The Canon EOS 10D Digital SLR:
Impressions and techniques Part 3
by Norman Koren

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Part 1 | Introduction | News | The EOS-20D | Links  | Why I chose the 10D | Lenses | Accessories
Part 2 | Read the manual! | Menu | Operating modes | Settings | Tips
Part 3 | Image quality/file formats | Nikon D100 comparison | RAW conversion | Flash
Part 4 | Resolution compared to 35mm | Dynamic range and tonal response | Summary

Related pages: Digital cameras | Digital vs. film | Tonal quality and dynamic range in digital cameras
In Part 1 we introduced the EOS 10D and covered many of its operating modes.

In this part we continue in this part with a description of storage formats, a comparison with the Nikon D100, descriptions of Raw conversion programs, and flash operation.

In Part 3 we discuss resolution and image quality and present conclusions.

A number of EOS 10D images are now on my Image Gallery 2003.

Image recording quality/file formats

You can choose between six JPEG formats and RAW (.CRW; Creative modes only). JPEGs are defined by size: Large (3072x2048 pixels), Medium (2048x1360 pixels), and Small (1536x1024 pixels), and by quality level: Fine (very little JPEG compression loss; no artifacts), and Normal (some JPEG loss, slight artifacts). JPEG sizes range from about 2.4 MB (Large/Fine) to 0.4 MB (Small/Normal). Fine JPEGs are about twice the size of Normal. The exact size varies, depending on amount of image detail. RAW files contain original Bayer sensor data (RGRG and BGBG in alternate rows) with minimal processing. Size is around 6 MB with a modest amount of lossless compression.

I use JPEG Large/Fine for casual shooting and RAW whenever I'm serious about image quality. A JPEG image is embedded in RAW files. You can choose the size/quality level, but I see no reason to change it from its default of Small/Normal.

Why choose RAW? Because the sensor captures data with 12-bit precision. It gets truncated to 8-bits when a JPEG file is written. This doesn't really hurt if the White Balance, Contrast, and Color Saturation are set properly and the image needs little editing. But image quality can suffer if much editing is required. For ultimate quality it's best to edit in 48-bit color. RAW files can be saved as 48-bit color TIFF files (with 16-bit depth).

The Nikon D100 vs. the Canon EOS 10D

Here are some comments from my friend Dennis Wilkins-- a passionate photographer and busy quality control consultant who recently took early retirement from HP. He pays attention to detail. The EOS 10D got a lot of media buzz when it was announced in March 2003 for $1499. Nikon promptly dropped the price of its D100 to $1699-- competitive, but it hasn't quite gotten the same buzz. The bottom line is that the two cameras differ in numerous details but overall image quality is comparable. If you have Nikon lenses, get the Nikon. D100 comparisons: Ken Rockwell's D100/10D comparison | Clint Thayer (  D100 links: Ken Rockwell | Thom Hogan || | | Sony ICX413AQ CCD image sensor
Nikon provides one-stop higher ISO speeds: it has 6,400 but lacks 100. Canon supposedly has slightly lower noise than the Nikon, but the tests I've seen show no visible difference. Both cameras are nearly noiseless to ISO 800, especially compared to film.

Nikon RAW files and software are considered to be excellent (and I would agree). There are two RAW (NEF) formats: uncompressed (9 MB file size) and 2:1 losslessly compressed (4.5 MB file size), only 50% larger than JPEG. For serious work the advantages of RAW files far outweigh the extra storage available with JPEG. Canon's RAW files have a quasi-compressed RAW mode yielding about 6.5 MB files. The Nikon can write over 210 RAW images per GB versus about 155 for the Canon.

Nikon Capture software is not included with the D100, but is well worth the ~$100 cost for anyone serious about photography. Nikon Capture provides complete post-processing while leaving the original RAW information intact (by tagging any correction factors) and enables conversion to JPEG and 8/16 bit TIFF files with embedded color space information. (Canon software is free; it supports 8/16 bit TIFF files and JPEG, but it's clunky. There are several alternatives. Capture One DSLR LE ($99) is outstanding. –NLK)

The Canon 10D doesn't support Write Acceleration (WA) Compact Flash cards, and is slower writing images than the Nikon. The D100 writes JPEGs 38% faster. For RAW files the difference is smaller: since an uncompressed Nikon NEF file is about 38% larger than the Canon RAW file (9 MB vrs 6.5 MB), the D100 writes them about 19% faster. On the other hand, a compressed Nikon NEF file (4.5 MB) is about 30% smaller than a Canon RAW file, enabling over 210 RAW images per GB versus the Canon's 155 images. The trade-off is speed. Nikon compressed RAW files take about 30 seconds to write (lossless compression processing takes the time) -- not good for fast-action sports but fine for scenics.

Both Canon and Nikon have shutter speeds of 30 seconds to 1/4000 with 3 fps max. The Nikon D100  has several flexible flash modes including Red-Eye, Slow Red-Eye, Slow, Front and Rear Curtain; Canon has only on/off and Red-Eye. With the Nikon these modes are available with both the on-camera TTL flash or one of Nikon’s external TTL controlled flash units. Nikon flash synch is 1/180 sec while Canon’s is slightly higher at 1/200, and high-speed (FP) sync is available with 420EX and 550EX. You can use several wireless flashes with both cameras. Slow-speed Sync is available for exposing both the subject and background in dim light. It is set automatically in the Av mode.

The Canon has 2 EV exposure compensation; Nikon has 5 EV which can be handy when making multiple exposures of exceptionally contrasty scenes to be combined digitally. (See this example. --NLK) Both the Nikon and Canon have independent settings for flash and ambient light.

Nikon battery is 1400 mAhr (and seems to last forever), while Canon's is 1100 mAhr (not sure how many shots it can make). Nikon has optional base for dual batteries (or alternately, using AA cells) that provides voice recording and digital remote interface. (Canon’s DIGIC processor and CMOS sensor are extremely energy efficient; batteries are quite long-lasting. --NLK)

The Canon takes about 3 seconds to "warm up" from the off-state -- Nikon is ready to fire within a millisecond. I find this indispensable -- and just like a "real" SLR. A significant advantage! (Agreed! --NLK)

The Canon can buffer 9 shots while the Nikon is supposedly limited to 6, but the high write speed of the Nikon enables it to shoot 8 shots in a burst at 3 fps (the first two images are written by the time it gets to shots 7 & 8). The Nikon can fire off 25 shots in 30 seconds; the Canon can shoot about 16 shots in 30 seconds.

The Nikon self-timer has delays of 2, 5, 10, or 20 seconds; Canon's delay is only 10 seconds, unless the mirror lock-up is enabled, in which case there is a 2 second delay. The Nikon's mirror lock-up and self-timer are independent. The D100 uses an excellent "anti-shock" mirror mode in place of a manual lock-up. When you press the shutter release it locks the mirror then trips the shutter after a short delay -- I really like it for field work. (With the Canon you have to press the shutter twice, unless you enable the self-timer, which has an awkward 2 second delay-- longer than needed to damp vibration but too short to get yourself in the picture. Nikon’s anti-shock mode is very nice. --NLK) 

The Canon 10D requires a $50 RS-80N3 "Remote Switch" -- Nikon uses a good old standard threaded release (I’m using my 35 year old Zeiss release). (Unlike the traditional mechanical cable release, the "Remote Switch" operates electrically. It's more flexible and less susceptible to damage from bending and kinking. The Zeiss release must have been exceptionally well made, unlike the cheapies you find on today's camera store shelves. --NLK)

Canon's in-camera viewer has a significant limitation -- you cannot view an image on the Canon until the entire buffer is written to the card. The Nikon images are ready to view almost instantly, even while compressed NEF files are being written. In addition, the Nikon viewer provides a full LCD-size view of the image whenever the image is viewed. For example, viewing a histogram is accomplished by overlaying the histogram on the image and the “blocked-highlight” view shows a full LCD-size image with blinking highlights. The Canon viewer shrinks the image to less than linear dimensions, less than the area of an LCD-size image when showing histograms and highlights. 

Canon has a 1.6 x image size multiplier, Nikon is 1.5 -- I'd rather have it closer to 1! Of course there's always the Canon 11 MP EOS-1Ds! We'll see what Nikon has in the near future.

Raw conversion

Images in digital camera sensors have "Raw" formats (.CRW files in Canon cameras) that don't conform to standard image file formats. They have the (RGRGRG..., GBGBGB...) structure of the Bayer pattern sensor and must be converted to a standard format (JPEG, TIFF, etc.) to be useable-- to be edited in standard image editors. The highly technical paper, Reconstruction of Color Images from CCD Arrays, D. D. Muresan, Steve Luke, and T. W. Parks of the Cornell University DSP Lab, which has published several papers on image interpolation, illustrates the importance of the Bayer pattern interpolation algorithm, i.e., Raw conversion. They show that the best algorithms are iterative-- far too computationally intensive for a camera, but practical on a personal computer. Although manufacturers of Raw conversion software rarely discuss algorithms (they're strictly for math geeks), this is one good reason to save Raw files and convert later.

Another reason is that several image parameters set in the camera-- White Balance, Contrast, Color Saturation, Color tone, and Sharpness-- aren't actually applied until conversion takes place. They are recorded with the RAW file, and they become the default values for the conversion, but you can change them and preview the results before the final conversion. If aren't just right when you convert to JPEG in the camera, image quality may suffer. This is particularly true of White Balance.

One more reason to use Raw images is they have 12 bits of precision (36 bits total for a color image). In-camera conversion stores 24-bit files-- 8 bits per color. You lose 4 bits. This makes little difference when the exposure is right on. But I often underexpose to avoid burning out highlights, then lighten the image in my editing program. There is a danger of "banding"-- losing tonal levels, when you do this with a 24-bit file. Raw storage allows you to convert to a 48-bit file-- 16 bits per color. You can manipulate the image in 48-bits while maintaining the highest tonal quality.

Four conversion programs are currently available for the 10D. I'll eventually get around to comparing them, but a number of reviews are available. Steve Hoffman compared several.


The built-in flash works well; it's particularly nice for filling in shadows when photographing people on sunny days. I purchased a real flash, the 420EX, but I don't use it a lot. I'm not a "serious" flash user.

Here is a casual snapshot of Hal Gould, the 80+ year old proprietor of the Camera Obscura Gallery in Denver, taken with the 24-85 mm f/3.5-4.5 comsumer-grade lens set to 44 mm. I've edited it a bit-- burned highlights, etc. I was working hastily, and I absent-mindedly left the camera at settings I used earlier outdoors: Aperture Priority AE, Aperture: f/11, Shutter speed: 1/10 (whoops!). F/5.6 or 8 would have been better. But the image came out nicely anyway. Not as good as with a professional lighting setup, but as better than you might expect from a simple pop-up flash.

Canon France has a page on using flash, in English.

Full image, reduced
Full size crop
Part 1 | Introduction | News | The EOS-20D | Links  | Why I chose the 10D | Lenses | Accessories
Part 2 | Read the manual! | Menu | Operating modes | Settings | Tips
Part 3 | Image quality/file formats | Nikon D100 comparison | RAW conversion | Flash
Part 4 | Resolution compared to 35mm | Dynamic range and tonal response | Summary

Related pages: Digital cameras | Digital vs. film | Tonal quality and dynamic range in digital cameras


Images and text copyright (C) 2000-2013 by Norman Koren. Norman Koren lives in Boulder, Colorado, where he worked in developing magnetic recording technology for high capacity data storage systems until 2001. Since 2003 most of his time has been devoted to the development of Imatest. He has been involved with photography since 1964.