Luminous Landscape Forum

Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: NaturePhotos on October 10, 2012, 03:28:14 pm

Title: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 03:28:14 pm
Sorry this is off-topic here, but searches seemed to indicate this would be the best forum to post this off-topic subject.  A friend asked me to photograph some of her paintings, and I've learned a lot (especially here) regarding lighting techniques, equipment choices, etc.  I'm primarily a nature photographer, but it seems like I have the gear to do a credible job.  I definitely don't want to stir up the MF vs SLR debate, but I'm using a D800e with the 85/1.8G at the moment for this task, and playing with cross-polarized SB-900s, though I'm not convinced the polarization is necessary for her work, which is matte finished with minimal brushstrokes.

I got unexpected feedback when she saw the results.  At 100%, the file shows the canvas texture perfectly, and that horrified her.  Hey, I thought lots of detail made for a great reproduction photograph.  Apparently not in the art reproduction world.  :)  I've played with lots of techniques to remove it, such as blurring, high pass filtering/masking, and FFT filtering.  The last was the most successful, but still obviously reduces the detail some, and is a guessing game.  She showed me results from some others she had done professionally before she moved to this area, and I see her point -- there is still high res detail, but the canvas texture has been mostly removed.

Can anyone help illuminate how to remove canvas texture in post processing, while retaining other details?  Or does the lighting need to be different?

Thanks in advance.




Title: Re: Photographing Artwork -- Canvas Texture
Post by: Ken on October 10, 2012, 03:56:07 pm
Try this: Flood the painting with equal flat (diffuse) illumination from top, bottom and both sides at about a 45-degree angle to the painting. Put a gray or lighter color flat (cardboard, paper, etc.) over the painting, or in place of it, and take meter readings top to bottom and side to side.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: Jeff Magidson on October 10, 2012, 04:12:22 pm
I got unexpected feedback when she saw the results.  At 100%, the file shows the canvas texture perfectly, and that horrified her.  Hey, I thought lots of detail made for a great reproduction photograph.  Apparently not in the art reproduction world.  :)  I've played with lots of techniques to remove it, such as blurring, high pass filtering/masking, and FFT filtering.  The last was the most successful, but still obviously reduces the detail some, and is a guessing game.  She showed me results from some others she had done professionally before she moved to this area, and I see her point -- there is still high res detail, but the canvas texture has been mostly removed.

Can anyone help illuminate how to remove canvas texture in post processing, while retaining other details?  Or does the lighting need to be different?

Thanks in advance.

Mark:

I have been photographing artwork full time for 15+ years for individual artists and major institutions. As long as you are not going way overboard with contrast or lighting to exaggerate the canvas texture, you are doing the photography correctly. A good digital capture is always going to show the canvas weave if it is visible in real life. Perhaps her previous photography was not shot with such a high MP camera as your D800e?
 
As for using polarization: I use it sparingly and doubt it would be needed for the artwork you described.

~ Jeff

http://artslidesboston.com
 

Title: Re: Photographing Artwork -- Canvas Texture
Post by: JeanMichel on October 10, 2012, 04:55:35 pm
Mark:

I have been photographing artwork full time for 15+ years for individual artists and major institutions. As long as you are not going way overboard with contrast or lighting to exaggerate the canvas texture, you are doing the photography correctly. A good digital capture is always going to show the canvas weave if it is visible in real life. Perhaps her previous photography was not shot with such a high MP camera as your D800e?
 
As for using polarization: I use it sparingly and doubt it would be needed for the artwork you described.

~ Jeff

http://artslidesboston.com



I agree with Jeff. ALthough, I often use cross polarized lighting to control and modulate the reflections on some paintings. I also always photograph a colour checker for each painting, and set colour balance manually.
Jean-michel
 


Title: Re: Photographing Artwork -- Canvas Texture
Post by: elolaugesen on October 10, 2012, 06:34:37 pm
I photograph and print for a few artists.
 
They all want to see any weave left and all the texture in their paintings.  They do not want me to get rid of it.  Only a few do not want the texture emphasised if possible.  The reason is that they were originally water colour painters and treat oil paintings in a very similar way.  They are very light on the paint and use oils the same way they did water colours.  If you saw their original work you would see the similarities.
Oil/acrylic painters tend to be heavy/solid/thick with the paint and create their own textures.  They do not depend on the canvas texture,
they make the canvas work for them.
All of the artists I work with want the prints to look like the original(minus the occasional drop of paint or so). 
Maybe your customer should not use such a textured canvas.  There are canvasses out there that are very/very smooth.

I let my other half deal with the artists when it comes to that kind of detail as she is an oil/mixed media painter(working artist) herself. 
I will discuss printing techniques and let her discuss art techniques and how to get better prints/results with the artists.
I always emphasise the teamwork and that we are there to create a product for them to sell and they certainly do not want me to dumb down their art.

cheers elo
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 06:59:14 pm
I would like to have four even light sources.  Unfortunately I only have two strobes I'm working with at the moment.  I'm shooting the paintings perfectly vertical, with the two strobes about 45 deg out, centered on the middle of the painting.

I've tried with natural light only, with strobes, with and without cross polarization, and find I'm getting pretty similar results.  I suspect a painting with large brushstrokes and a gloss finish would change the game quite a bit.

Thanks,
Marc
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 07:08:23 pm
I agree with Jeff. ALthough, I often use cross polarized lighting to control and modulate the reflections on some paintings. I also always photograph a colour checker for each painting, and set colour balance manually.
Jean-michel

Thanks, just ordered colorchecker, based on all the glowing reviews.  To date I've only been shooting a gray card in the image.  I'm finding better color converting the raws out of Nikon software (ViewNx) than ACR, but the reds are too hot.  So I'm hoping the colorchecker will resolve that issue.

Marc
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 07:14:33 pm
Mark:

I have been photographing artwork full time for 15+ years for individual artists and major institutions. As long as you are not going way overboard with contrast or lighting to exaggerate the canvas texture, you are doing the photography correctly. A good digital capture is always going to show the canvas weave if it is visible in real life. Perhaps her previous photography was not shot with such a high MP camera as your D800e?
 
As for using polarization: I use it sparingly and doubt it would be needed for the artwork you described.

~ Jeff

http://artslidesboston.com
 



Jeff,

That's really good to hear as a sanity check.  Thanks.

Some of her previous work was shot with a betterlight back at more than 500 dpi and shows no canvas texture, but I haven't seen the original...yet.  I will go see it soon -- very curious now.

Marc
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 07:18:42 pm
I photograph and print for a few artists.
 
They all want to see any weave left and all the texture in their paintings.  They do not want me to get rid of it.  Only a few do not want the texture emphasised if possible.  The reason is that they were originally water colour painters and treat oil paintings in a very similar way.  They are very light on the paint and use oils the same way they did water colours.  If you saw their original work you would see the similarities.
Oil/acrylic painters tend to be heavy/solid/thick with the paint and create their own textures.  They do not depend on the canvas texture,
they make the canvas work for them.
All of the artists I work with want the prints to look like the original(minus the occasional drop of paint or so). 
Maybe your customer should not use such a textured canvas.  There are canvasses out there that are very/very smooth.

I let my other half deal with the artists when it comes to that kind of detail as she is an oil/mixed media painter(working artist) herself. 
I will discuss printing techniques and let her discuss art techniques and how to get better prints/results with the artists.
I always emphasise the teamwork and that we are there to create a product for them to sell and they certainly do not want me to dumb down their art.

cheers elo

Cheers elo.  She's an oil painter, and I wouldn't dare tell her what to do, if you know what I mean.  But what you say makes perfect sense. 

Thanks,
Marc
Title: Re: Photographing Artwork -- Canvas Texture
Post by: elolaugesen on October 10, 2012, 07:38:07 pm
Watch color checker.    Tends to create very saturated images.  Even their advertising say that they create bright colourful images with a punch.     That is not what we want for art work.
.  For art work I am now looking at QPCARD

Look at some other discussions on this site.

Cheers
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 09:54:16 pm
Watch color checker.    Tends to create very saturated images.  Even their advertising say that they create bright colourful images with a punch.     That is not what we want for art work.
.  For art work I am now looking at QPCARD

Look at some other discussions on this site.

Cheers
Thanks, will do.  As long as the colors are properly balanced, can't we just take the sat or vibrance down a bit?  But I certainly would rather have it correct in-camera.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 10, 2012, 10:01:45 pm
Once I see the other painting in question (for which I have a copy of the betterlight scan at over 500 dpi, with little texture), if the naked eye shows obvious texture I'll get permission to post crops here.  If the canvas is consistent with her other painting that I have now, the photographer did something impressive to remove the canvas texture.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: hugowolf on October 10, 2012, 10:24:10 pm
Cross polarization works to cut reflections from the uneven texture of the canvas, but will not alleviate the shadows from the standard 45º repro lighting. If the canvas has a deep texture, then that is a problem.

Try moving the lighting closer to the focal axis (straighter on to the work) and using softboxes or other diffusers. Alternatively try using the lights bounced back from large white reflectors behind the camera.

Does the work have heavy impasto, if so that brings in other problems?

Usually, my clients want something of the canvas texture to show. On the rare occasions when this isn’t the case, I use two large rectangular softboxes with just enough room to put the camera between. Large sheets of polarizing film are expensive, but nowhere near the cost of other photo gear.
http://www.polarization.com/polarshop/

Brian A
Title: Re: Photographing Artwork -- Canvas Texture
Post by: phero66 on October 10, 2012, 11:31:23 pm
If you want to be in the same league as the betterlight users, or anyone else shooting art with MF or dSLR's with raw software that accepts input ICCs, then you should buy a Colorchecker "SG" chart.  They are not cheap, but its the best route for greater accuracy in color working with fine art.  They do not have a matte surface however, so greater care in lighting is required.

For software that won't break the bank take a look at Pictocolors "Incamera."  Its the same ICC input software that many betterlight users use.  On the far end of the $$$ spectrum is Monaco Profiler but its been off the market for a few years and harder to find.

-John
Title: Re: Photographing Artwork -- Canvas Texture
Post by: elolaugesen on October 11, 2012, 02:49:44 am
My other half read my comments.  
The texture showing mostly depends on the way the artist lays on the paint.  If Gessoed and prepared properly then rough textured and finely(portrait) textured canvas should be the same depending on how the paint is layed on.

I am interested in the polarization.  where can I find some good/simple info/learning material on this for the kind of work I do.  Paintings etc.?  I have had some issues with some gloss varnished paintings.

 for camera profiling and white balance      http://www.qpcard.com
 some people swear by them for colour accuracy.
 
cheers
Title: Re: Photographing Artwork -- Canvas Texture
Post by: Stephen G on October 11, 2012, 03:23:04 am
One of the most useful tricks I've learned in photographing paintings is to do it in same/similar light to that which the artist uses to paint. match spectrum, direction of light, colour temp as close as you can.

Example: I've got an artist who paints under a weird mix of flouro, tungsten and skylight. I shot one of her paintings under full cross-polarization and it revealed colours in her deep shadows that she's never seen in her paintings. No match, had to shoot again and simulate the light that she uses.

QPcard is great but takes some playing with LR settings to get a good starting point. I start with exposure at -1.00 and contrast at -31 with the calibration profile at High Contrast, Large Gamut (this makes sense when you play with the QPcard software)
Title: Re: Photographing Artwork -- Canvas Texture
Post by: elolaugesen on October 11, 2012, 04:26:44 am
Stephen:   Original Paintings..   

 I use ACR for my processing engine....   How do you find LR for doing this ...   My aim is to get the image to look exactly like the original image(98% - we can never get to 100%)  and I have some issues with all the features to make things look, punchier, more saturated etc etc.... 

all I want is what I and the artist see!

QPCARD how does the colors compare to previous tools?

I am just starting to look at it??
cheers elo

Title: Re: Photographing Artwork -- Canvas Texture
Post by: Stephen G on October 11, 2012, 05:18:48 am
Stephen:   Original Paintings..  

 I use ACR for my processing engine....   How do you find LR for doing this ...  


I haven't used ACR for this, but it should be the same as LR - same controls and same raw conversion engine.

Agree about the 98% - When I use the QPCard I use LR to get a good starting point and then I go into hard-proofing. Print, compare and take notes, adjust - repeat until you are satisfied. I can usually get to sign-off in 2-3 cycles. If you've got great monitor, well profiled and a good viewing environment then you can do a lot more on screen to save some ink and paper.

You can also use targets like the DCSG or HCT to build a camera profile for each shoot - this actually works better than the QPCard but needs profiling software.

Edit: the QPCard builds DNG profiles that I much, much prefer to those from the 24 patch colour checker / passport. Not just better colour - none of the over-saturated punchiness of the CC profiles - but a really nice tone curve too (choice of 3 actually). Great for general photography, especially BW work, I've found.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: hugowolf on October 11, 2012, 11:34:01 am
I am interested in the polarization.  where can I find some good/simple info/learning material on this for the kind of work I do.  Paintings etc.?  I have had some issues with some gloss varnished paintings.
It is quite simple. You use linear polarizing gels/film over the lights and a circular polarizer on the lens. You rotate the polarizer on the lens to vary the effect, which involves some trial and error if you are using flash and makes shooting tethered more important. It is imperative that the polarizing film on all the lights is aligned.

Brian A
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 11, 2012, 01:37:23 pm
It is quite simple. You use linear polarizing gels/film over the lights and a circular polarizer on the lens. You rotate the polarizer on the lens to vary the effect, which involves some trial and error if you are using flash and makes shooting tethered more important. It is imperative that the polarizing film on all the lights is aligned.

Brian A
I bought my polarizing film from the source Brian suggested above, and I bought it laminated to make handling easier.  I'm presently using a Hoya Pro1 CPL.

No discernible impasto on the painting I'm referring to.  Really this is a 2D exercise -- I'm sure other paintings are much more difficult to shoot.  I noticed very little difference with cross polarization in this example, but the essentially-2D surface is matte, so there were no highlights/hotspots to bring down anyway.  As an experiment, I suppose I should try shooting one of my glossy, liquid-varnished canvases (my own nature photography), though I suspect that's still nothing compared to 3-D heavy impasto.

Thanks to everyone for their feedback.  It sounds like I didn't do enough research for color profiling, so I'm off to read relevant threads there.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: RFPhotography on October 12, 2012, 08:26:21 am
If you're finding the profiles too saturated or punchy with the Color Checker software, then the Adobe software may be more to your liking.  It also gives you the option of different preset curves, including linear, or using your own custom curve.  It's not the completely automated approach of XRite. 
Title: Re: Photographing Artwork -- Canvas Texture
Post by: framah on October 12, 2012, 10:08:01 am
Personally, i agree that your main problem here is the lighting.  With lights at too much of an angle to the surface, you will get raking light which over emphasizes the texture, creating hills and valleys, so to speak.
You might also want to consider continuous lighting instead of strobes.  Strobes are pretty harsh for lighting art.  You can't set strobes next to the camera and not expect to get hotspots where they have blown out the image.I use a set of Northlights and a Betterlight scanback for my art shooting and, yes you will get canvas weave showing but if the lights are set right, it won't over power the image on the canvas.

Even with having to sharpen the Betterlight file, I have never had a problem with the weave overpowering the image as you mention.

Every artist I have shot for likes the realism of the reproduction showing the weave as if it were the original... so, either your artist is a "weirdo" or your lights are too harsh and raking. As another poster said big softboxes right next to the camera should solve that problem.
Another reason for continuous lighting is that you can more easily determine where your hotspot of light (where the two light cones overlap) is on the art and adjust for it.

As for fall off of the light in the corners (as well as the hotspot), there is software out there that allows you to compensate for it. It's called Equalight. You shoot the art and then you shoot a white board of the same file size and run the files thru the software and it adjusts your art file so the lighting is even. Check it out.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: darlingm on October 12, 2012, 11:38:17 am
. . .Hey, I thought lots of detail made for a great reproduction photograph.  Apparently not in the art reproduction world.  :). . .

Like others, I print for a lot of artists and everyone has been thrilled with the detail in the image showing canvas texture.  I make a selling point from paper prints still appearing like they're on canvas, since the digital file has that texture in it.  Out of curiosity, do you know why she doesn't like it?  When I made my first canvas print, I was worried I'd have a "double-struck" canvas weave look, and anticipated needing to remove the canvas texture.  Turned out to be a non-issue, unless you're blowing up the image substantially.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 12, 2012, 04:05:46 pm
Thanks again for the responses, everyone.  I value this forum a lot, and learn something useful almost every time I'm here. 

The way I see it, I'd be surprised to see too many artists wanting reproductions past 1:1 size.  So if the reproduction has infinite detail and lighting was proper at the time of shooting, it should basically look just like the original.  That is, it should look like the painting whether viewing at 1 foot or 20 feet, including texture and anything else.

One more general question.  Do you clone out all the dust, hair, etc. in your files?  That was probably my biggest surprise, i.e. just how much lint is caught up in the surface of the painting.



Title: Re: Photographing Artwork -- Canvas Texture
Post by: darlingm on October 12, 2012, 05:00:42 pm
Thanks again for the responses, everyone.  I value this forum a lot, and learn something useful almost every time I'm here. 

The way I see it, I'd be surprised to see too many artists wanting reproductions past 1:1 size.  So if the reproduction has infinite detail and lighting was proper at the time of shooting, it should basically look just like the original.  That is, it should look like the painting whether viewing at 1 foot or 20 feet, including texture and anything else.

One more general question.  Do you clone out all the dust, hair, etc. in your files?  That was probably my biggest surprise, i.e. just how much lint is caught up in the surface of the painting.

I go through the file at 100%, removing everything stuck to the painting that shouldn't be there.  I do all of my work in a new layer(s), so it's easy to remove or redo.  I also, at the artist's option, do some minor touchup work as well, such as if they've creased the canvas against the stretcher bars a bit.  I use a combination of several techniques, including cloning.  Again, it's at the artist's option, but I often go for artist's intent, and will patch up painting defects as well, like if there's a stray dot of paint where it shouldn't be.

For really sturdy paintings, I occasionally spray air on them to help get stuff stuck on it off.  You have to make sure the air pressure is really low, so you don't risk damaging the painting.  I have a nice compressor with an attachment that lets me tone down the pressure it lets out, so it's like I was blowing hard on a piece, but it saves my breath.  You also have to make sure you have a clean air source.  Canned compressed air can occasionally spray out liquid, so I wouldn't risk that.  Some air compressors send out very moist air, and others are better about filtering moisture out.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: elolaugesen on October 12, 2012, 05:17:41 pm
I will with the artist's agreement always remove small blemishes, dog hair etc. from the images before printing.
I very very rarely do anything to remove anything from the painting itself as you just never know exactly what the artist have used to create it and how they did it.  I have lived with a working artist for too many years
I once had to use a paint brush to recreate a black spot on a large sunflower painting that I framed after the photo shoot.
I called the artist and told her I had the black spot in my hand and she just said you know how to use a brush fix it!

the message here is...  get to know your client well?

cheers elo
Title: Re: Photographing Artwork -- Canvas Texture
Post by: Clearair on October 13, 2012, 02:44:52 pm
Art Repo'd a pano impressionistic landscape last year. Artist was shown to versions.
With full on detail, which did bring out the canvas texture more than you APPEAR to notice when looking at the original. You see in 3D when looking at the original after all and your focus is moving.
Next same detail but much less canvas showing. This was the preferred choice and sold well next to the original!! Well it was cheaper.


 All were printed on Hahnemuhle Bamboo which has a slight texture but is not canvas obviously (too much salt etc etc) and I played with moire filtering in my PP software to reduce any patterns like Dah Dahhh, canvas weave.

Works 4 me.

Regards 
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 13, 2012, 03:34:14 pm
Art Repo'd a pano impressionistic landscape last year. Artist was shown to versions.
With full on detail, which did bring out the canvas texture more than you APPEAR to notice when looking at the original. You see in 3D when looking at the original after all and your focus is moving.
Next same detail but much less canvas showing. This was the preferred choice and sold well next to the original!! Well it was cheaper.


 All were printed on Hahnemuhle Bamboo which has a slight texture but is not canvas obviously (too much salt etc etc) and I played with moire filtering in my PP software to reduce any patterns like Dah Dahhh, canvas weave.

Works 4 me.

Regards 

Hi Clearair,

Which PP software/moire filter would that be?

Thanks.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: Clearair on October 15, 2012, 04:44:21 pm
Hi

Sorry for delay. I use Aperture, so played with the settings and was pleasantly surprised.
Don't recall using PS at all or anything else.
Give it a whirl.

Regards all......
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 15, 2012, 05:21:16 pm
Hi

Sorry for delay. I use Aperture, so played with the settings and was pleasantly surprised.
Don't recall using PS at all or anything else.
Give it a whirl.

Regards all......
Thanks.  Unfortunately I don't have a Mac to give it a try.  I did try the moire filter in Capture One, but found it had absolutely no effect on texture.
Title: Re: Photographing Artwork -- Canvas Texture
Post by: Clearair on October 17, 2012, 10:09:55 am
I have no idea why it worked, if the pattern of the weave in the painting or something in Apertures way of dealing with moire.......??  Not had to try this since
but wanted you to give it a try just to see if it helps.

Regards
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 17, 2012, 11:24:01 am
Thanks.  The only tool I have with moire correction is Capture One.  I was hoping for similar results as you reported with Aperture, but found it had absolutely zero effect on texture, at any setting.  Clearly different software tools are going after moire correction in different ways.


Title: Re: Photographing Artwork -- Canvas Texture
Post by: Mike Guilbault on October 18, 2012, 11:59:08 pm
I've quite often, and successfully, used the Dust & Scratches option in PS to reduce the effect of visible canvas weave.  You have to play with the settings, especially the Threshold, to affect the weave but leave the painting as original as possible. The artists that I've done work for seem to love it - if they don't want the weave to show that is.  Some artists like the weave left in.
Shooting with a D800e, 85mm PC lens, two Photogenic strobes in umbrellas at approx. 45 degrees to painting.  Check all four corners and centre of the painting with handheld light meter to create even exposure, usually within 1/10th of a stop.  If there's lots of texture in the painting, I'll bump up the power on one light to create some dimension (soft shadows).
Title: Re: Photographing Artwork -- Canvas Texture
Post by: NaturePhotos on October 19, 2012, 04:18:58 pm
I've quite often, and successfully, used the Dust & Scratches option in PS to reduce the effect of visible canvas weave.  You have to play with the settings, especially the Threshold, to affect the weave but leave the painting as original as possible. The artists that I've done work for seem to love it - if they don't want the weave to show that is.  Some artists like the weave left in.
Shooting with a D800e, 85mm PC lens, two Photogenic strobes in umbrellas at approx. 45 degrees to painting.  Check all four corners and centre of the painting with handheld light meter to create even exposure, usually within 1/10th of a stop.  If there's lots of texture in the painting, I'll bump up the power on one light to create some dimension (soft shadows).

Mike,

Thanks.  That with a little large radius sharpening to bring back edge contrast seems to work pretty well on the image I'm playing with (bowl of large fruit against dark background).

Marc