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Beyond Megapixels Part III
 
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Joe
Kurtis

Jun. 14, 2004
If you haven't already, make sure to check out Part I and Part II.

Introduction

This last installment of Beyond Megapixels contains an overview of camera function, such as metering, white balance and focusing systems, popular filetypes and their usefulness to the photographer, and features that define each digital camera. In keeping with the editorial nature of this series, I will share my preferences and opinions of these aspects when I deem prudent.

Function

The average photographer will be relying on the automatic systems of the camera to provide the correct focus, metering and white balance when taking a picture. In difficult or tricky shooting situations, the photographer may choose to manually adjust these settings. Before delving into the specifics of these variables, it is important to first make certain that a camera has the ability to manually control these settings. When you are first purchasing your shiny new camera, you may not think that you'll ever venture beyond the automatic settings of the camera, but as you become more and more addicted to digital photography there is a great chance that you'll find yourself wanting more control over the shot. That said, let us move on to focusing systems!

There are two major factors that characterize a good focusing system: speed and accuracy. It is difficult to test this when shopping for a camera as you are, at best, limited to the lighting situation in the store you are browsing at. A true test of a focusing system is in low-light, low-contrast environments. The Sony has a unique advantage in darkness with its utilization of a laser pattern "holographic" focusing system. The ability to choose a focus point within your viewfinder can assist you in focusing exactly where you want. The Minolta A2, for example, has five focus points to choose from, and the Canon Digital Rebel has seven. Particularly in situations where you will only have a shallow depth-of-field, focusing on the right spot is imperative, or you lose the shot.


Selectable focus points help place the focus right where you want it.


The metering system of a camera determines the correct exposure when shooting in aperture priority, shutter priority, program and automatic modes. Even in manual mode, the metering system will tell you when your exposure is correct. The latest cameras sample from up to and over 1000 points of a scene and set the exposure accordingly. Various metering modes will change how much "weight" is given to an area of the scene. Center-weighted metering will factor the center of the scene more than the edges when metering the scene. To visualize exactly why this is important, envision a man in a black tuxedo with a snowy mountain-side in the background. If you expose for the bright white of the snow, you will lose the tuxedo into a deep, dark black pit. On the other hand, if you expose only for the black tux, the snow is likely to blow out completely. Okay, so maybe you won't have to deal with the tux on a mountain-side, but a wedding dress is just as bad.


High contrasts of dark and light colors can be difficult for cameras to automatically meter.


You may have noticed that sometimes when shooting under fluorescent lights, your pictures come out very yellow. This is caused by poor automatic white balance. Digital cameras must adjust for the color temperature of lights when processing an image. Incandescent lighting casts a warm glow throughout a scene, and the camera adjusts colors accordingly so that everything is not affected by the color of the lighting, meaning that a white wall will appear white in the final image if white balance is done correctly. The ability to manually set a white balance is very useful when shooting in difficult lighting situations, such as a mixed light environment with both fluorescent and incandescent light sources. Before taking the shot, you can shoot a frame of something white or grey (there are tint-free cards made specifically for this purpose), and the camera will use that info to process images correctly. Just remember that a custom white balance is only good while shooting in the same lighting environment, if it changes, you need a new white balance. In general though, the automatic and preset white balances available in the latest prosumer and DSLR cameras are adequate.


Mixed lighting can cause unpleasant color casts.


 
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Page 1: Introduction & Function
Page 2: Filetypes
Page 3: Features & Conclusion

23 User Comments
1 - Posted by Guest on June 16, 2004 - 9:39 am

You don't need special hardware to do panoramas. Software such as Panotools and Hugin will help you join sequential images.

Any panorama taken without the axis of rotation carefully aligned with the lens's nodal point may look slightly unusual. This is especially true of panoramic VR animations. No amount of software or in-camera trickery can correct for this.

2 - Posted by Guest on June 16, 2004 - 10:24 am

The article is part 3 in a series, but has no links to the first two parts, at least none that are easily and clearly visible.


3 - Posted by Guest on June 16, 2004 - 10:49 am

This has been an interesting and informative set of articles. Obviously, however, the author has a genuine predilection for Canon, Minolta, and a few select other manufacturers. The author, in this latest installment, completely (and one has to assume voluntarily and knowingly) bypassed the additional information and usability of Nikon's NEF file format, and has basically side-stepped Nikon en totem, except for the off-hand mention of Nikon's lowest-priced DSLR, the D70. As well-written as the articles have been, this intentional ignorance towards the one company who is significantly innovating in both hardware and software development in the digital imaging industry, and the one company who is advancing lens technologies specifically for digital platforms, is egregiously misleading.

4 - Posted by joebok on June 16, 2004 - 10:56 am

A very nice set or articles - thanks! I recently sold off a Sony F808 and bought a Nikon D70. There were two very big differences that I experienced which you didn't really touch on - focus and speed.

I have found it to be nearly impossible to manually focus a prosumer type camera - the LCD is just not capable of showing enough detail to focus on something like a spider web. This problem goes away with the SLR where you are actually seeing the subject optically.

Maybe the newer prosumer cameras are faster, but ever since I switched to digital the hardest thing I've had to adjust to is the slowness. Turning the camera on, splash screeh, waiting for it to focus, calculate white balance and exposure; then you can take the shot, then waiting for it to be written to the card. The Nikon does not have this problem. It is instantly on and will take 7 or so max-quality jpgs without slowing. If you have a fast enough card you will hardly notice the slowdown when the buffer fills.

One last thing that I've noticed between the SLR and prosumer - the setup. With the Nikon I have a lot more control over the behavior of the camera. For example, I can tell it at what shutter speed to change ISO settings at if I don't like the default. Also, I can control the behavior of some of the buttons on the body - to make it work exactly how I want it to.

No question I'm a fan of the SLR, and the Nikon D70 specifically. Going back to the bigger size camera actually feels very comfortable to me. None of the 8 megapixel prosumers are what I would call "pocket" cameras anyway so the size difference is not a factor for me.

Anyway, thanks again for the articles!

Joe

5 - Posted by Joe on June 16, 2004 - 11:41 am

The Nikon NEF is simply the specific name given to the raw format by Nikon. Fuji, Canon, Minolta and Olympus all have their own as well. Rather than list all specific file extension, the term RAW is used in the article.
As per bias toward Canon and Minolta, that is simply not the case. I'm sorry if you feel I should have sang more praises for the 8700. The D70 is a great camera, and if I were buying, I'd choose it before the Digital Rebel any day. Minolta did go the extra mile in providing the A2 with features not found in the cameras of any other brand. They should be praised for that...
Olympus seems to be advancing lenses for digital platforms as well, don't you think?

6 - Posted by Guest on June 16, 2004 - 12:23 pm

I appreciate your response, Joe. Thanks for that.

You said: "Nikon NEF is simply the specific name given to the raw format by Nikon." True, but untrue. The NEF format is far superior to Canon's RAW format in gamut, scalability, and resolution, thanks largely to Nikon's superior CCD (at least on the D100). I own two D100s and one Rebel, and hands-down, even on side-by-side shoots, the quality of the NEF is vastly superior to the RAW. I can take my NEF's and TIFF them to 36"x48" (pShop bicubic after the Nikon Editor upsize) without noticable degredation. I'm lucky if I can tweak my Canon RAW files to 24"x36" without pixelation resulting from the RAW file itself -- Canon just doesn't leave me enough data for pShop to upsize as far as I can my NEFs. To get my RAWs that big, I wind up spending 3-4 times the amount of post-processing time my NEFs take me.

Indeed, several players in the industry are innovating, but as your series has stated, there are things beyond the 'megapixelisms' to consider, and the most fundamental is actually lens quality. Olympus is 'advancing lenses for digital platforms' but not in terms of glass quality, wide-format (77mm) lenses, shock resistance, and several other 'little things'. Sorry, I don't buy their marketing material out of hand, and I don't have the personal industry contacts that folks like you enjoy, so as to preview and review products before they hit the market -- so grain-of-salt me on that one.

Yes, I'm admittedly a Nikon geek, but I don't think you should have sung praises for any particular camera. There are several great ones on the market for 'pro-sumers' (eek what an oxymoron!) and enthusiats. Meanwhile, virtually all the manufacturers are ignoring the needs and desires of professionals, but that's another issue entirely.

As a professional digital photographer (some nine years under my belt with digital), I thank you for your insights in this series. Truly, there is far more than the megapixelisms to consider, and since your article is written to the consumer audience, please allow me to retract my obviously-biased assertions, and please accept my thanks for educating the enthusiast marketplace.

7 - Posted by Joe on June 16, 2004 - 12:53 pm

Guest, thank you again for commenting. I too work in the professional realm of digital photography. Specifically I work with images directly from the camera. We shoot with 2 D100's at my place of work and I am quite familiar with thier good features, as well as thier shortcomings.
I have also worked professionally with the raw files produced by cameras from Nikon, Kodak, Minolta, Fuji and Canon. It is my observation that the files are more similar than different. Obviously, the info has to be there from capture, which is where I see the biggest difference in quality.
I believe in giving credit where credit is due, and think I have done so without giving undo amounts of praise to any single manufacturer. Out of the DSLR's I have shot with, my all time favorite have been the Canon D30, which was definately ahead of the pack in price/performance, and the current S2 that I shoot with. These cameras too have shortcomings.
I have a problem when people contact me in response to these articles and tell me I am so very wrong because "Brand X is the best at this, this and this and all other manufacturers suck." I really have no response to that other than that you are missing out on great cameras because of your blind brand loyalty.
Nikon fans v. Canon fans are worse than ATI fans v. Nvidia fans.

8 - Posted by Guest on June 16, 2004 - 12:55 pm

As far as panoramas are concerned, it should be noted that many of the HP cameras such as the R707 can do this in the on-camera software!

9 - Posted by Kurtis on June 16, 2004 - 2:14 pm

"The article is part 3 in a series, but has no links to the first two parts, at least none that are easily and clearly visible."

If you click on articles on the left side of the page, all our articles will come up, and the other 2 Beyond Megapixels articles are easy to find. However, I'll go and edit the articles so they link to eachother.

10 - Posted by Kurtis on June 16, 2004 - 2:27 pm

Okay, articles have now been edited so that they link to eachother. In Part I, at the end now there is a link to Part II. In Part II, in the beginning there is a link to Part I and at the end a link to Part III. In Part III, in the beginning there are links to Part I and Part II. =)

11 - Posted by Guest on June 16, 2004 - 6:23 pm

I have a two-and-a-half year old boy. So my camera need is all about *speed*. So I wish that the series had discussed this 'beyond Mpixel' issue. The long delay on my Canon S110 makes it virtually unusable for photographing my son. I am considering switching back to film, because I have heard that there's nothing faster without going to a much bigger DSLR camera. Any thoughts?

12 - Posted by Kurtis on June 16, 2004 - 7:21 pm

When it comes to speed, I don't think there really are any digital cams out there besides the extremely expensive DSLR ones, that would be able to instantly focus and take a shot without a delay. Unfortunately that isn't much of a variable at the moment with digital cameras, none of the non-DSLR cameras have the sort of speed needed for instant shots like that, as far as I'm aware of...

13 - Posted by kb244 on June 16, 2004 - 9:13 pm

Most consumer digital cameras use an active Autofocus system, that either emits an infared beam ( or laser like some new ones focusing almost in complete darkness ), which can take time. Most Digital SLRs including ones such as the Canon Digital Rebel, and The Nikon D70, use passive Autofocus, where the AF system pushes the lens' focus motor back and forth until the picture becomes clear, so the autofocus on an SLR is much faster, depending on how fas the AF Motor is (such as Canon USM [ Ultra Sonic Motor ] being the fastest of the canon line. ) , if speed is your thing ( and I've owned a S110 so I feel your pain ) , an SLR is really your best option, if you do not want to ahve to pre-focus. Another method if you upgrade to a camera that allows manual settings of the shutter and aperture, is using hyperfocal, this allows you to set things in a fix focal range, so everything from say 2 feet to 100 feet are in some degree of focus, many film cameras under 50$ use this kind of fixed focus system.

14 - Posted by kb244 on June 16, 2004 - 9:18 pm

By the way, if you have the dough to spend, but are not comfortable with the SLR area of cameras. Minolta did release a DiMage Z2 thats supposed to be "Virtualy" instant autofocus for any situation. Keep in mind with alot of non-SLR digital cameras, there are trade-offs for the big features, same is true with DSLR but not always to such a great extent.

15 - Posted by Guest on June 17, 2004 - 7:28 pm

an excellent series of articles.
in your buyer's guide I would love to see recommendations for cameras that fit in your pocket but with the best possible picture--thank you, rik

16 - Posted by Guest on June 17, 2004 - 9:34 pm

Several of of over at nikonians.org are very curious about the "virtual fill flash" feature of the Nikon D70 mentioned in the 4th paragraph from the bottom of page 3 of this article.

Where is this feature controlled and where can we find more information about it? It does not appear in the manual. Is this a reference to custom curves, or do you really know about an on/off feature for the D70 that operates as you describe?

I'd love to know more! Thanks! -James

17 - Posted by kb244 on June 18, 2004 - 1:38 am

The Virtual Fill Flash, is pretty similar to what HP came out with on their cameras several months ago, almost last year I think, basically photoshopping on the fly almost. In my opinion, I try to avoid any kind of camera that does more to the picture than basic color correction.

18 - Posted by Guest on June 18, 2004 - 5:10 am

I'm not trying to discuss any merit or pros/cons to a virtual fill flash feature, I simply want to know if the author knows something I don't. I own a D70 and as far as I know that entire paragraph is false and the D70 has no such feature. I'm hoping he will respond and clarify this for me by explaining how to access this feature so that I might learn something new about my camera, or provide an explanation/correction if he was mistakenly referring to another feature or camera.

19 - Posted by kb244 on June 18, 2004 - 5:02 pm

Well you may be right about that, I'm not entirely familiar with the D70 myself, but I did not see such features on other review sites of the D70. The other thing is, I do not normally know of Digital SLR cameras using features like that, usally they try to keep the shot raw as possible, only changes are actual flash exposures, iso, color balance, color map range. (hint author , add a reply ) Also according to nikon's website it doesnt have any digital flash, its got a bunch of flash exposure compensation modes and such, which is still actual flash, and not done digitally.

20 - Posted by Kurtis on June 19, 2004 - 1:06 am

Joe's out of town right now, so he isn't available to ask about your D70 fill-flash feature. I'll let him know to reply when he gets back though.

21 - Posted by Guest on July 11, 2004 - 10:21 pm

I'm still curious about what Joe knows that the rest of us don't about an in-camera virtual fill flash feature on the D70. Thanks! -James

22 - Posted by Guest on August 20, 2005 - 12:38 pm

I know this set of articles are dated but a couple of points. The use of 35mm lenses for the sensors in DSLRs goes far byond investment in existing lenses. The promise of a full frame DSLR with larger sensors has been discussed in a tangible way even in the kingdoms of Nikon and Canon. It is only a matter of time. Then we will all be glad we didn't abandon the glass.

Also, JPEG and lossy file formats are to be avoided at all costs. Even the amateur who uses a point and shoot pocket camera can see the effects of what they are doing. Take a JPEG, open it in your photo editing package and alter some characteristics of the image, brightness, contrast, color, etc. Save the file. Close the file. Now go back and open the file and repeat this procedure 3 more times. Now go and print a modest 5x7 reproduction of this file. You will be shocked and troubled. Every time you save the JPEG the image is re-compressed and image losses are multiplied. People changing from 35mm point and shoot probably aren't aware that if you aren't careful, you have no preserved digital file where image quality is maintained.

The solution is to step up to one of the many Camera RAW format and maintain that file or a converted lossless file such as the Adobe Digital Negative standard (.DNG)as your archive. Then you can save as a .JPG if you wish to photoprocess via internet at your corner drugstore.

I exclusively use Nikon digital SLRs and the Nikon NEF format. But the low end of the market is shooting photos of kids growning up, weddings, vacations, etc. and haven't been properly warned about the dangers of keeping your precious memories in a lossy file format that degrades with every modification. I know the files are smaller with .JPG, but not having a digital negative is just plain stupid. Memory cards are too cheap now days to risk your memories.

Doug

23 - Posted by Kurtis on August 21, 2005 - 3:27 am

Interesting comments you've made Doug. Thanks for the feedback. =)

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