Setting camera parallel to subject

Started Nov 29, 2020 | Discussions
Tom Ferguson Senior Member • Posts: 2,320
Setting camera parallel to subject

I have a couple repeat customers where I shoot big flat products and need to keep them perfectly "square" (no keystoning). Think art copy work, except BIG. Far too big for my copy stand. I can get close to parallel... but I always have to tweak it in Photoshop transform.

I've been experimenting with two mirrors, one attached to the camera lens (plastic mirror attached to filter ring with a one inch "aperture" drilled out to the center) and the second mirror dangled at the center of the product. It is an improvement, but still not "perfect".

Is there a commercial or better  DIY solution out there?

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ashleymorrison
ashleymorrison Senior Member • Posts: 1,467
Re: Setting camera parallel to subject

An example of how I am able to tell you something without using any words - which is basically what photography is all about.

Michael Fryd
Michael Fryd Forum Pro • Posts: 14,562
Re: Setting camera parallel to subject
3

Tom Ferguson wrote:

I have a couple repeat customers where I shoot big flat products and need to keep them perfectly "square" (no keystoning). Think art copy work, except BIG. Far too big for my copy stand. I can get close to parallel... but I always have to tweak it in Photoshop transform.

I've been experimenting with two mirrors, one attached to the camera lens (plastic mirror attached to filter ring with a one inch "aperture" drilled out to the center) and the second mirror dangled at the center of the product. It is an improvement, but still not "perfect".

Is there a commercial or better DIY solution out there?

You only need a small mirror on center of the flat product. When the mirror is centered in the viewfinder, and you see the lens in the center of the mirror, then you are perpendicular to the mirror.

I shoot a lot of flat artwork.

What I normally do is to make sure the artwork is flat against the wall. My floor boards run perpendicular to the wall. I notice which floor board aligns with the center of the artwork.

I use a laser level on a lightstand to project a plus sign onto the center of the artwork The lightstand is centered over the "center" floorboard.

I then put my camera between the laser level and the artwork I adjust the camera height and position so that the laser level's "plus" sign is on the back of the camera, just behind the center of the lens.

If I do this correctly, the camera is centered on the artwork, and perpendicular to it.  I use a "macro" prime lens, as these typically have very little barrel or pincushion distortion.  Macro prime  lenses generally are very sharp, and have flat field of focus.

The trick is to make sure the wall is level, the artwork is flat against the wall, and that you have a straight line on the floor coming out from the wall that is centered under the artwork.

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jlafferty Senior Member • Posts: 1,464
Re: Setting camera parallel to subject
1

Was just about to suggest a laser level.

It might be even simpler/more expedient, since you’re always working relative to the artwork and not the surface it’s on… to tether into CaptureOne, and run a grid overlay and guides along the edges of the art.

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Doug Haag Senior Member • Posts: 2,560
Re: Setting camera parallel to subject
1

Michael Fryd wrote:

You only need a small mirror on center of the flat product. When the mirror is centered in the viewfinder, and you see the lens in the center of the mirror, then you are perpendicular to the mirror.

I think small mirrors are a great tool,  I use one in portraiture work when using a single light and a reflector.  I hang the mirror against the surface of the reflector board.  When in subject position, if you can look into the mirror and see the studio strobe, the reflector is angled correctly.  Angle of incidence equals angle of reflection.

D Saul
D Saul Regular Member • Posts: 387
Re: Setting camera parallel to subject

Michael Fryd wrote:

I then put my camera between the laser level and the artwork I adjust the camera height and position so that the laser level's "plus" sign is on the back of the camera, just behind the center of the lens.

If I do this correctly, the camera is centered on the artwork, and perpendicular to it.

Interesting trick, but how does this method confirm the camera is parallel to the artwork? The projected crosshairs from the level would seem to only confirm the camera is in the middle of the level's projection but not necessarily parallel to the wall.

Michael Fryd
Michael Fryd Forum Pro • Posts: 14,562
Re: Setting camera parallel to subject

D Saul wrote:

Michael Fryd wrote:

I then put my camera between the laser level and the artwork I adjust the camera height and position so that the laser level's "plus" sign is on the back of the camera, just behind the center of the lens.

If I do this correctly, the camera is centered on the artwork, and perpendicular to it.

Interesting trick, but how does this method confirm the camera is parallel to the artwork? The projected crosshairs from the level would seem to only confirm the camera is in the middle of the level's projection but not necessarily parallel to the wall.

The key is to have a perpendicular line coming from the wall. In my case, the floor boards are perpendicular, and I use that as my reference.

Actually, you only need to mark two spots on the floor. The Centerline reference spot under the artwork, and a the Laser Level location, which must be on a line perpendicular to the Center Line Reference Spot.

In my studio, I have floorboards perpendicular to the wall. I use them as my reference.

When I hang the artwork, I am careful to center it left to right over the centerline.

I then adjust the height of the laser level so that it is centered up/down on the artwork.

I then position the camera so that the red plus from the laser level is centered behind the lens.

If you follow this steps, the camera will be aligned along the center projection of the laser level.

If the centerline on the floor is 90° from the wall, then you know you are parallel left to right.

We know that the laser level projects a level line, so we know the camera is not pointed up or down. Assuming the wall is actually vertical, we now know the centerline of the laser is perpendicular to the wall. As we are shooting along that line, we know the camera sensor must be parallel to the wall.

By the way, once you get everything parallel, you need to make sure your lighting is good, and your colors correct.

I have a colorchecker chart just next to the artwork. This gives me a good reference so I can get the colors right. I crop the colorchecker out for the final image. If artwork has a difference aspect ratio from your camera, there is usually somewhere to place the colorchecker.

For lighting, I use one studio strobe on each side of the artwork. The height of the strobe should match the horizontal laser line. The strobes should be about 45° out. I use 7" reflectors, and polarizing gels on the strobes. I use a polarizing filter on the lens. Rotating the polarizing filter on the lens allows me to control the amount of glare.  Minimizing glare generally results in more accurate colors, higher contrast, and an overall increase in image quality.

 Michael Fryd's gear list:Michael Fryd's gear list
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D Saul
D Saul Regular Member • Posts: 387
Re: Setting camera parallel to subject

Michael Fryd wrote:

D Saul wrote:

Michael Fryd wrote:

I then put my camera between the laser level and the artwork I adjust the camera height and position so that the laser level's "plus" sign is on the back of the camera, just behind the center of the lens.

If I do this correctly, the camera is centered on the artwork, and perpendicular to it.

Interesting trick, but how does this method confirm the camera is parallel to the artwork? The projected crosshairs from the level would seem to only confirm the camera is in the middle of the level's projection but not necessarily parallel to the wall.

The key is to have a perpendicular line coming from the wall. In my case, the floor boards are perpendicular, and I use that as my reference.

Actually, you only need to mark two spots on the floor. The Centerline reference spot under the artwork, and a the Laser Level location, which must be on a line perpendicular to the Center Line Reference Spot.

In my studio, I have floorboards perpendicular to the wall. I use them as my reference.

When I hang the artwork, I am careful to center it left to right over the centerline.

I then adjust the height of the laser level so that it is centered up/down on the artwork.

I then position the camera so that the red plus from the laser level is centered behind the lens.

If you follow this steps, the camera will be aligned along the center projection of the laser level.

If the centerline on the floor is 90° from the wall, then you know you are parallel left to right.

We know that the laser level projects a level line, so we know the camera is not pointed up or down. Assuming the wall is actually vertical, we now know the centerline of the laser is perpendicular to the wall. As we are shooting along that line, we know the camera sensor must be parallel to the wall.

By the way, once you get everything parallel, you need to make sure your lighting is good, and your colors correct.

I have a colorchecker chart just next to the artwork. This gives me a good reference so I can get the colors right. I crop the colorchecker out for the final image. If artwork has a difference aspect ratio from your camera, there is usually somewhere to place the colorchecker.

For lighting, I use one studio strobe on each side of the artwork. The height of the strobe should match the horizontal laser line. The strobes should be about 45° out. I use 7" reflectors, and polarizing gels on the strobes. I use a polarizing filter on the lens. Rotating the polarizing filter on the lens allows me to control the amount of glare. Minimizing glare generally results in more accurate colors, higher contrast, and an overall increase in image quality.

Maybe it's just me, but this does not seem guaranteed to produce a yaw-free camera relative to the wall.

Michael Fryd
Michael Fryd Forum Pro • Posts: 14,562
Re: Setting camera parallel to subject

D Saul wrote:

Michael Fryd wrote:

D Saul wrote:

Michael Fryd wrote:

I then put my camera between the laser level and the artwork I adjust the camera height and position so that the laser level's "plus" sign is on the back of the camera, just behind the center of the lens.

If I do this correctly, the camera is centered on the artwork, and perpendicular to it.

Interesting trick, but how does this method confirm the camera is parallel to the artwork? The projected crosshairs from the level would seem to only confirm the camera is in the middle of the level's projection but not necessarily parallel to the wall.

The key is to have a perpendicular line coming from the wall. In my case, the floor boards are perpendicular, and I use that as my reference.

Actually, you only need to mark two spots on the floor. The Centerline reference spot under the artwork, and a the Laser Level location, which must be on a line perpendicular to the Center Line Reference Spot.

In my studio, I have floorboards perpendicular to the wall. I use them as my reference.

When I hang the artwork, I am careful to center it left to right over the centerline.

I then adjust the height of the laser level so that it is centered up/down on the artwork.

I then position the camera so that the red plus from the laser level is centered behind the lens.

If you follow this steps, the camera will be aligned along the center projection of the laser level.

If the centerline on the floor is 90° from the wall, then you know you are parallel left to right.

We know that the laser level projects a level line, so we know the camera is not pointed up or down. Assuming the wall is actually vertical, we now know the centerline of the laser is perpendicular to the wall. As we are shooting along that line, we know the camera sensor must be parallel to the wall.

By the way, once you get everything parallel, you need to make sure your lighting is good, and your colors correct.

I have a colorchecker chart just next to the artwork. This gives me a good reference so I can get the colors right. I crop the colorchecker out for the final image. If artwork has a difference aspect ratio from your camera, there is usually somewhere to place the colorchecker.

For lighting, I use one studio strobe on each side of the artwork. The height of the strobe should match the horizontal laser line. The strobes should be about 45° out. I use 7" reflectors, and polarizing gels on the strobes. I use a polarizing filter on the lens. Rotating the polarizing filter on the lens allows me to control the amount of glare. Minimizing glare generally results in more accurate colors, higher contrast, and an overall increase in image quality.

Maybe it's just me, but this does not seem guaranteed to produce a yaw-free camera relative to the wall.

If the camera is aimed to the left, right, the artwork will not be centered.

If you have trouble centering the art in the frame, put an X on a Post-It® note, and stick that to the artwork where the laser lines intersect. Position the camera, and aim it such that the center focus point is overt the X. Remove the Post-It note and take the photo.

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Ellis Vener
Ellis Vener Forum Pro • Posts: 16,326
Re: Setting camera parallel to subject

Fo about twelve years I have  been using a Zig-Align system, http://www.zig-align.com , I hope they are still in business.

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Ellis Vener
Professional photographer since 1984.
To see my work, please visit http://www.ellisvener.com
Or on Instagram @EllisVenerStudio

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OP Tom Ferguson Senior Member • Posts: 2,320
Re: Setting camera parallel to subject
1

Ellis and a few others have suggested Zig Align. They are still in business. I looked into them a few years ago and decided (perhaps I misunderstood) that they were really for 4x5 cameras and enlargers, I "thought" you had to be able to "load" the mirror into the body. I see now that they have a system to put in front of a lens (like a filter).

My memory of Zig-Align led me to build a second version or my dual plastic mirror experiment, this time with Zig-Align like "target circles" and WOW, that did improve things. Quite easy to get real close to perfectly parallel

If I could do it all over again, I would just buy the Zig-Align. It isn't that expensive and I spent a fair bit in materials and TIME perfecting my DIY version!

Thanks to everyone for the help and suggestions.

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