Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

how to photograph my small paintings
Post new topic   Reply to topic
Home   Techniques
View previous topic :: View next topic  


PostPosted: Thu Aug 13, 2009 2:01 pm    Post subject: how to photograph my small paintings Reply with quote
Hello eb
i have some small paintings made by me in acrylic, size small 10x15 or 13x18 all painted on canvass board.
i would like to create a web page with the related pics of each one of the paintings...
does anyone knows how to do it ? or give me some suggestions to take pics with good light? (in studio)
thanks a lot in advance

paolo Smile


PostPosted: Thu Aug 13, 2009 3:01 pm    Post subject: Reply with quote
Lefkowitz, Lester, "The Manual of Close-Up Photography", Amphoto N.Y., 1979, ISBN 0-8174-2130-0


PostPosted: Thu Aug 13, 2009 5:24 pm    Post subject: Re: how to photograph my small paintings Reply with quote
mybike wrote:
Hello eb
i have some small paintings made by me in acrylic, size small 10x15 or 13x18 all painted on canvass board.
i would like to create a web page with the related pics of each one of the paintings...
does anyone knows how to do it ? or give me some suggestions to take pics with good light? (in studio)
thanks a lot in advance

paolo Smile


The best suggestion I can give is to light them exactly as they were lit when painted.

Here's some luck! I have found photographing paintings very difficult, especialy getting colors correct. Another suggestion after setting up lighting is to photograph a grey card placed over the painting to use for custom white balance, as a starting point for correcting colors.

One problem with digital cameras is they use RGB colorspace; CMYK film colorspace is closer to painting imho...


PostPosted: Thu Aug 13, 2009 5:35 pm    Post subject: Reply with quote
hi Paolo
you need first to find which one of your lenses has the less gemoetrical distortion.
This is important if you don't want to have curved margins of the paintings.
You will need of course a tripod for the camera and one for the painting, unless you decide to shoot the painting on the floor, which can be difficult because of the shadows of the camera tripod.
You will need to set both tripods perfectly perpendicular to the ground by use of a bubble (spirit) level.
This way the lens will be perfectly perpendicular to the painting's surface.
You need to place camera's height according to the painting, the lens should aim to the perfect centre of the painting.
Since your camera and painting are perfectly aligned, you will not have to stop down much to ensure everything is in focus. Just stop down to what is the sweet spot of your lens (typically around f/5.6)
The best location to shoot your paintings is either outdoors in a cloudy day, or outdoors under a big tent (you dont need to buy one, you can build one by use of four tall poles on the top of which you secure the four corners of a large white cotton bed sheet (those for two places beds), or indoors in a room that is lightened indirectly (with lights pointing to the ceiling which reflects light back in a diffused way). Never use direct lights pointed to the painting.
If you shoot digital, have ready a large white cardboard to put in front of the painting, you will shoot it before every painting so you will have a white balance reference to use for doing correct RAW developing.
Always shoot RAW never JPG
To meter the light, do not use camera meter. Use hand held meter instead, and either measure incident light, or use a 18% grey card directly in front of painting to meter reflected light. This means of course you will have to use the camera in manual mode.
Other obvious suggestions: always remove any glass that might be in the paintings' frame, and never, ever use flash, because the surface of oil paints is reflective and you will never be able to avoid highlights reflections if you use flash. The best way is what I said before, that is ambient diffused light (either natural or continuous bulb).
hope this helps


PostPosted: Thu Aug 13, 2009 6:23 pm    Post subject: Reply with quote
I have done plenty of flat copy work over the years, here is the method I use for larger paintings, but can of course be scaled-down for smaller originals.

First I need to know the original is evenly lit. I use two photofloods, positioned to the left and right of the original at 45-degrees pointing at the middle, with the axes at the same height. To test for eveness, I use a small object like a roll of 120 film (you can use whatever is convenient, a BIC lighter, an AA-size battery or whatever), place it at the middle perpendicular to the original. If the original receives equal illumination from both photofloods, the two shadows would be the same in intensity, and if their positions are correct, both shadows would line up in a straight line. Make sure you place the lamps at fair distances away from the original to prevent hot spot in the middle.

The camera has to be positioned to have its optical axis perpendicular to the original and hits it at its dead centre. This can be a bit tricky to do, a method is to place a mirror at the middle and if you can see the camera lens in the mirror then you would be very close to the correct position.

Although the original is meant to be flat, oil and acrylic paintings are slightly three-dimensional, with plenty of inclined surfaces. While the lamps are positioned not to make reflections from the general flat surface of the painting, these small inclined surfaces would indeed produce reflections. As a rule, I place polarizing filters both on the lamps and the camera lens: the ones on the lamps are identically positioned, and the one on the lens positioned to give maximum polarization; this would get rid of all the reflections and bring out the true colours.


PostPosted: Thu Aug 13, 2009 6:57 pm    Post subject: Reply with quote
put them on flat scanner and scan Rolling Eyes


PostPosted: Fri Aug 14, 2009 2:55 pm    Post subject: .. Reply with quote
really thanks to eb! your' great to help me and i appreciate
all the methods are good , i think, i just try out one by on eto see which one gives the best perfromance for this purpose
just one more tip: the paintings are painted above the acryilic with a particular bright and trasparent paint to give more strenght to original dull acriylic colours. The only problem is that this can cause some reflections. do you think this fact is to be taken in account ?


PostPosted: Fri Aug 14, 2009 3:48 pm    Post subject: Reply with quote
Paolo,

The method I described using cross-polarized light would take away all the reflections.

There was only one occasions where my method did not work: on the painting itself there were metallic flecks embedded, and the polarized light took away the metallic look too. But if I did not use the polarizers, the painting surface would get covered in reflections; too bad the painter did not understand any of it Sad


PostPosted: Sat Aug 15, 2009 7:19 am    Post subject: Reply with quote
poilu wrote:
put them on flat scanner and scan Rolling Eyes


+1
they are not large. This will be best absolutely so.


PostPosted: Sat Aug 15, 2009 9:02 am    Post subject: Reply with quote
Once you've sorted out the right lens for the job you might want to try some natural lighting, as in that lovely flat and minimal glare lighting you get on an overcast day. Years ago I used to do lighting for live music and occassionally integrate slide shows into the light shows with pictures sourced from magazines and similar glossy prints.


PostPosted: Sat Aug 15, 2009 11:12 pm    Post subject: Re: how to photograph my small paintings Reply with quote
siriusdogstar wrote:

One problem with digital cameras is they use RGB colorspace; CMYK film colorspace is closer to painting imho...


No it isn't. That's a wildly inaccurate statement, actually. Perhaps you are thinking of the process of paint mixing, which is certainly not colorimetric. But the capture of the resulting mixed colours does require colorimetric capture.

Although RGB is a colorimetric colourspace, the sensor itself is not colorimetric. Which does give rise to some problems in the accurate capture of a range of colours, particularly purples.

Your suggestion to light them exactly as they were when painted is however spot-on. This will reduce any colour shifts due to metamerism.


PostPosted: Sun Aug 16, 2009 3:46 am    Post subject: Re: how to photograph my small paintings Reply with quote
ChrisLilley wrote:
siriusdogstar wrote:

One problem with digital cameras is they use RGB colorspace; CMYK film colorspace is closer to painting imho...


No it isn't. That's a wildly inaccurate statement, actually. Perhaps you are thinking of the process of paint mixing, which is certainly not colorimetric. But the capture of the resulting mixed colours does require colorimetric capture.

Although RGB is a colorimetric colourspace, the sensor itself is not colorimetric. Which does give rise to some problems in the accurate capture of a range of colours, particularly purples.

Your suggestion to light them exactly as they were when painted is however spot-on. This will reduce any colour shifts due to metamerism.


My digital cameras have a Bayer Filter layer in front of the pixel photocells. Bayer Filters consist of RBG...

It is possible to mix colors not in RGB colorspace. Some purple is one, as you point to.

The Artist wanted a print. I had been painstaking in getting color balance exactly right. I took some print samples over for approval. She almost immediately pointed out two things. One, a reflection of vegetation on the water wasn't on the photograph at all! Two, of all the colors on the painting, one color was off, all the others were spot on! I should maybe also mention she does specific paintings for people to help them balance their energies, create a sense of calm and well-being, so the overall vibration of the painting, especially the colors, has to be balanced correctly, or it doesn't work, can even cause subtle side-effects. Okay, that probably sounds far-fetched. Anyway, just this one color was off, the rest were perfect.

The first problem was fixed by photographing the painting in the same lighting it was painted. The second was driving me crazy trying to PP, until I thought to try film instead of digital. It worked!

Thank you for the word "metamerism." I am fascinated by these knowledges. I'm currently researching the best method of simulating the eyesight of creatures with visual pigments sensitive to light in a different part of the spectrum. Human vision being most sensitive to green, some creatures have the same or better sensitivity to other colors, such as yellow or blue or purple. Of course mapping say, yellowspace to greenspace, is relatively easy, there are creatures, some squid for example, with multiple colors sensitivity, how to map that so a human can see it?


PostPosted: Sun Aug 16, 2009 7:55 am    Post subject: Re: how to photograph my small paintings Reply with quote
siriusdogstar wrote:
ChrisLilley wrote:
siriusdogstar wrote:

One problem with digital cameras is they use RGB colorspace; CMYK film colorspace is closer to painting imho...


No it isn't. That's a wildly inaccurate statement, actually. Perhaps you are thinking of the process of paint mixing, which is certainly not colorimetric. But the capture of the resulting mixed colours does require colorimetric capture.

Although RGB is a colorimetric colourspace, the sensor itself is not colorimetric. Which does give rise to some problems in the accurate capture of a range of colours, particularly purples.

Your suggestion to light them exactly as they were when painted is however spot-on. This will reduce any colour shifts due to metamerism.


My digital cameras have a Bayer Filter layer in front of the pixel photocells. Bayer Filters consist of RBG...

Yes, both true statements. So one would assume a Bayer digital camera is a colorietric capture device.

However, it turns out that the image capture phase is not colorimetric. See for example Francisco Martínez-Verdú et. al Concerning the calculation of the color gamut in a digital camera, Color Research and Application, 35:2, 399-410, 2006.

siriusdogstar wrote:
It is possible to mix colors not in RGB colorspace. Some purple is one, as you point to.

Purple is produced in RGB by mixing red and blue.

siriusdogstar wrote:
[The first problem was fixed by photographing the painting in the same lighting it was painted. The second was driving me crazy trying to PP, until I thought to try film instead of digital. It worked!

Yes, different systems have different colour gamuts. And yes, accurate simultaneous reproduction of colours is a non-trivial problem. I don't dispute that. Just that your characterization of the reason for those differences was inaccurate.

siriusdogstar wrote:
[Thank you for the word "metamerism." I am fascinated by these knowledges.

No problem. The wikipedia article on metamerism is not too bad.

siriusdogstar wrote:
I'm currently researching the best method of simulating the eyesight of creatures with visual pigments sensitive to light in a different part of the spectrum. Human vision being most sensitive to green, some creatures have the same or better sensitivity to other colors, such as yellow or blue or purple. Of course mapping say, yellowspace to greenspace, is relatively easy, there are creatures, some squid for example, with multiple colors sensitivity, how to map that so a human can see it?


That is indeed a hard problem. Its fairly easy to convert a measured reflectance system to a 'cone colourspace' and from there to calculate things like minimum resolvable colour differences. Its harder to apply much of current colour science, which is almost exclusively based on the 1931 characterization of a standard human observer for 2 degree (mostly foveal) colour vision. And mapping the resulting colours into colours that humans can see, as a false colour visualisation, does not really tell us how other animals 'see'. It does allow some patterns to be made visible (e.g. patterns on flowers that are only visible if parts of the ultraviolet spectrum are considered).


PostPosted: Sun Aug 16, 2009 8:19 am    Post subject: Re: how to photograph my small paintings Reply with quote
ChrisLilley wrote:

However, it turns out that the image capture phase is not colorimetric. See for example Francisco Martínez-Verdú et. al Concerning the calculation of the color gamut in a digital camera, Color Research and Application, 35:2, 399-410, 2006.


Another reference, this one with the whole paper available online, is the paper on Capture Color Analysis Gamuts by Jack Holm.

paper,
slides


PostPosted: Thu Aug 20, 2009 7:17 pm    Post subject: Re: how to photograph my small paintings Reply with quote
ChrisLilley wrote:
ChrisLilley wrote:

However, it turns out that the image capture phase is not colorimetric. See for example Francisco Martínez-Verdú et. al Concerning the calculation of the color gamut in a digital camera, Color Research and Application, 35:2, 399-410, 2006.


Another reference, this one with the whole paper available online, is the paper on Capture Color Analysis Gamuts by Jack Holm.

paper,
slides


Thank you very much for the links and information!

Here is links to The Secret World of Shrimps: Polarisation Vision at Its Best and Weird Shrimp Has Astounding Vision. "they see the world in 11 or 12 primary colours" in addition to detecting both linear and circular polarizations(!!!)[/url][/i]
Post new topic   Reply to topic
Home   Techniques
Page 1 of 1