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termina3
Oct 29, 2008, 09:06 PM
Hey guys,

I've been asked to get a simple photo of two paintings for a brochure.

The kicker is that it needs to be 350dpi, 9.5x12in.

How does that translate to pixels? Would I be able to do this with a D300 or D3?

If you use math, please show it.

Thanks,

Termina3



termina3
Oct 29, 2008, 09:12 PM
OK…*I kinda answered my own question.

I need an image 3325px by 4200px (each measurement*350dpi).

Looking at file sizes for both the D300 and D3, neither quite get there.

Where can I get my hands on a camera that'll meet this capacity?

-T

Mr. G4
Oct 29, 2008, 09:14 PM
In photoshop when you create a new document just type in those number and you will get 3325 by 4200 pixels. No math involved...unless I'm completely wrong.:D

Shoot in raw and when you developed it upscale it in cameraraw to the dimension you want.

jake-g
Oct 29, 2008, 10:23 PM
You simply upsample the image. Either camera will get you there easily resolution-wise. The real trick will be using the correct lighting to get close to actual colors. Art repro done correctly is very difficult.

FrankieTDouglas
Oct 30, 2008, 12:12 AM
Angle two strobes to each side of the work, center of the piece in height. Have the strobes nearly firing directly at each other, but turned slightly into the painting. If you space them back enough, you will produce even lighting for the image. Process them in raw as the same color temperature as the lights. You should be relatively close then. Scale your image up in Photoshop or genuine fractals or some other software.

Abstract
Oct 30, 2008, 12:26 AM
Here is (possibly) a bad suggestion: photo merging?


A D300 has 4288 x 2848 pixels, which surpasses your requirement in one direction, but not the other. You're very nearly there anyway, although it will be hard to merge the photo without re-angling the camera. You could just lower or raise the camera while its on its tripod, but it would be hard to adjust the camera height-wise without moving left--right unless you have the proper type of tripod.

anubis
Oct 30, 2008, 01:21 AM
You simply upsample the image. Either camera will get you there easily resolution-wise. The real trick will be using the correct lighting to get close to actual colors. Art repro done correctly is very difficult.

Agreed... resolution should be the least of your worries... accurate color reproduction is hard.

termina3
Oct 30, 2008, 06:53 AM
As far as lighting, I have access to two what I consider "regular" lights (they're flashes but not strobes… studio lighting… details coming…) and two SB-800s and one SB-600.

I've heard two strobes on either side…*which I like. These paintings are very large (bigger than me); should I just scale that same solution to the larger painting?

ChrisA
Oct 30, 2008, 11:00 AM
Hey guys,

I've been asked to get a simple photo of two paintings for a brochure.

The kicker is that it needs to be 350dpi, 9.5x12in.

How does that translate to pixels? Would I be able to do this with a D300 or D3?

If you use math, please show it.

Thanks,

Termina3

You are going to need more pixels then you can get with a Nikon SLR. You can get those by "up scaling" the image in Photoshop but if your client knows what's up and has some experience he will be on to that trick.

How many pixels do you need. Well you answered your own question 350 pixels per inch for 12 inches is 350x12 in the other direction it's 350x9.5 so your final image will be 3325 x 4200 pixels or about 14 "mega pixels" You would actually need a camera with a sensor that is a little larger then that so there is room tofor slight clopping and straighting or to corect out any lens distortions.

The kind of work is NOT typically done with a Nikon/Canon style dSLR. That kind of camera is just not well suited to this kind of work. Your best best is to rent some higher end equipment. You can rent a Mamiya or Hasselblad system for not that much money. These cameras have very large sensors with high pixels counts and have MUCH lower noise and better color fidelity then any Nikon or Canon SLR. Typical specs are 24 to 30 megapixels and a sensor size twice as large as a 35mm film frame.

About lighting. The camera will be very carfully centered over the artwork and very carfully aligned so the lens is exactly square to the plane of the painting. Use two lights each aimed at the centers of the artwork such that the beam of light hits at 45 degrees. Each light will have some right to left or left to right fall off but the two will cancel each other. 45 degrees also will minimise reflections Turn out the other lights in the room or at least dim them way down.

Color balance is very critical here. You have to get it right. But it is very easy. After you are set up replace the artwork with a kodak "grey card" and photograph the card. Adjust the exposure so that the card comes out as an exact mid tone. Shoot a color chart next. Check the histograms see that everything is in bounds and not clipped. Finaly shoot the artwork.

You want to be working in raw format for all of these shots so that you can do tha final color balance on the computer. Getting it right is "way easy" now that you have white, grey and black from your grey and color cards. You can work "by the numbers" looking at pixel RGB values.

The usual way this kind of work is done is with a scanning back on large format camera. I'd suggest that except (1) I've never seen one for rent, (2) A camera like that requires skills a Nikon user is not likely to have while the medium format equipment would seem familiar. (3) the scanning back i better suited to full size reproductions where the final print size is several feet


BOTOM LINE: Use profesional equipment, don't try the "wing it" with consumer sized SLRs. Get the lights "right". Use a color and grey card to get the color balance dead-on perfect.

ChrisA
Oct 30, 2008, 03:33 PM
As far as lighting, I have access to two what I consider "regular" lights (they're flashes but not strobes… studio lighting… details coming…) and two SB-800s and one SB-600.

I've heard two strobes on either side…*which I like. These paintings are very large (bigger than me); should I just scale that same solution to the larger painting?

Light is light. The key is to use all identical units with all units set to the set power level. You want the color of the light to be the same. Set them up symmetrical so the fall off from one unit is cancelled by fall off from another. Remember light falls with the square of the distance (inverse square law) so you get more even light if the lights are pulled back farther. One light on each side should be enough unless the path length from the light to the art's center is very much less then the path from light to art's corner. You can experiment at home. Set up your lights and shoot a blank white wall. (remember to dim the room lights) then check pixel values on the computer, they all should be roughly the same.

You will be using the lights in manual mode. Do NOT use any auto modes on the lights or camera. You want to be certain that your calibration shots of the color and grey cards are done exactly the same as for the real subject. Any automatic exposure will mess this up badly.

Once you switch to manual mode an expensive SB800 is not better than a Walmart "flash-o-max". Light is light.

termina3
Oct 31, 2008, 01:37 PM
Thanks for all the help guys!

I'm going to stick with my D300. No one is paying, so there's no money to rent something. I've talked to the end-client (not my client) and they want a JPEG, which to me indicates that I could probably get away with upsampling the image by ~10%.

I'll definitely take into consideration your lighting suggestions though; thanks for all of those! Super-helpful.

firestarter
Nov 3, 2008, 04:46 PM
You are going to need more pixels then you can get with a Nikon SLR. You can get those by "up scaling" the image in Photoshop but if your client knows what's up and has some experience he will be on to that trick.


I completely disagree.

Their printing process needs a 350dpi file to print at that size. In reality, your eye won't resolve more than 200dpi on a piece of paper, so up-scaling will be fine. A D300 has ample resolution for a 9.5x12 inch print.

I'd be more worried about colour - and getting that correct. Have you been told what file format or colour-space they're using? Is your monitor properly colour-profiled?

termina3
Nov 3, 2008, 05:47 PM
I'd be more worried about colour - and getting that correct. Have you been told what file format or colour-space they're using? Is your monitor properly colour-profiled?

I've already done the shoot; everything went off nicely. The paintings were quite easy to color match (roughly), and I threw in a gray card for post-processing adjustments.

Their only specifications were JPEG to be printed at the aforementioned size and DPI on a disc. This indicates to me that either they don't care about the fine details, or they don't know to care. Either way, it makes my job considerably easier.

This photography is not for a reproduction of the artwork, more for a magazine or catalog (but a coffee-table quality one).