and user calibration (to offset electronics drift, temperature). The DigiPas DWL-80 Pro (http://www.digipas.com/DWL-80G%20Pro%20Specs.html) level seems to fit most of my requirements (note, the Pro version allows a 0.05 degree readout/calibration). FWIW, they also sell through eBay.
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: elf on April 29, 2010, 09:46:01 pm
Quote from: PaulSchneider
Hi guys,

I was just wondering: After having evened-out the camera so that is completely parallel to the floor - say with an ARCA cube - is there a technique with which I can make sure that the camera is completely parallel to a wall I want to photograph? Or do you guys just do trial and error?

Regards

Paul

First you have to define the tolerances
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: paulmoorestudio on April 29, 2010, 10:28:34 pm
slapping the mirror on the wall always worked for me..
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: marc gerritsen on April 29, 2010, 11:12:59 pm
Quote from: paulmoorestudio
slapping the mirror on the wall always worked for me..


+1

as long as the mirror is flat against the wall
i used to shoot a lot of art work in different sizes and had indeed a piece of mirror against the wall
and lined the middle of the viewfinder up with the refection of the middle of the lens
with the different sizes it was easy to get a perfect set up each time in the minimum amount of time
if the photos were slightly rotated by a degree or so they could be lined up again much easier in photoshop

m

Title: How do I make sure that my camera is completely parallel to a wall?
Post by: K.C. on April 30, 2010, 12:17:05 am
I've had one of these for 20+ years. You place it on the wall or surface you want to be aligned to and then rotate the spirit level. Then take it over to your camera and align the camera until it's the same.

(http://merithost.net/inclination.jpg)
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Dick Roadnight on April 30, 2010, 02:25:16 am
Quote from: paulmoorestudio
slapping the mirror on the wall always worked for me..
The great thing about a simple mirror system is that you can use gravity to keep the copy on the copy stand, without tripod legs getting in the way, e.g. at a convenient angle of about 45 degrees. It would even work in orbit (where bubble levels would not work).

If you want to photograph a wall, do not assume that the wall is vertical!

Plumb lines are more accurate than bubble levels (and cheap).

The zig-align web site seems to try to make the simple seem complicated!
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: ced on April 30, 2010, 04:54:44 am
You obviously haven't visited parts of the world where neither the walls nor the ceilings are parallel...
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Dick Roadnight on April 30, 2010, 05:45:18 am
Quote from: ced
You obviously haven't visited parts of the world where neither the walls nor the ceilings are parallel...
If I found a wall that was parallel to a ceiling...

My house is over 100 years old, and the walls in the back of the house are less vertical than those at the front, and there are hundreds of buildings hundreds of years old in the area, many with ceilings at 30 or 40 degrees!
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: CBarrett on April 30, 2010, 07:12:10 am
Quote from: K.C.
I've had one of these for 20+ years. You place it on the wall or surface you want to be aligned to and then rotate the spirit level. Then take it over to your camera and align the camera until it's the same.

(http://merithost.net/inclination.jpg)

I've had that exact same one... for maybe 15 years and love it.  I've actually had assistants use it to set all the monitors at the same tilt in office interiors.  That's not crazy, right?  Definitely not.  Definitely set all the monitors to 72 deg.  All the monitors to seventy two degrees but not on Thursdays never on thursdays.

CB
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: CBarrett on April 30, 2010, 07:15:07 am
Quote from: ced
You obviously haven't visited parts of the world where neither the walls nor the ceilings are parallel...

LoL... well they do often disagree... but a horizontal edge (usually close to the edge of the shot) is going to be the most noticeable thing out of square, so that's what I go by... for interiors work.

WooHOOO  I just installed CS 5. 64 bit Baby!
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: paulmoorestudio on April 30, 2010, 08:09:21 am
Quote from: Dick Roadnight
If I found a wall that was parallel to a ceiling...

My house is over 100 years old, and the walls in the back of the house are less vertical than those at the front, and there are hundreds of buildings hundreds of years old in the area, many with ceilings at 30 or 40 degrees!

I guess if you have walls, floor and ceilings that are out of whack then all you really need is a tripod and an eyeball to get you close to level..
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: JonathanBenoit on April 30, 2010, 08:15:13 am
I'm sure he is looking for the most precise method which is employed for high end fine art reproduction. Zig-Align and even Dian-Align are really the only options I have found. Dian-Align makes it possible without touching the material which, in most cases is a requirement.

For this type of work, getting it close is not close enough.
Title: How do I make sure that my camera is completely parallel to a wall?
Post by: Harold Clark on April 30, 2010, 09:34:42 am
Quote from: Dick Roadnight
If I found a wall that was parallel to a ceiling...

My house is over 100 years old, and the walls in the back of the house are less vertical than those at the front, and there are hundreds of buildings hundreds of years old in the area, many with ceilings at 30 or 40 degrees!

It isn't only old houses that are crooked. I was doing photos of some houses in a new subdivision a few years ago with my 4x5 sinar. The levels were all adjusted dead accurate, but the grid lines were running off a bit on the ground glass. As it turned out, the houses were off, not the camera.
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Abdulrahman Aljabri on September 03, 2010, 11:37:33 pm
Is the inclination vial still being made? Neither B&H nor Google produced any results when I searched for it.
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: NigelC on September 04, 2010, 09:51:39 am
Paul,



You can use a simple lazer pointer mounted on your camera and a mirror on the wall. The reflected beam should align with the source if the camera is perfectly perpendicular to the wall.



Just so happens I have a tiny laser pointer for PP presentations - I hadn't thought to use it to align sensor plane with a brick wall - could you elaborate - I can't really see how it would prove both planes were parallel.
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Joe Behar on September 04, 2010, 10:45:03 am
Just so happens I have a tiny laser pointer for PP presentations - I hadn't thought to use it to align sensor plane with a brick wall - could you elaborate - I can't really see how it would prove both planes were parallel.

In a nutshell,

Angle of reflectance equals angle of incidence...

In simple terms, if the laser pointer is anything except exactly perpendicular to the mirror, the reflected beam will not return to the point of origin.

Keep in mind please that this method needs to be used for both the front AND rear standards if you are using a view camera. That's the only way to make sure that there are zero distortions (not counting inherent distortions in the lens)
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Bart_van_der_Wolf on September 04, 2010, 11:08:04 am
In a nutshell,

Angle of reflectance equals angle of incidence...

In simple terms, if the laser pointer is anything except exactly perpendicular to the mirror, the reflected beam will not return to the point of origin.

Keep in mind please that this method needs to be used for both the front AND rear standards if you are using a view camera. That's the only way to make sure that there are zero distortions (not counting inherent distortions in the lens)


Hi Joe,

Which raises the question; "How to mount it on the camera/standards perfectly square ?" ... Isn't that a chicken and egg situation?

Cheers,
Bart
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Joe Behar on September 04, 2010, 11:29:12 am
Hi Joe,

Which raises the question; "How to mount it on the camera/standards perfectly square ?" ... Isn't that a chicken and egg situation?

Cheers,
Bart

Bart,

In my experience, there is a certain amount of "acceptable" error, which will be compensated for by things like depth of field and depth of focus. 

I've also found that things like flash shoes on cameras and attachments for compendiums on view cameras are pretty well close enough to square to do the job.

If your needs are such that extreme accuracy is needed, then you really have no choice but to go to a ZigAlign system or something similar.

I know that there will be the inevitable responses about specs, figures, complex math and charts & graphs to "prove" me wrong, but I tend to be pragmatic about such things and go with the what gets the job done, while maintaining more than acceptable results.

If I described the systems in use at major, internationally recognized galleries and museums I've had the pleasure to deal with, you might just faint :)



Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Bart_van_der_Wolf on September 04, 2010, 01:15:00 pm
Bart,

In my experience, there is a certain amount of "acceptable" error, which will be compensated for by things like depth of field and depth of focus.

Hi Joe,

Sure, no problem, I just hoped for an ingenious solution I haven't considered before. I try to keep an open mind. One thing that helps is the use of a somewhat longer focal length. It won't help the DOF but the alignment is probably better to see/measure and the angular error smaller.

Quote
I know that there will be the inevitable responses about specs, figures, complex math and charts & graphs to "prove" me wrong, but I tend to be pragmatic about such things and go with the what gets the job done, while maintaining more than acceptable results.

If I described the systems in use at major, internationally recognized galleries and museums I've had the pleasure to deal with, you might just faint :)

Not likely but I understand what you're saying. I like simple solutions, like a plumb line for vertical alignment, a tape measure at 2 distances for horizontal alignment, and mirrors for centering. Unfortunately there are often practical obstacles that prevent doing it simple, or simple isn't accurate enough.

Cheers,
Bart
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: michaelnotar on September 05, 2010, 08:52:33 am
this is what i do for flat art copy of paintings

measure out a set distance on the wall from the center of the painting. mark it on the wall with tape. rough in the camera to be approx perpendicular to the wall. level camera/use VF grids etc... measure distance to lens from each point on wall. when they are equal you are perpendicular to the wall. 10th grade geometry...
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Rob C on September 05, 2010, 11:09:06 am
Hi guys,

I was just wondering: After having evened-out the camera so that is completely parallel to the floor - say with an ARCA cube - is there a technique with which I can make sure that the camera is completely parallel to a wall I want to photograph? Or do you guys just do trial and error?

Regards

Paul


After much thought, I concluded: glue.

Rob C


Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Joe Behar on September 05, 2010, 11:21:17 am

After much thought, I concluded: glue.

Rob C




Rob,

Can you be more specific please?

Digital or analog glue? If its digital, what is the pixel count and pitch?

Does your glue have sufficient dynamic range?

Is the signal to  noise ration high enough at high ISO?

Do you have any DxO test results for this glue?

Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Rob C on September 06, 2010, 03:23:30 pm
Rob,

Can you be more specific please?

Digital or analog glue? If its digital, what is the pixel count and pitch?
Does your glue have sufficient dynamic range?
Is the signal to  noise ration high enough at high ISO?
Do you have any DxO test results for this glue?


Glue type: that special agent stuff, you know, the kind that leaves no trace.

Dynamic range: oh yes - quite flexible, possibly due to the rubber/latex base.

Signal to noise range: no; I told you, secret agant stuff: nil decibels at any volume.

DxO test results: aren't you listening - this is all classified information - think one-minute and extrapolate from there is as far as I dare go - and only for you.

Rob C 
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Peter Barnes on September 09, 2010, 02:18:53 am
from CBarrett
Quote
All the monitors to seventy two degrees but not on Thursdays never on thursdays.

In a misguided attempt to test the wisdom of my elders and betters I did set a bank of monitors to 72 degrees on a Thursday. Was that ever a mistake - still paying the price.
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: Rob C on September 09, 2010, 03:04:54 am
I'm surprised you hadn't heard that banks have been a bad bet for a couple of years, at the very least.

Rob C
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: teddillard on September 09, 2010, 09:26:08 am
You could try sticking a tiny self adhesive mirror slap bang in the middle of the wall, or rather where you would like the middle of the wall to be. Then looking through your camera viewfinder if you can see your camera lens in the mirror you should be in alignment.

Will it work, I've no idea, but if it does then please let me know.

It will work perfectly.  And, might I add, elegantly.  :)
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: imagetone on September 09, 2010, 10:08:21 am
The mirror on the wall works for me if it can be stuck flush to the wall (ie its a flat internal wall). Even if the wall isn't perfectly vertical the camera will still be parallel to it.

Tony May
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: teddillard on September 09, 2010, 05:15:48 pm
yup, and it does in practice too...   ;D

What's that old saying?  "The difference between Theory and Practice is much smaller in theory than in practice."
Title: Re: How do I make sure that my camera is completely parallel to a wall?
Post by: teddillard on September 10, 2010, 09:52:33 am
Sorry, don't think a mirror's going to help with converging judgment.   ::)