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Photography

Vibration reduction with Nikon lenses

Nikon builds vibration reduction into some of its lenses, as does Canon. Not all Nikon’s lenses have vibration reduction and for very short focal length lenses it is not necessary. Vibration reduction, or image stabilization as some other manufacturers call it, stabilizes the camera. It does not stop the subject moving so it is no advantage in sports photography where very fast speeds are required. But it is useful in low light.

In the Nikon Imaging site, a Mr Kazutoshi talks about the development in vibration reduction technology in Nikon lenses. He says that VRII, the second generation incarnation of this technology means that:

The detection of the low frequency band in camera shaking has been greatly expanded, so the VR effect has become available even if the shutter speed is quite slow. I believe that a VR effectiveness equivalent to about four stops in shutter speed covers most shooting conditions. When we were test shooting during development, we couldn’t assess the effectiveness of four stops in shutter speed until well after the sunset, so we had to shoot through the night for some time.

For those not familiar with what four stops in shutter speed means, cameras are designed so that there is a constant relationship between the aperature and shutter speed. Each stop opening up the aperture, doubles the light that gets into the camera during the shot. And shutter speeds double in the same way, so that it is meaningful to measure an increase in one stop of light by saying it is equivalent to a doubling of the time the shutter remains open.

So translating this into what we can acheive with Vibration Reduction on a Nikon lens, let’s suppose I am shooting a lens with a focal length of 135mm and that I using a camera with a crop factor of 1.5, (which means all of Nikons DSLRs with the exception of the new D3, which is full frame).

So the 135mm lens has a field of view equivalent to a 200mm lens (more or less) in a full frame 35mm film camera, which is the standard that focal lengths for lenses are described against.

Now it is generally accepted that to be pretty sure of getting a sharp shot hand-held, the slowest shutter speed should be no slower than the reciprocal of the focal length, in other words for a 135mm lens on a digital SLR with a 1.5 crop factor, the slowest shutter speed I should use is 1/200th second.

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Photography

Window

Window

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Photography

Menu settings on the D200 – hue adjustmet

I have been getting some odd results with shots of greenery. So today I reset all the menu settings. This is done by pressing two buttons on the top plate – ‘QUAL’ and ‘+/-‘ for a second or so until the information in the top LCD blinks and resets.

I was not sure whether this resets every setting in all the menus, and anyway I wanted to work my way through all the settings to make sure they were where I wanted them to be. I am away from home at the moment, so I googled for the D200 manual and came up with Ken Rockwell’s guide to the settings. It can be downloaded as a pdf, but looking at it in his site enables one to hyperlink to different references.

So I discovered that I had the hue setting in SHOOTING MENU > Optimize Image > Custom > Hue Adjustment, set to -3degrees. I have no idea when I did it, but having done it, I decided to google for hue adjustment in the D200. None of the people whose stuff I read suggests altering it and Ken Rockwell says ‘leave it alone!’. Which begs the question of why it is there.

Pressing the info (‘?’) button on the D200 brings up a the following. “Hue adjustment: Adjust color hue. For example, choose positive values to make skin tones more yellow, or negative values to make skin tones redder.”

Which is more of a mystery because I cannot imagine I would ever have wanted to make skin tones redder. It is just not something the D200 needs, because it exposes skin tones very nicely without adjusting hue.

Which leaves the possibliity that I adjusted it ‘blind’ while I was intending to do something else.

Hue corrected to ‘0’
after

The bottom line is that having seen the result of adjusting hue in the camera settings, I second Ken Rockwell’s opinion – leave it alone.

It may be that the adjustment setting can be re-adjusted in Camera Raw in Photoshop, but I have not had much success and as there are several sliders to move, it is not something I want to do as a matter of course.

Hue

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Photography

The Nikon D300

Everyone who had followed the Nikon and Camera brands of SLRs over the past several years expected that Nikon would bring out models to compete with the new Canon models. So it is no surprise that they have with the Nikon D3 and Nikon D300. The D3 is the first full frame (that is, the sensor is the size of a frame of 35mm film) that Nikon has produced. And that is all I am going to say about it, because lusting after it (price $5,000) will not get me one, and the D300 has many features that make it interesting and desirable in its own right.

Features of the Nikon D300
It has 12 megapixels compared to the 10 megapixels of the D200, so the change in image quality from the pixel count is so small as to be discounted. But the sensor uses CMOS technology, unlike the D200, which has a CCD sensor. And it is a proprietory Nikon sensor. And the image processing is 14-bit.

These three features imply that the image quality will be substantially improved over the D200, that the high ISO image quality will be tremendously improved and that battery life will also be improved.

14-bit
The extra bit depth of 14-bit technology (rather than the 12-bit that Nikon and Canon employ at the moment) should mean fewer blown highlights. Blown hightlights occur where an overdose of light hits all or some of the microlenses and reduces the image on those parts of the image to blank white, from which no detail can be recovered.

Small areas of blown highlights are often not a problem, but it’s a different story if it affects all the white petals on a flower, or the bride’s white dress, or the side of someone’s face that is turned to the sun. Compact cameras are notorious for blowing highlights, mainly because each microlens in the array is so small that it is easily overcharged in a high contrast scene.

14-bit technology means more steps are capable of being read between dark and light, which should result in a smoother gradation from dark to light areas.

Whether this increase in bit depth translates into images that looks good depends on the processing technology within the camera. That is something we will have to see when the first images are taken and the samples posted. I hope to post some samples. The potential is there – it remains to be seen how well Nikon (and for that matter Canon with their offerings) translate this into images that have the pzazz of a well-converted 8-bit jpeg.

Thankfully, photography is still at the mercy of the light striking the sensor chip. Which means that attractive lighting – early morning light on a dull day, late afternoon winter’s light, gentle north light filtering into a room – still drives the photographer’s quest for what will make a good image.

CMOS and CCD technology
With a CMOS sensor chip, the electronic charge generated by the light hitting the microlenses is amplified via transistors on each microlens and the values are read individually. With CCD technology, the charge across the whole array of microlenses on the sensor chip are read at one corner of the array. Both technologies are capable of making high-quality images but Canon, using CMOS technology, has shown that this seems to have a distinct edge at high ISO.

And this for me is the real break with traditional 35mm photography, because the ability to shoot at ISO 3200 and get clean images, takes the opportunities for where and when one can photograph, into a place that was unknown to film photography.

With a fast lens – say something between f1.8 and f2.8, one can think of taking atmospheric portraits in low light that were not possible with film – at least not without flash (which changes the scene completely) or without using very high speed film that had its own limitations.

One of the other advantages of CMOS technology is that it is less demanding on power. This should mean improved battery life for the D300.

More features
Add to the features of the D300, a self-cleaning sensor, an LCD that has an astounding 922,000 pixels (the D200 has 230,000), liveview in the LCD (so you can see what you are going to shoot, rather than just what you have shot), and dimensions and weight more or less the same as the D200, and Nikon have probably held on to their lead. The lead they have built over the past six months is that they have outsold Canon SLRs.

D300

Whether it is the big guns like these cameras that are making the difference, or whether it is the D40 that is giving Nikon its lead, I don’t know. One thing that is clear though, is that both manufacturers are still in the game, which benefits consumers of all stripes. It would have been a pity if one or the other failed to make advances in technology, for that would only mean the market would stagnate.

And as for images of the new cameras from Nikon, well Nikon is kind enough to supply a whole page of web-ready images for people to use. Which strikes me as a sensible sign of the times when a manufacturer gets everyone who wants, to be an ambassador and advertiser for its products.

D300 top

D300 back

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Photography

Nikon D200 and Nikon D40 comparison shots – testing for color quality

An open book laying in long grass is a good subject for a test of sharpness in the lettering on the page and of the tonal values and color quality of the plants and leaves.

I shot the scene with the D40 with the 18-55mm kit lens, with the focal length set to 24mm, and at SO 200.

I then took a similar shot with the D200 with the 12-24mm lens, with the focal length set to 24mm, and again at ISO 200.

I shot both images hand-held as I was primarily interested in the overall image quality and the fact is that I shoot almost all my images hand-held. The rare occasions when I use a tripod substitute is when I find a convenient wall or table for low-light shots.

Moreover, I have already tested these two camera and lens combinations for sharpness (see earlier posts) and I have determined that for all intents and purposes the differences in sharpness are so small as to be ingnored.

Of course the 10 megapixels of the D200 as against the 6 megapixels of the D40 determine how large a print can be made before the appearance of the image starts to degrade. But there are such good image-upsizing products on the market now that even the maximum size one can print to is no longer written in stone.

I shot both images in RAW and opened them in CameraRaw 4.1 in Photoshop CS3. One of the nice things about Camera Raw 4.1 is that you can open two images at the same time and apply the same settings and go back and forth between the two images to see what the effects are. The settings I applied were to increase exposure by a little under half a stop, and to increase sharpening from 25 up to 92 in each image.

The full frame shots are 1000 pixels wide so I have only posted the thumbnails on this page. Click on the thumbnails to see the full-size shots.

D40 full frame
D40fullframe

D40 crop
D40crop

D200 full frame
D200fullframe

D200 crop
D200crop

Over a range of images I have taken with these cameras, my conclusion is that the D200 produces richer color and a more natural look. But in these two images I leave you to draw your own conclusion about the quality of the color in both full frame images.

I am going to put some more comparison shots up in the next few weeks.

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Photography

And which Canon lens?

Canon makes a huge range of lenses and they are coming out with three more to coincide with the arrival of the two new dSLRs they have just announced (see my last post).

The three new lenses are the EF 14 mm F2.8 L II USM, the EF-S 18-55mm f/3.5-5.6 IS, and the EF-S 55-250mm f/4-5.6 IS.

But none of these is the one I would choose as my principal lens, at least not for a mid-telephoto zoom. I would choose a lens which is known to be sharp, has a constant aperture, and which also has image stabilization.

That lens is the Canon f4, 24-105mm ‘L’ series, .which retails at $1,000 more or less.

Canon L