Photography and Camera Blog

Black and White Conversion of Flower

2006-01-15T19:10:00.000-08:00

Still putting together a post on general black and white conversion techniques... there are a lot of different ways to go about it!

In the meantime, a couple people have asked how the final black and white version of the flowers in the Black and White Conversion 101 post was created - it was actually really simple and fast. No doubt somebody else could come along with some different way of converting it that would render a better result, but this is pretty good for a 30 second job I think, and really that conversion was just to illustrate the point of the article anyway.

OK, open the original colored image (in RGB) - take a look at each channel and look at the tonal range that it occupies.

The red channel basically sucks as a conversion source - there is so much red in each of these flowers that there is essentially no tonal differentiation between the three, and very little detail overall.

The green channel looks pretty good, but the three flowers are still tonally a bit close together. This channel at least has some merit though.

For the purposes of the previous post, the blue channel looks great for the two flowers on the right, but the left flower is far too dark.

Still, the blue channel looks pretty good as a starting point... it looks like if we were take the two flowers on the right from the blue channel and the flower on the left from the green channel, that might provide pretty good tonal differentiation between the three.

So, given these channels as a starting point, this conversion was really just a two-step job:

1) Copy the blue channel to a new grayscale document, on the theory that two out of three ain't bad.

2) Put the green channel on the layer above, toss in a mild curve to enhance the contrast in the leftmost flower just a little bit, and tweak the blending options appropriately to pick up only the midtones from the layer.

And there you have it. Other than playing around with the blending sliders, it takes longer to describe than it does to execute.

There are a LOT of different ways to create a black and white image - this was kind of quick and dirty and yet obviously gave a result far better than a straight grayscale conversion - no contest.

This was also a very easy image, set up specifically to illustrate the point in the previous post - most real-world images are not nearly so conveniently defined within the channels, so usually there are more steps involved in a good conversion, typically with a good bit of channel blending ahead of time to establish the tonal differences that you want in the overall color image prior to the conversion.

But that is for next post...

Black and White Conversion 101

2005-12-30T00:34:00.000-08:00

Happy holidays everybody! Just a short one today so I can get back to leftovers ;-)

The latest generation of inkjets are amazingly good at making incredibly rich and neutral black and white prints that rival traditional black and white film prints, and the subject of how best to convert pictures to black and white is a popular one and only getting moreso. There are tutorials all over the net with different conversion methods, most of which work at least reasonably well for some images, but what seems to be missing from most of them is a discussion of what you are actually trying to achieve. The authors seem to either assume that you already know what the critical factors are in creating a good black and white image, or, worse, they simply give a list of steps as a sort of recipe to follow, which guarantees good results for some images and not-so-good results for others.

With the power and flexibility of the digital darkroom, once you understand the factors that a successful black and white conversion needs to take into account you have available to you conversion processes and techniques that were traditionally very hard if not impossible to achieve. You can take advantage of the collective knowledge and best practices of both the prepress and traditional film photography industries as well as a large number of new techniques developed exclusively in the digital darkroom, and you can relatively easily achieve outstanding results using techniques that would have taken a traditional printmaker years to master.

So what are the factors of a successful black and white conversion?

There is really just one key concept to get your head around: you have to map detail contained in color (hue and saturation) contrast into luminosity (brightness) contrast - that is, if you want to see that detail in the resulting black and white picture!

This is the absolutely central conceptual point in achieving a good black and white conversion, so stick with this if you didn't get that last statement. If you already know color theory this next bit will be quick.

In a color picture, each pixel has a color, and a color is made up of a hue, which is a particular point in the visible color spectrum, a saturation, which very loosely can be thought of as the purity or intensity of the color, and a brightness level, which is self-explanatory. An intense orange, for instance, would have a hue in the orange part of the color spectrum (in between red and yellow) and would be both very bright and very saturated. A neon green might also be very bright and very saturated, but would have a different hue in a different, cooler part of the color spectrum (in between blue and yellow.) A forest green might have the same hue as the neon green, and perhaps the same level of saturation, but much less brightness. A pastel green might have the same hue and the same brightness as the neon green but less saturation. Likewise, a dark brown might have the same hue and saturation as the intense orange, but much less brightness.

So the three values that in combination indicate a color are hue, saturation and brightness. This is indicated by the acronym HSB, and is the simplest way to indicate a color value (for the purpose of this discussion.) Any color that you can think of can be indicated by a unique combination of hue, saturation and brightness (simplistically expressed - color theorists and Pantone agents out there don't toast me please, I am trying to simplify here.)

Technical side note: there are other methods to indicate a color value as well... RGB stands for Red-Green-Blue and is a representation of the control voltages in your monitor that control the intensity of the red, green and blue signals that you see on your screen; CMYK is Cyan-Magenta-Yellow-Black (yes, 'k' is black) and is from the printing industry and represents the amount of ink on paper to achieve a given color; LAB is Luminosity-A-B and represents the way that the eye sees color. There are others as well. HSB however is the most useful for this discussion.

So, in a color picture, every pixel has an HSB value. When you look at the picture, you see one area as bright orange and another as bright green because, while the saturation and brightness are the same, the hue is vastly different, and you see the forest green and the dark brown as different colors for the same reason. You can see the difference between a red rose and a pink one and an orange one because they vary in hue and saturation. You see the difference between a forest green object and a neon green one, or a gray and a black for that matter, because the brightness levels are different, even though the hue and saturation are the same.

In short, you are able to discern detail in the color photograph through variation in all three of the HSB values.

So why have we wandered off into color theory, and what does this have to do with getting a good black and white conversion?

OK, here is the important bit...

A color photograph achieves its detail through variations in hue, saturation and brightness. When you convert to black and white, the only variation that is available is brightness. This seems fundamentally obvious, but typically only in hindsight so it is worth saying again. The only variation that is available to indicate detail in a black and white image is brightness. Any information that was conveyed by change in hue or saturation in the color image must be mapped to a change in brightness in the black and white conversion, or that information will be lost.

So if you have a color picture of a red rose, a pink rose, and an orange rose, varying in hue and saturation but close to each other in brightness, and you convert that picture to black and white without taking this into account, all three roses will still be the same brightness level and will end up the same implied 'color' in the final image - probably not what you are going after. Things that appeared vastly different in the color image end up looking pretty much the same in the black and white, detail is lost, and you end up with an unsatisfying black and white conversion.

In the color picture above, the three roses vary only in hue and saturation, but not at all in brightness... this picture was chosen specifically to illustrate this point. This black and white version was created by simply doing a straight grayscale conversion.

As you can see, all the variation that came from the color component of the original image has been lost - these three roses might all be pink or orange or red or white for all we know, but the clear indication that our brain receives is that they are all the same color. The color information has been lost.

Once you get your head around the simple fact that you have three information vectors in the color image that have to be mapped into one in the black and white, then your job in making the conversion starts to become a lot more clear.

First you must analyze the image to understand what important detail is contained only in the hue or saturation and not the brightness, and is thusly going to be lost in the conversion to black and white. Then you take the necessary steps to map that detail to brightness in some way using the many techniques available, many of which fall into some variation of channel blending or curves, but the key always being that you are taking detail contained only in hue and/or saturation and in some way mapping it over to brightness, or taking detail already contained in brightness and enhancing it to compensate for the loss of the hue and saturation detail from the same area.

This is the key concept in black and white conversion, and once you understand it all the techniques you run across will start to make a lot more sense. Only once you understand this (relatively simple) concept can you reasonably tame the black and white conversion process.

I'll get into some specific techniques both for determining what detail is contained only in hue and saturation and as well for mapping it to brightness in upcoming posts as this is enough to digest right now, and certainly enough to have written at this hour of the night... :-) 'til next time, happy imaging and all that.

Photoshop Memory Usage

2005-12-23T14:44:00.000-08:00

I tend to keep my applications running for long periods of time without restarting... So the other day I look up and notice that Photoshop, with one 7MB PSD file open, is using 1.2GB of ram! It is a hell of an app that can bring a 2GB system to its knees just sitting there doing nothing but moving elements around and running a few filters, but Photoshop seems to go through memory like some people go through cars.

It uses some memory for a little bit and then says 'Oh I'm bored with this memory! It is cluttered and dusty and too small and the curtains are drab... I've heard about some great new memory down the way where things are shiny and the air is clean... Quick, lets go!'

And all the little Photoshop digital gnomes/gremlins/hamsters/nano-Knoll's gather up their hard hats and slide rules and hop in their golf carts and go speeding off to a different area in memory and look around and say 'Wow! Look at all this space! Quick, somebody plant a flag! Everybody, spread out - there's plenty of room! Quick now, run some filters!!' Chug-chug-chug-chug...

And THAT, I think, is why Photoshop is using 1.2GB of ram holding open a 7MB PSD file... just a matter of decor really.

Clearly I need more ram...

DNG Recover Edges Tool

2005-12-16T22:02:00.000-08:00

Did you know that most digital cameras capture more pixels than are finally output? If you look at the specs on your camera, you may see two numbers, sensor megapixels and 'effective' megapixels... the former is what the sensor captures, the latter is what you actually, for various technical reasons, get out of the camera.

But sometimes you REALLY want to recover those few extra pixels - often because of compositional issues, or perhaps you've just forgotten to take your OCD meds again. ;-)

A nifty little free utility from ultra-wizard Thomas Knoll (of Photoshop fame) allows you to do exactly that. There are some caveats, but if this sounds useful, check it out: DNG Recover Edges

Big props to Thomas for being such a very cool photographer-programmer dude and being one of the driving forces of the digital imaging revolution; he is a quiet guy who makes a big difference. And props to Michael Reichmann for hosting the download and getting the word out about it.

What is a camera RAW file?

2005-12-12T16:15:00.000-08:00

When you take a picture with your digital camera and look at it on the screen (either of the camera itself or later, on your computer), you aren't seeing a direct representation of what the sensor in the camera recorded - if you were it would be very dark and speckled and muddy looking with bad color and not really a very good picture at all. What you are seeing is the data from the sensor after it has been interpolated and gamma-adjusted and white-balance corrected and had a contrast curve applied and been sharpened and converted to a display color space and all kinds of other fancy techno-magic type stuff that your camera is performing on your behalf.

The camera is effectively rendering an interpretation of the image, and generally speaking the modern digital cameras do a pretty amazing job of this, but it is an interpretation nonetheless.

The analogy that is commonly given is to traditional photography: the data from the sensor can be thought of as the negative, and the preview that you see on the screen, and later the JPEG image that you download from the camera, are effectively prints of that negative, developed for you by the camera.

The camera is acting as a film lab for you, and doing a very good job in most cases, but no camera or computer can understand truth, beauty, art, aesthetic balance, and all that other blather. As good of a job as the camera does in most cases, with just a little practice you can do better...

And sometimes the camera just plain screws up.

So, simply put, a camera RAW file is effectively the raw data that the camera sensor recorded... un-interpolated, uncorrected, linear-gamma, and in need of lots of processing before it looks pretty. This is your digital negative, from which you can make many different prints of different styles and interpretations, and utilize many different digital darkroom techniques to achieve optimum image quality.

Having this level of ability and control over your final images is one of the most empowering aspects of the digital photography revolution, and shooting in RAW format takes it up to a new level.

In an upcoming post I will cover the unique benefits of working with camera RAW files more specifically, but in the meantime if you want to read a more-detailed explanation of all this, check out Understanding Raw Files over at the Luminous Landscape...

Quick Tip: Luminosity Blending to Avoid Color Shifts in Tonal Corrections

2005-12-08T03:01:00.000-08:00

Sometimes when you are performing tonal corrections on an image using levels or curves you introduce subtle (or sometimes not-so-subtle) color shifts as well. If this becomes a problem you can blend your tonal corrections in luminosity mode rather than normal mode - this will allow the adjustment layer to modify the luminosity of the image but not the color, and will prevent any color shifts.

You can extend this to any corrections you perform that are intended to be tonal in nature only... contrast enhancements, sharpening, and many other forms of tonal adjustment all can be limited in this way if they are causing undesirable color shifts.

Quick Tip: Non-destructive Dodge and Burn

2005-12-06T21:56:00.000-08:00

To perform non-destructive dodges and burns on a layer, try the following:

Create a new topmost layer (I usually name it DnB), set its blend mode to Overlay and fill it with the layer-neutral color (in this case RGB 128, 128, 128 - 50% black.) At this point your image should appear unchanged.

With the new overlay layer still selected, use the dodge and burn tools as you normally would; this will darken or lighten only the overlay layer, as opposed to the underlying image pixels. Don't worry if you go a little too far as you can always switch tools and reverse the effect in a specific area, and you can also reduce the opacity of the entire overlay layer to reduce the overall dodge and burn effect on the whole image.

Custom Black and White Image Conversion

2005-11-27T14:21:00.000-08:00

There are many methods to convert an image to black and white... straight grayscale conversion or desaturation, the luminosity channel, calculations or the channel mixer, or custom filters and plug-ins from a huge variety of providers, each yielding results of varying quality for different images.

All of these conversion methods come in handy, but often you will find that no single conversion method gives the best results for every part of an image. One part of the image will achieve the best tonal contrast using the red channel, another part using the luminosity channel, and yet another section of the image will look best using the green channel or a custom channel mixer blend or some other conversion method.

What to do? Can we somehow take the best parts from each method and combine them together into the ultimate black and white conversion?

Of course!

Pick the conversion method that gives the best results for the largest or most complicated part of the image and use that as your base layer for the custom conversion. Then put the result of each additional conversion method on its own layer and apply a mask to the layer to show only the part of that result that you want to use. In a landscape shot, for instance, you might find you get the best results using the red channel for the sky, the luminosity channel for distant mountains, and a bit of the red and a bit of the green channel blended together for trees (though of course every image is different and these are just examples of the type of things you can do with a custom conversion.)

It takes a bit longer than just changing the image mode, but for those special images it is well worth the trouble.

A more detailed tutorial that puts all of this in the language of traditional photographic filters is available from Jeff Schewe over at PixelGenius and is certainly worth a quick read...

Quick Tip: Local Contrast Enhancement

2005-11-19T20:14:00.000-08:00

To boost apparent contrast within your image, view at 100% and try the following settings in the Unsharp Mask filter:

Amount: 20%

Radius: 50

Threshold: 0

Turn the preview on and off to see the effect. Try varying the amount from 5-20% and the radius anywhere from 30-100 pixels to find the ideal setting, though the above starting settings are usually reasonably good. Typically higher resolution images require larger radius values, and lower-resolution images smaller radius values.

Ideally these changes will be made on a duplicate layer set to Luminosity blend mode to avoid any color shifts and to make the changes non-destructive to the original image.

The effect is subtle, but very effective. I use it a lot on images that seem a little hazy. Try it and see… if nothing else it is a quick one to try.

More information and a detailed explanation of how this all works:

Cambridge in Colour Tutorials - Local Contrast Enhancement

Luminous Landscape - Understanding Local Contrast Enhancement

Non-Destructive Photo Editing

2005-11-15T15:30:00.000-08:00

As a general rule, I always try to make my edits in Photoshop on a new layer so as to preserve the original pixels in their original form. This way I can always roll back or change my edits later, and if I notice unintended side effects from the processing I can more easily deal with it when all the changes are isolated and the original pixels haven’t been screwed up.

Photoshop supports this way of working quite well most of the time.

As an example, when I am applying an adjustment to an image I almost always do that on a new layer (Layer->New Adjustment Layer->…) rather than directly to the image itself (Image->Adjustments->…). This makes the adjustment on its own layer and does not change the underlying image pixels at all until the layers are finally merged together (either explicitly or by some action such as printing.) The adjustment can be enabled and disabled by changing the visibility of the adjustment layer, its settings can be refined or completely changed, masks can be applied, and variations can be tried (each on their own layer) to explore different moods or interpretations of the image, all without modifying the underlying image pixels in any way.

This way of working can be extended to most common tasks. For filters and dodges/burns and similar tools make a duplicate of the image layer (or a stamp on a new layer) and make modifications to that. When doing repair work with things like healing brushes and clone tools, create a new layer and make sure that layer is active and that Sample All Layers is enabled for the repair tool. (You may also want to disable visibility of your adjustment layers during repair work so that the adjustments are not applied twice to the repair layer.)

Keeping adjustments and modifications on their own layers is one of the neat ways of working that Photoshop enables. It just generally makes things easier…

For more on this, here is a good article on Safe Cloning that talks a lot about these principles specifically related to the clone stamp tool.

Digital simulation of RGB special-effects filter

2005-11-10T16:16:00.000-08:00

A friend of mine showed me an old photo the other day of a wave breaking on the beach and the places in the photo where there was movement had a sort of rainbow effect. Those who have seen this effect will know exactly what I am talking about.

This is easy to re-create in the digital darkroom - actually much easier than it was to do in film. Take three photos in quick succession (from a tripod or other stable surface) and bring them all into Photoshop. Convert them to monochrome and then assign one each to each of the three RGB channels.

Assuming your registration is good (you did use a tripod didn't you?), the photos will line up and in the areas that are not moving the image will be that of the original as all the RGB data is there, but where there is movement the different channels will add up in a somewhat random way to create the specific effect we are looking for.

Try it! It is quicker to try than to explain, actually, and if you don't know what the effect looks like this is an easy way to see it. Any photos that have both consistant and moving areas in them will work reasonably well: trees blowing in the wind, cars driving down a street, people walking on a sidewalk with buildings or something behind them - something moving and something still usually makes for a good candidate shot.

Pretty sure I learned this technique from Tim Grey's Digital Darkroom mailing list... somewhere buried in his archives I think there is a more lucid and detailed description of this whole process than I care to write (and than my friend no doubt cares to read) at this instant, though at this point I've lost track of sources. Tim provides some good information so he gets the shout out anyway... :-)

Tags: camera, photography, friends

Canon announces WiFi in the PowerShot line...

2005-10-28T21:27:00.000-07:00

Canon has added WiFi to their PowerShot line...

There are a couple things to sort out here yet, but the idea that you can, for instance, be pulling a wireless remote video feed from the camera and then trigger it from the notebook is pretty neat, and certainly not having to munge around with cables is always a good thing. The power hit is gonna suck though, and using it in the field with hotspots is years away at this point.

All the user needs to do is connect the supplied Wireless Print Adapter to a Canon PictBridge printer, such as the new Canon SELPHY CP510 or CP710 models, and press the blue lit Print/Share button on the back of the camera.

Amazing they are still pushing that proprietary interface. They must be not doing too well with the PictBridge thing if they are giving away the adapter...

So this means you get to assign an IP to both your camera and your printer? If this trend continues we are gonna need IPv6 sooner rather than later - pretty soon we'll be handing out IP addresses to wireless toasters.

Perhaps bluetooth might have been a better choice for this application, but of course the range sucks.

I think their press release misses the target a little bit, but this is a consumer camera - a market I am not familiar with. The way they talk it up, WiFi sounds useful for those photo sessions that take place entirely within your own house, and still reasonably useful in the field if you have a WiFi equipped notebook or other storage device, but this offering doesn't really address the way that most people use their cameras out in the real world. I won't go so far as Phil Askey over at dpreview.com and say that it is a 'solution looking for a problem', but it isn't quite as exciting as all that either.

One thing Phil says:

At home transfers will be no faster than dropping the camera in a USB dock...

Given the poor real-world performance of WiFi and specifically design limitations in the WiFi implementations in these devices, the transfer rates actually have the potential of being much slower than the wired solution... Canon's claim of full-frame video at up to 100 feet away will work fine for line-of-sight, but try doing that through a wall or between floors of a building and you won't get range anything like that... in the real-world WiFi is rather sensitive.

Unless you really NEED the WiFi, wait it out... next generation will address some of this stuff.

I'd rather see these things have EV-DO modems in them anyway - we have cell phones with cameras, how come we don't have cameras with cell phones?

Tags: canon, camera, photography, cameras

Kodak announces 39 megapixels!

2005-10-25T23:57:00.000-07:00

This is pretty amazing - gotta love how technology marches on...

Kodan launches high resolution CCDs

39 megapixels!

Yikes that is a lot of pixels... Wandering up into the BetterLight realm there, though I think that thing will do over 120 megapixels or something like that in its most intensive mode. We will all need screaming fast machines with 16GB of ram to process these RAW files.

The real key is the noise levels and the dynamic range though - chasing megapixels as an end in itself is a bad deal, but Kodak's medium format sensors are usually quite amazing once they go through their initial bug-fix iterations.

Good stuff! At least for those of you with LOTS more money than I have :-)

Tags: kodak, camera, photography, cameras

Apple trying to take on Photoshop

2005-10-23T18:30:00.000-07:00

Apple has announced Aperture, their direct hit at Photoshop...

In one sense, very smart move:

Mac already has good foothold with graphics designers

Apple has reasonably good insight into the creative process

Create software people want to use (key point there) that is only available on the Mac platform

On the other hand, very difficult:

Adobe is RIDICULOUSLY entrenched in this space - they are the de facto standard

Photoshop has huge market share

Graphics programs reasonably complex environment - changeover can be a drag

Will Aperture offer TRULY compelling features or capabilities that Photoshop and other products don't, and if so how long will it take those other products to catch up? Adobe is a pretty swift shop unless their fundamental arch is in conflict with the desired goal - end-to-end RAW processing being and example of one that might be a little tougher for them to strap on retroactively.

Temporal relationships between photos is the big 'Stacks' feature? Hmmn I say...

Apple sucks at software - they have gotten better, but they still have not proven that they don't suck... (No offense to all you Tiger lovers out there.) I used ClarisWorks damnit! I still wake up in a cold sweat ;-)

I must admit the native RAW workflow sounds very intriguing...

Prediction: Initial sales will be good, it will develop a small loyal following but never any really significant market share, cause lots of flame-wars on the forums, will end up being a drain on Apple's already rather limited technological brainpower resources and not a strong revenue provider either, and will end up with a light version bundled with new Macs and a premium version that they will end up supporting for a while then selling off to some other company.

Should they be taking on Avid rather than Adobe? Ah, but their machines don't have enough power for that... tough one.

Tags: apple, adobe, photoshop, photography

Epson 4800 mail-in rebate through Halloween

2005-10-20T15:40:00.000-07:00

Hmmn... Epson is running a $400 mail-in rebate on the Epson Stylus Pro 4800 printer through the end of the month. By all accounts this is a SWEET printer, though I still haven't seen actual samples. The reviews are hot though, at least on picture quality. The black-and-white images are supposedly amazing.

The ink costs are apparently through the roof though...

Tags: epson, printer, photography, printing

Moon Photo with Clouds

2005-10-17T13:52:00.000-07:00

A friend wrote and mentioned that he had been trying to take a night photo of the moon and the clouds - a photo that we have all seen many times - and was not getting the results he wanted...

The photo has great detail of the clouds, but the moon is a completely blown out spot of white.

Two things going on here:

1) Overexposure: Completely counter-intuitive, but when taking photographs of an unobscured relatively full moon you need to expose for daylight. The full moon is as bright as daylight, in other words. When you auto-expose using the meter for a night shot like this, the meter is exposing for the majority of the frame (more specifically for the particular sensor points for that camera's metering system) so it is exposing for the night sky - this is why you get good detail on the clouds but the moon is blown out... you need to expose for the moon itself if you want the surface detail, and the moon is a light brighter than you think.

This exposure adjustment can, by the way, still be done in fully auto mode if you can tell your camera to use a single point metering mode and then use the moon as that point... and I trust you know how to manually expose for daylight.

So, adjust your exposure and you will get a lovely shot of the surface detail of the moon, but of course what has happened? Now the rest of the night sky is massively underexposed and you can't see the clouds at all, bringing us to the second issue:

2) Dynamic range of film or digital sensor: neither film nor digital cameras have the dynamic range necessary to capture complete detail all the way from near black to bright sunlight - that is just too many stops for the camera to handle. Technology marches forward steadily in this area, but where we are now compared to where we need to be to achieve this shot in a single frame is a good ways apart. The current generation cameras just can't be expected to handle that much disparity between light and dark, and particularly when there is important detail at both ends of the range... Imagine a histogram for this shot - a big huge chunk at the bottom end, a big spike at the top, and very little in between... a very tough shot indeed from a technological standpoint.

So if you expose for the clouds, you blow out the moon, and if you expose for the moon you lose the clouds... what to do?

Here we use a technique that has been used in the film world for some time, but is much easier to achieve now in the digital age. Really a rather simple thing:

Set up your camera on the tripod for the shot and take a couple quick shots - using a cable release or your camera's remote will make things easier downstream. Take the first shot exposed for daylight so you get the brightness of the moon. Take the second shot using auto to expose for the clouds.

Bring the two shots into photoshop and line them up and mask between them to expose the moon from the first shot with the clouds from the second... then you end up with good surface detail of the moon and good detail on the clouds in the final image, overcoming the dynamic range limitation of the camera.

A beautiful night photo shall be yours!

In fact, if you want to you don't even really need to include the moon in the second shot - if you see some nice clouds nearby with good lighting on them then you can shoot that - it won't matter where the clouds are in the first shot as you won't see them anyway so you shouldn't have trouble lining them up. In many ways this is actually easier as it eliminates the issue of registration with the moon, and is usually what the traditional film guys would use as it completely eliminates the need to mask out the blown-out moon from the second photo.

Give it a try both ways and see what works for you.

Hope this helps...

I am pretty certain that I learned this technique from reading Michael Reichmann over at Luminous Landscape, although I just poked around real quick and couldn't find the link to the article itself. It is over there somewhere though I am pretty sure, and if not Michael deserves a link anyway... good author, good site.

Tags: photo, photography, camera, friends

Dream Camera - Canon EOS-1Ds Mark II

2005-10-11T23:17:00.000-07:00

Phil Askey over at dpreview.com has posted his review of the Canon EOS-1Ds Mark II, and it's a banger... 16.7 megapixels with a full-frame sensor - a serious camera! This is getting up into medium-format equivalence, or at least competitive range.

It looks like it has been improved in many ways, as one would expect from an $8,000 camera. 4992 x 3328 pixels - no problems creating a 17" print with that much data available to you... this camera would really demand a Epson 7800 to really utilize all these pixels.

The Canon has always excelled at night exposures, but these night shots are some of the best I have seen - that is a 30 second exposure there!

Great camera... me want! me want! In my dreams... :-)

Tags: photo, photography, camera, canon

Full-Frame Sensor Benefits

2005-10-08T17:49:00.000-07:00

A couple of people have asked why I care about the size of the sensor... rather than get into it all here and no doubt make plenty of mistakes, I will refer those who care to the reasonably accurate explanation of the benefits of full-frame sensors from the World of Canon CMOS Sensors site. While of course loaded with Canon marketing-speak, this is basically a fairly good quick explanation of the benefits.

Tags: photo, photography, camera

Canon EOS 5D with Full-Frame Sensor

2005-10-04T20:24:00.000-07:00

I know I am behind the times, but I just stumbled across the Canon EOS 5D - this sounds like the camera for me! I have always been concerned with the small receptor sites in the lower-end digital cameras; the full-frame sensor is the way to go, but I didn't want to spend $8000 or whatever the 1D costs, since you still need to buy a bunch of good lenses anyway.

Phil Askey over at dpreview writes in his EOS 5D Preview Article that he agrees with Canon's marketing assertion that the 5D

'defines (a) new D-SLR category'

... the availability of a 12.8M pixel full-frame sensor in a body that only costs a little over $3,000 is exactly what I need.

Then I'll need to start saving for those ridiculously expensive fancy fluorite lenses that you really need to take advantage of the full-frame sensor... as Phil points out, a camera this good will TEST a lens.

Fun stuff!

Tags: canon, cameras, technology