Accurate Representation

[happyhippy]

I have a problem

I have to take photos of 150 oil on canvas paintings in 2 weeks .
The photos are for an art brochure of some kind and will be printed at A4.

For lighting I am using pollarized tungsten light and obviously a pollarizer on my camera. I will be using my newly aquired Canon 400D and the kit lens (I am saving for a new lens atm).

My problem is getting the exposure right, I am using the camera on manual and built in light meter says 1 sec at F8 100ISO when I point it at my grey card but when I view these later it seems a bit dark. I am dubiious of ajusting them by eye as my monitor isn't amazing.

Do you think if I incorporated grey, white and black cards somewhere around the edge of the frame and left the pictures in RAW the printers would grade it themselves? I am not sure which printer we will be usung yet so I cant ask them.

Chears

 

[Alpha]

1) Why are you polarizing the light source if you've got a polarizer on the lens. The only thing that does is make you lose a lot of light. You're already losing half of it by polarizing the light source, then another fraction of that depending on the angle of reflection when it hits the polarizer on your lens.

2) Include a calibrated color and/or gray card off to the side. White balance off the gray card pre-shot and color-balance off the color card in post.

 

[JerryPH]

Forget the light unless its in a place where the quality of the light is not even, even if it is VERY low.

If it is low but even, place the camera on a tripod, use a long shutter speed and shoot away. Extra lights give shadows, if you are not good at it.

Shoot RAW and adjust WB in post processing.

 

[happyhippy]

1) Why are you polarizing the light source if you've got a polarizer on the lens.

I thought that regular tungsten light isn't polarized so the filter would have no effect?

They want a small amount of shadow to bring out the relief.

I was more worried about getting the brightness right so that the images look exactly the same as the painting. If I left an 18% grey card at the side would the printer be able to adjust the exposure to that? Or could I do that on photoshop?

 

[Flash Harry]

seems to me that you know little about photography have a crappy uncalibrated monitor and are about to take on a commercial shoot with sub standard equipment, printers will print what you give them, you're the tog, sort your gear and give them corrected images. H

 

[frXnz kafka]

I thought that regular tungsten light isn't polarized so the filter would have no effect?

They want a small amount of shadow to bring out the relief.

I was more worried about getting the brightness right so that the images look exactly the same as the painting. If I left an 18% grey card at the side would the printer be able to adjust the exposure to that? Or could I do that on photoshop?

The printer is going to put out whatever you put in (maybe with come color shift, but your printer isn't going to fix your exposure).

You don't really need a gray card, especially if you're shooting digital. I'm not going to get into the lighting, because I don't know enough about it, but just meter with the camera. If the shot looks dark on the screen, adjust your shutter speed. I think you're way over-thinking this.

 

[confucious]

I have the same Canon you do, and I find that in full manual, center weighted, I have to underexpose a little to get the "right" exposure. IN other words - the Camera always says I am underexposing by 1-2 stops...but it is always wrong

So - set your light so the art is lit how you want (for relief etc.), put your cam in manual, Raw, center weighted metering, however many autofocus points you want, ISO 100, and set your white balance for best results. Do a few at different exposures (I don't think you'll be changing Aperture, about 4 stops from max. should be the sweet spot), take them home and fix the white balance in your free camera software. Take a range of images, put them on a USB and go get them printed to see what values you like best.

If you are doing 150, than it is worth making sure they are all done properly.

By the way - I know this is beyond your control at the moment, but the kit lens is pretty horrible!!! A cheap Canon 1.8 would get you 100% better results!

And of course, use a tripod and remote shutter, especially if you have to have one second long exposures!

Good Luck

 

[CanAm]

By the way - I know this is beyond your control at the moment, but the kit lens is pretty horrible!!! A cheap Canon 1.8 would get you 100% better results!

The kit lens isn't that bad. One of my close friends has taken 4,000 photos with the 18-55 kit lens and most of them came out great.

Also, the problem he's having has nothing to do with the lens. 1.8 is too big an aperture to take good pictures of canvases.

I say shoot at F/8 or F/11 with camera on AV and adjust EV accordingly.

 

[confucious]

Perhaps my kit lens was a poor representative of the rest of them, who knows

As to Aperture - I didn't suggest he SHOOT at 1.8, just that perhaps that would be a better lens for this kind of thing. The sharpness, colour, Bokeh, image period is far better with that lens, and it's cheap Even with the nifty-fifty I'd suggest he shoot 4-6 stops higher that wide open.

 

[JerryPH]

I have the same Canon you do, and I find that in full manual, center weighted, I have to underexpose a little to get the "right" exposure.

Thats the issue, center weighted... if you are focusing on someone with a dark T-shirt of course the rest of your picture will be over exposed. You want a setting that averages out instead of focusing the metering on one small part of the pic.

 

[JerryPH]

The kit lens isn't that bad.

Depends for who and what your goals are. Compared to a P&S, the kit lens does well... but for someone serious about their quality, its quite lacking in sharpness and quality of output. There is a reason it is inexpensive, the quality of the glass is poor compared to a faster/more expensive lens.

Thats not an insult, thats a fact. You cannot compare a Yugo to a Cadillac and expect the same performance or comfort.

 

[confucious]

Thats the issue, center weighted... if you are focusing on someone with a dark T-shirt of course the rest of your picture will be over exposed. You want a setting that averages out instead of focusing the metering on one small part of the pic.

gaaahhhh - I am silly. Of course that's it - I never even thought of it, and tend to always leave the cam on Center weighted. So it's NOT my Camera, it's me

 

[happyhippy]

Thanks for all the advice! I am completely pennyless at the moment so I cant really afford a new lens at the minute but I understand that it isn't the most amazing piece of kit in the world .

I think I've been rather stupid when it come to the grey card thing. I don't think I actually need it, I can just set the white and black point correctly in curves and that will give the same effect.

I'm still not sure about the polarizing thing though. Surely if you light something with polarized light then cancel that at the camera you loose all glare and reflections leaving just whats on the canvas?

 

[confucious]

I'm still not sure about the polarizing thing though. Surely if you light something with polarized light then cancel that at the camera you loose all glare and reflections leaving just whats on the canvas?

I am not entirely sure either, but let me have a go:

A polarizing filter is used, among other things, to cut out glare/reflection on glass, ice, metal...perhaps even just things? It is not dependent upon the light source being polarized, people seem to use it everywhere (unless sunlight is polarized...). So - couldn't you dispense with the polarized light source and just use the polarizing filter? This would provide much more available light, and should still get rid of any glare.

Once again - I am venturing into something I know nothing about, so please someone correct me if I am wrong.

 

[CanAm]

Depends for who and what your goals are. Compared to a P&S, the kit lens does well... but for someone serious about their quality, its quite lacking in sharpness and quality of output. There is a reason it is inexpensive, the quality of the glass is poor compared to a faster/more expensive lens.

Thats not an insult, thats a fact. You cannot compare a Yugo to a Cadillac and expect the same performance or comfort.

Maybe I'm not a camera snob, but I tend to look at the quality of the picture in how it was taken and its composition and not the gear used to do it.

Just because someone doesn't have the top of the line stuff doesn't mean they're not serious. Maybe some of us can't afford to put down 2,000 dollars on a lens alone. Maybe some of us don't have 3,000 dollars to waste on a camera. I seem to do just fine with an outdated camera and an 80 dollar lens.

I don't know about you, but my pictures come out sharp and clear with what I use.

I suppose you think decent photos were non existent before all this pricey stuff came out?