Digital capture / Time-lapse video recording of Art using Samsung SL202

writes:

Digital capture /time-lapse recording of arcylic paintings
Greetings,

Could someone help me with simple instructions to shoot an acrylic
original painting using a Samsung 10.2 MP (model SL202 if that
matters?) The purpose is to e-mail a customer how their painting is
coming up, not for production quality reprint (which I take to a
professional photographer).

I have had two challenges that mars the pictu

1. The square frame seems oblongated towards the sides (like the pics
you get from cell phone capture)

I'm not at all sure I understand this description. Do you mean that
"straight" lines towards the edges of the frame bow outwards? (If so,
the term of art is "barrel distortion"; the opposite, where they bow in,
is "pincushion distortion".)

Try different zoom settings; the degree of such distortion in most zoom
lenses varies with the focal length. There's likely to be some length
at which it doesn't have much of any.

Alternatively, it can be corrected in software. Photoshop (perhaps
Elements too), PTLens, many others. (Look for "lens correction" and
"barrel", if nothing comes up that program may well not handle it.)

2. The acrylic paint surface creates a diffused glare -- this is
especially true if I finish the painting with matt or gloss varnish to
seal the painting.

Any surface has a range of angles in which it gives specular reflections
(glarey-type reflections). If the surface is reasonably flat, just
arrange that the lighting is at angles to the camera where it doesn't
glare at the camera (this may require covering windows, etc.). If the
surface is very uneven with bits facing every which way, this is much
harder, but you describe a kind of overall glare, which suggests a
flatter surface. And what I know of acryllic painting tends towards a
flatter surface (than modern uses of oils for example).

Yeah, if you plan to take frequent, even constant, pictures documenting
the creation of the painting, it would be a real total pain to have to
mess with the lighting for each picture. Sorry about that. I don't
know any magic way to make glare go away. Well, except the following:

A more drastic approach, and I suspect even less useful for the
documentary purpose you describe, is to light the artwork only with two
lights, out to the sides at 45 degrees to the surface, each equipped
with a polarizing filter, oriented the same way. Then put a polarizing
filter on the lens of the camera, oriented to block the glares from the
polarized light. The diffuse reflection will not be polarized and will
get through.

(Skipping the video question, no good answer here.)
--
David Dyer-Bennet, ; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info

On 2012-02-13 13:31:16 -0800, David Dyer-Bennet said:

writes:

Digital capture /time-lapse recording of arcylic paintings
Greetings,

Could someone help me with simple instructions to shoot an acrylic
original painting using a Samsung 10.2 MP (model SL202 if that
matters?) The purpose is to e-mail a customer how their painting is
coming up, not for production quality reprint (which I take to a
professional photographer).

I have had two challenges that mars the pictu

1. The square frame seems oblongated towards the sides (like the pics
you get from cell phone capture)

I'm not at all sure I understand this description. Do you mean that
"straight" lines towards the edges of the frame bow outwards? (If so,
the term of art is "barrel distortion"; the opposite, where they bow in,
is "pincushion distortion".)

I have a feeling that Uma Sundaram is describing is a "Keystone" effect
where the top and bottom edges of a rectangular frame are not the same
length.
http://en.wikipedia.org/wiki/Keystone_effect

This can be corrected with the lens correction filter in Photoshop,
adjusting the vertical and/or horizontal perspective. However it might
be best to ensure that the camera is positioned center and
perpendicular to the subject painting.
There are quite a number of examples of time lapse work of this sort to
be found on Youtube.

http://www.youtube.com/results?searc...1108l0.4.2l6l0

or
http://tinyurl.com/7hk269v




Try different zoom settings; the degree of such distortion in most zoom
lenses varies with the focal length. There's likely to be some length
at which it doesn't have much of any.

Alternatively, it can be corrected in software. Photoshop (perhaps
Elements too), PTLens, many others. (Look for "lens correction" and
"barrel", if nothing comes up that program may well not handle it.)

2. The acrylic paint surface creates a diffused glare -- this is
especially true if I finish the painting with matt or gloss varnish to
seal the painting.

Any surface has a range of angles in which it gives specular reflections
(glarey-type reflections). If the surface is reasonably flat, just
arrange that the lighting is at angles to the camera where it doesn't
glare at the camera (this may require covering windows, etc.). If the
surface is very uneven with bits facing every which way, this is much
harder, but you describe a kind of overall glare, which suggests a
flatter surface. And what I know of acryllic painting tends towards a
flatter surface (than modern uses of oils for example).

Yeah, if you plan to take frequent, even constant, pictures documenting
the creation of the painting, it would be a real total pain to have to
mess with the lighting for each picture. Sorry about that. I don't
know any magic way to make glare go away. Well, except the following:

A more drastic approach, and I suspect even less useful for the
documentary purpose you describe, is to light the artwork only with two
lights, out to the sides at 45 degrees to the surface, each equipped
with a polarizing filter, oriented the same way. Then put a polarizing
filter on the lens of the camera, oriented to block the glares from the
polarized light. The diffuse reflection will not be polarized and will
get through.

(Skipping the video question, no good answer here.)


--
Regards,

Savageduck

Savageduck writes:

On 2012-02-13 13:31:16 -0800, David Dyer-Bennet said:

writes:

Digital capture /time-lapse recording of arcylic paintings
Greetings,

Could someone help me with simple instructions to shoot an acrylic
original painting using a Samsung 10.2 MP (model SL202 if that
matters?) The purpose is to e-mail a customer how their painting is
coming up, not for production quality reprint (which I take to a
professional photographer).

I have had two challenges that mars the pictu

1. The square frame seems oblongated towards the sides (like the pics
you get from cell phone capture)

I'm not at all sure I understand this description. Do you mean that
"straight" lines towards the edges of the frame bow outwards? (If so,
the term of art is "barrel distortion"; the opposite, where they bow in,
is "pincushion distortion".)

I have a feeling that Uma Sundaram is describing is a "Keystone"
effect where the top and bottom edges of a rectangular frame are not
the same length.
http://en.wikipedia.org/wiki/Keystone_effect

In which case "keystone" and "perspective correction" are the keywords
I'd use to find stuff on it.

Or just arrange to have the camera square to the frame; however, having
the camera NOT square to the frame may help resolve the glare problem.
Might be easier to shoot from an angle and correct the perspective
later.

Problems tend to interact; sigh.

This can be corrected with the lens correction filter in Photoshop,
adjusting the vertical and/or horizontal perspective. However it might
be best to ensure that the camera is positioned center and
perpendicular to the subject painting.

I see great minds are running in the same rut again.
--
David Dyer-Bennet, ; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info