Author Topic: Digital Darkroom (Read 8892 times)

mtnbkr · « **on:** April 17, 2009, 11:01:31 AM »

Ok, now that I have a DSLR, I need to give more consideration to a "digital darkroom". I never bothered with my previous digital cameras because that were all P&S "digitoys", but the D40 might make it worth the effort.

Currently, I've left the WB untouched until I see how the camera handles various situations (though by experimenting with it last night, I can see where I might need to change it for certain shots). I did adjust the exposure compensation to underexpose by .7 on the recommendation of Ken Rockwell. Apparently, and I saw this for myself, the D40 tends to overexpose because it sets exposure by the darkest item in the scene. I tried -.3 compensation, but that wasn't quite enough. So far, the pics are pretty close exposure-wise, but I need to shoot more to make a final determination. I had to make similar adjustments on my N80 to get the sort of exposures I wanted.

So, how much post exposure processing do you do? What tools do you use? Do you shoot RAW or just a high quality JPG (or both as I'm doing right now)?

I'm not keen on the idea of spending a lot of time tweaking each and every image. I'd prefer to get the average image right in camera and use computerized processing to tweak special or critical images.

Chris

Harold Tuttle · « **Reply #1 on:** April 17, 2009, 11:36:52 AM »

IMHO, Apple Aperture is the best toolset for imaging & project metadata management

Adobe Lightroom is another option that will run under M$ control

go_bang · « **Reply #2 on:** April 17, 2009, 11:40:12 AM »

I use the full version of Adobe Photoshop for editing and Adobe Bridge for organizing and previewing. For the cameras I have that are raw capable I shoot everything in raw mode. Back on the PC I convert the raw files to Adobe DNG, archive both in seperate folders, and only keyword and work off the DNG files. I use Adobe Camera Raw to convert the DNG's to editable files for Photoshop.

The big advantages of using the raw mode is the ability to recover blown highlights, pull detail out of the shadows, and adjust the white balance after the fact. The sensors will clip the highlights easily like slide film, but are able to capture shadow detail better than almost any film you can buy. One of the reasons Ken Rockwell, and a lot of others, suggest dialing in some amount of underexposure is to reduce the frequency of which you clip the highlights. If you haven't clipped the highlights that badly you can usually recover them while bringing up the exposure on the rest of the image in the raw converter software.

It's been my experience that most well exposed digital images need little in the way of post processing to get a presentable picture. Modern white balance systems usually get close enough to true that often only a little adjustment is needed. In the vast majority of cases I find that I only need to tweak the white balance a bit in Camera Raw, and then in Photoshop I usually need to apply a little levels and/or curves adjustment to get the image where I want it. Prior to using digital cameras I used to work with scanned film. I'm probably spending 5-10% of the time I used to spend working with scanned film in post because I don't need to spot out dust specks and scratches or bring whacked out color casts back in line because the color temperature of the scene was so far off what the film was designed for.

If you don't want to drop the coin for Photoshop go check out Photoshop Elements. It has most everything you would need for processing snapshots and such and also works with Camera Raw. If you're looking to make your own prints than I would recommend getting a decent for calibrating and profiling your monitor. Doing that helps get what you see on your screen to more closely match what will come out of your printer. If you're going to have labs make your prints or just process stuff for email and web pages you can probably get by without calibrating the monitor.

mtnbkr · « **Reply #3 on:** April 17, 2009, 11:58:08 AM »

Good info, thanks.

What about using Gimp?

I'll do the vast majority of my printing at other places. Penn Camera, where I got my camera, gave me a year's worth of free prints (10 4x6, 3 5x7, 1 8x10, and a photo CD each month), so I'll probably go with them for the time being. My printer does a decent job, but I'm not sure how much calibration flexibility I'll have with my laptop.

Chris

go_bang · « **Reply #4 on:** April 17, 2009, 12:18:23 PM »

I've never used GIMP, so I really cannot comment on it. If you're talking about GIMP under Linux there is currently no color management for Linux like there is for Windows or Mac, so if you go the display calibration route things will get complicated. GIMP under Windows might not have the same problem, but again I don't really know if GIMP for Windows will plug into Windows color management. If you're going to use raw files with the GIMP then how you do so will depend on the OS you're running. If Windows you can download Adobe's DNG Converter. This is a standalone program that will batch convert your raw files to DNG, and GIMP will work with DNG. If you're talking about GIMP under Linux you will have to search around for other tools. They're out there.

The calibration process isn't all that dependent on what external controls you have on the screen. It uses the OS color management system and driver software to adjust the default color balance and gamma settings. A basic calibration kit will include a device that sets a light sensor agains the screen and software that performs the calibation process. Colorvision's Spyder is a popular example of this:

http://spyder.datacolor.com/

But like I said, if you don't plan on printing your own very often you can skip this part. With as cheaply as you can get lab made 4x6's and 5x7's done through online outfits it's not worth printing anything smaller than 8x10 unless you need it right away. Also, as you work with your computer and printer you'll start to get feel for how what you see on the screen will print out. If you ever decide to start making inkjet prints from 11x17 or larger you will defintely want calibrate the display so you're not wasting paper and ink.

Brad Johnson · « **Reply #5 on:** April 17, 2009, 12:25:10 PM »

Photoshop Elements here. Pretty slick, plenty good for everyday use, and very user friendly. Came with the camera.

However... CALIBRATE YOUR MONITOR FIRST!!!

Before hauling off and doing anything with software or trying to compensate in-camera make sure your monitor is displaying accurately. When I first went digital I also though I was having exposure problems. Turns out the camera was doing a fine job, it was my monitor that was improperly calibrated.

Brad

mtnbkr · « **Reply #6 on:** April 17, 2009, 12:30:08 PM »

I'll check out Elements as well.

My first few photos looked overexposed in the camera's LCD. When a beige wall, illuminated by a warm light, shows up bright white on the camera's display, it's probably overexposed.

Chris

Brad Johnson · « **Reply #7 on:** April 17, 2009, 12:33:35 PM »

Not necessarily. I bet the camera has a brightness setting for the display. That may be out of whack.

It could also be the metering. Are you set for spot or evaluative? Spot metering can cause highlights to be blown out if the subject is relatively dark. It's especially bad on bright sunny days if the subject happens to be in a bit of a shadow.

Check the in-camera histogram for exposure uniformity. If that checks out, download the pics to the computer and see how they appear on-screen. Check those first and see what's going on with the image before you begin messing with compensation settings.

Brad

mtnbkr · « **Reply #8 on:** April 17, 2009, 12:42:05 PM »

Display brightness was turned down to the lowest level.

I didn't download those pics, but I did download the ones of my daughter. With exposure compensation set to -.7, the pics were fine on the laptop screen and camera LCD.

It's been my experience that Nikon cameras using matrix metering tend to overexpose a tad for my tastes. This corresponds with Ken Rockwell's reporting on this regarding the D40.

Anyway, I need to get a few more pics tonight. I didn't have much time to mess around with it yesterday.

Chris

go_bang · « **Reply #9 on:** April 17, 2009, 12:44:13 PM »

Yes, learn how to read and use the histogram. That will tell you much more about your exposure than anything you see on any screen.

Standing Wolf · « **Reply #10 on:** April 17, 2009, 10:04:43 PM »

Quote

Display brightness was turned down to the lowest level.

Unfortunately, lots of monitors these days don't let us adjust brightness and contrast separately.

go_bang, you sound like a professional.

Ron · « **Reply #11 on:** April 17, 2009, 11:45:55 PM »

Quote from: Standing Wolf on April 17, 2009, 10:04:43 PM

Unfortunately, lots of monitors these days don't let us adjust brightness and contrast separately.

go_bang, you sound like a professional.

My monitor settings are calibrated using Spyder Express 2.2

It is a program and piece of hardware that checks your monitor output and adjusts it to true color.

Getting your printer synced up is another whole different story...

mtnbkr · « **Reply #12 on:** April 18, 2009, 07:47:01 AM »

Quote from: Standing Wolf on April 17, 2009, 10:04:43 PM

Unfortunately, lots of monitors these days don't let us adjust brightness and contrast separately.

Actually, I was referring to the LCD on the back of the camera.

Anyway, there isn't much adjustment I can do to my laptop. Using one of those web based color wheel adjustment tools, my screen is pretty close to where it should be (according to those pages). I took a bunch of pictures yesterday and what I saw on my laptop matched what I was seeing while taking the pictures

I pulled up the RGB Histogram for various shots, but I have no clue how to read them, even after reading an article on the subject. I understand what they're showing, but I can't determine if one channel is too high or low just by the histogram.

Chris

mtnbkr · « **Reply #13 on:** April 18, 2009, 10:49:24 AM »

Ok, these pics looked perfect on the screen, but are a bit dark when printed (about one stop). I frequently have this problem from a variety of sources (other digital cameras, scanned prints, etc), so I think it's the printer, but I wanted to get more opinions. Check them out and let me know how they look exposure-wise on your computers. I've made no adjustments to the pictures either during or post exposure. White balance was set to Auto, exposure compensation was -.7. ISO should be 200 on all three.

The JPG files are the "Large, Basic" JPGs captured when using "RAW+JPG".

They're full size, so I'm not going to "inline" them into the thread. Dialup users would hate me. :)

Amtrak Commuter train at 6:30pm: http://mysite.verizon.net/allencb/DSC_0004.JPG
Cherry blossoms in our front yard at 6:45pm: http://mysite.verizon.net/allencb/DSC_0007.JPG
Abby with an attitude (pic taken in medium shade a minute or two before the Cherry Blossom pic): http://mysite.verizon.net/allencb/DSC_0009.JPG

THanks,
Chris

Brad Johnson · « **Reply #14 on:** April 18, 2009, 11:52:30 AM »

They look about a half-stop dark on my monitor.

LCD displays are notirious for causing images to appear "hot". Even though you don't have a lot of user-level control over the settings some of the monitor calibration tools do it at the display card.

Brad

mtnbkr · « **Reply #15 on:** April 18, 2009, 12:43:08 PM »

Ok. Half a stop isn't much. I did take some more test pictures with different exposure compensation settings and sent them to walmart to see how they print there.

Chris

Brad Johnson · « **Reply #16 on:** April 18, 2009, 01:31:04 PM »

Don't be surprised if they come backing looking ok. Most digital printing services will have some kind of auto-exposure correction built in. I've had several shots that I had intended to be light/dark but came out looking normal when printed commercially.

Walmart seems to do an ok job. I've had more consistent luck with Walgreens, though.

Brad

mtnbkr · « **Reply #17 on:** April 18, 2009, 03:19:52 PM »

Yeah, the prints came out fine. The techs at WM don't make any adjustments, but I forgot about the auto exposure in the printing machine. I'll take a couple to Penn Camera, I imagine they can print the file exactly as delivered.

We don't have any Walgreens around here that I'm aware of.

Chris

mtnbkr · « **Reply #18 on:** April 18, 2009, 08:08:25 PM »

Epiphany time.

It occurred to me as I read the umpteenth article on screen and printer calibration that I'm wasting my time. Except for the odd print here and there, I am not going to be printing at home. I can upload to Walmart and have Fuji Crystal prints in an hour for $0.18 each (cheaper than I can print at home). I can do something similar with Penn Camera (my local camera shop). The pics I take and view on my camera's LCD look the same on my laptop LCD, which look the same as printed at WM. I need to get an honest, uncorrected print so I can get a better idea of what my camera is actually doing, but the results so far are pleasing. I do need to remember to change WB settings for a given scene. "Auto WB" doesn't quite cut it based on my limited experimentation (tends to be too "cool").

Chris

Bogie · « **Reply #19 on:** April 18, 2009, 08:16:55 PM »

One consideration: Will that camera shoot in RAW format? I dismember what Nikon calls it. Makes for bloody huge images, but when I was using Nikon Capture to grab and catalog them, I could go up/down two stops with very little weirdness.

If you can shoot in RAW, do it. Don't compress a damn thing any more than you have to. That way, when you ask me to blow something up to 24x36 (or larger...), you won't be disappointed.

bogie@meramecdigital.com

Gowen · « **Reply #20 on:** April 18, 2009, 08:22:42 PM »

My wife just got a free DL of Corel, I was very impressed. Sure, it's not Adobe, but it was very good software.

mtnbkr · « **Reply #21 on:** April 18, 2009, 08:45:04 PM »

Quote from: Bogie on April 18, 2009, 08:16:55 PM

One consideration: Will that camera shoot in RAW format? I dismember what Nikon calls it. Makes for bloody huge images, but when I was using Nikon Capture to grab and catalog them, I could go up/down two stops with very little weirdness.

If you can shoot in RAW, do it. Don't compress a damn thing any more than you have to. That way, when you ask me to blow something up to 24x36 (or larger...), you won't be disappointed.

bogie@meramecdigital.com

It does shoot RAW (NEF in Nikon terminology). It'll even do RAW+JPG Basic, which is what I'm currently doing. The images linked above are the "Basic JPG" files it creates. I'll probably stick with RAW+JPG until I determine how much, if any, post exposure manipulation I'll be doing. With a 4gig card, space isn't exactly at a premium yet (I can get 477 shots at RAW+JPG).

Chris

go_bang · « **Reply #22 on:** April 18, 2009, 09:18:44 PM »

I kind of figured display calibration wouldn't be worth your time, given the reason you bought the camera.

Here's how to read a histogram in simple terms:

Think of the histogram as a chart. The horizontal access represents exposure. The far left is zero, for compete black, and the far right is 255, for complete white. The vertical axis represents pixel count. The higher the line at a given horizontal value, the more pixels in the image have an exposure rating at that value. For a black and white image you only have one histogram. For color images your actually have four. One for red, one for green, one for blue, and one that is a mashup of all three. If your camera or image software only shows you one histogram for a color image then it's the last one I mentioned.

So, what does it all mean? If the vertical lines on your histogram slope up from zero, have nice peaks and valleys, and slope back down to 255 then you probably have a well exposed image. Than means that nothing in the image has been rendered completely black, thus losing shadow detail, and nothing has been rendered completely white, thus losing highlight detail (aka blown highlights). If the veritcal lines on the histogram are bunched up at the left side of the graph then your image is under exposed. If they are bunched up at the right end, your image is over exposed. Ideally, you want the first condition I mentioned. Nothing's perfect, so you'll always be settling for a compromise.

In practice, with a DSLR you are better off under exposing and pulling the exposure up in post because DSLR sensors are extremely good at preserving shadow detail, but absolutely awful at preserving highlights (actually all image sensors stink at preserving highlights, but the big one's in DSLR stink at it less than the small ones in compact digicams). This is where raw comes into play because then you're playing with ALL the data the sensor has to offer. Anywhere from 12-14 bits per pixel. JPG data is only 8 bits per pixel. Much more data to work with in the raw file, which is why you can do what you can with them.

go_bang · « **Reply #23 on:** April 18, 2009, 09:22:01 PM »

Quote from: Brad Johnson on April 18, 2009, 01:31:04 PM

Don't be surprised if they come backing looking ok. Most digital printing services will have some kind of auto-exposure correction built in. I've had several shots that I had intended to be light/dark but came out looking normal when printed commercially.

Walmart seems to do an ok job. I've had more consistent luck with Walgreens, though.

Brad

Same experience here with York Photo Labs. I uploaded a bunch of images to their site that were straight out of my Canon S400 compact and ordered a set of prints of them. The prints can back almost drop dead perfect.

mtnbkr · « **Reply #24 on:** April 18, 2009, 09:25:23 PM »

Go_bang, thanks for the explanation, it made a lot more sense that what I've read before.

Chris

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Author Topic: Digital Darkroom (Read 8892 times)