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Nikon Owner Issue 17

Technical Q & As

3D COLOUR MATRIX METERING II - WHAT ADVANTAGE DOES IS OFFER?

Question: Simon, Can you tell me what differences there are between 3D Colour Matrix metering, and 3D Colour Matrix metering II (Two)? Henri

Answer: Dear Henri, Any especially bright highlight, or large highlight area, relative to the size of the focused subject, would typically cause earlier Matrix metering systems to calculate a conservative exposure value, particularly in D-SLR cameras, in an effort to retain highlight detail. Even if the highlight(s) that caused this to happen did not form an important part of the overall composition, they would still influence the overall exposure, and thus in certain circumstances the main subject might not be exposed as accurately as it could be.

The latest version of Nikon Matrix metering, 3D Colour Matrix metering II, introduces an additional algorithm that detects the size (area) and brightness level of any highlight(s) within a scene, regardless of whether they are focused or not, and applies an exposure compensation to achieve a more balanced exposure of the mid and dark tones. The effect is subtle but clearly perceptible, although any camera that supports 3D Colour Matrix metering II will still attempt to maintain highlight detail by preventing overexposure.

The system works the other way round as well. So if the focused subject is a light tone against in otherwise dark surroundings, the 3D Colour Matrix metering II algorithm will work to preserve the brightest tones in the subject without undue influence from the darker sections of the composition. Regards, Simon.

CHROMATIC ABERRATION ON THE FISHEYE DX 10.5MM F/2.8G

Question: Dear Simon, I was shooting with my Nikkor Fisheye DX 10.5mm f/2.8G lens and D70s over the weekend and was very surprised to find heavy colour fringing in the extreme corners of some of the images.

Nikon state that this lens uses ED glass so I am surprised to see what I presume is a high degree of chromatic aberration, or is it something to do with the sensor?

Are all Nikkor DX 10.5mm lenses like this or is this unusually bad, and is there anything I can do to reduce the problem? Thanks for your help. Best wishes, Adrian.

Answer: Dear Adrian, Your presumption is quite correct; the colour fringing you observed toward the edges and corners of the image is caused by lateral chromatic aberration. It is the result of very slight variations in the refractive index of the lens with different wavelengths of light. As a consequence, the magnification of the image alters towards the extremities of the projected image and the effects of lateral chromatic aberration are manifest as a colour fringe around the edge of elements in the picture.

I have not tested a sufficiently large sample to comment definitively on the performance of the Fisheye-Nikkor DX 10.5mm f/2.8G in respect of its ability to control lateral chromatic aberration but it has been present in all three that I have used. However, I have detected a difference in the level exhibited by these examples, which tends to suggest some are better or worse, depending on your point of view, than others.

If you shoot using the NEF RAW format you can use the colour aberration control in Nikon Capture Editor to help reduce the effects; with Editor open go to Image > Color Aberration Control. (Note: This option is not available with multiple exposures or pictures created using image overlay options on the D2X.) Many other third-party image manipulation applications have a similar feature. Simon.

CHOOSING A LENS

Question: Dear Simon, I am thinking of buying a macro lens for my D 70 but I am not sure whether to get either the 60mm f/2.8 or the 105mm f/2.8 AF Micro-Nikkor. What are the advantages and disadvantages of each?

I currently own an AF Nikkor 70-300mm but find that I am not able to fill my lens with birds and similar subjects, so I am also looking to buy a telephoto lens for the D70. Should I get the 80-400mm f/4.5-5.6, or the 200-400mm f/4 AF-S VR Zoom Nikkor? Thanks for your advice. Regards, Bridget.

Answer: Dear Bridget, One of the most important specifications of a macro lens is its working distance. This is the distance between the front of the lens and the subject. To enable the use of supplementary lighting or reflectors, and to reduce the risk of disturbing a live subject it is desirable to have the greatest possible working distance.

At their respective minimum focus distance, the working distance of the 60mm lens is 90mm, and for the 105mm it is 135mm.

Another important consideration is the angle-of-view of the lens as this will have a direct bearing on how much of the background is visible at any given focused distance. Generally, it is preferable to have a narrower angle-of-view to isolate the subject from its background.

Therefore, if you are looking for a general-purpose close-up / macro lens the AF 105mm f/2.8D is probably the better bet but do not take my word! I recommend that you visit a dealer and try both in 'the hand' first.

As far as a longer zoom lens is concerned the AF-S VR 200-400mm f/4G is an outstanding lens and will easily outperform the VR 80-400mm in terms of its optical quality and AF performance by a country mile! However, such performance comes at a price, as the 200-400mm is about four times more expensive than the VR 80-400mm lens.

You may want to consider an alternative combination of the AF-S VR 70-200mm f/2.8G and TC-14E II (1.4x) teleconverter. It may not have quite the reach of the other two lenses but the AF and optical performance surpass that of the VR 80-400mm. Regards, Simon.

WHICH SPEEDLIGHT SHALL I USE?

Question: Dear Simon, I own a D1X, SB-80DX flash, and a D70, which is used as a secondary camera but also as back-up the D1X. However, I am concerned that I do not have a back-up flash unit and wonder whether I should get another SB-80DX, or go for the SB-800? Also, how do I set-up these flashes to trigger wirelessly? Thanks, David.

Answer: Dear David, Your current equipment puts you in something of a predicament!

As a pair the D1X and SB-80DX offer TTL flash control using the earlier iteration of Nikon's flash control system for digital SLR cameras, which is known as D-TTL (Digital-TTL). Unfortunately, D-TTL does not support TTL flash control for multiple flash units regardless of whether they are connected by a hardwire or used wirelessly. The only way to operate multiple flashes in D-TTL is to select either manual flash, or standard automatic flash that is controlled by the sensor built-in to the SB-80DX, and use cables or the SU-4 flash controller unit to trigger the flash units.

It was limitations such as this that drove Nikon to develop their latest i-TTL (Intelligent-TTL) flash control system that supports TTL control of multiple Speedlights, wirelessly. However, this is only available with i-TTL compatible cameras (the D1X does not support i-TTL, and nor does the SB-80DX; the D70 is i-TTL compatible, and you can even use the camera's built-in flash as the master flash unit to control remote SB-800 / SB-600 flashes, although in this mode the built-in flash does not contribute toward the main flash exposure as it only emits the command signals to the other flash units), and the SB-800 or SB-600 Speedlights (the former can be used as either the master or remote unit, whilst the latter can only be used as a remote unit).

To run a pair of remote Speedlights operating with TTL flash exposure control, via wireless commands, you would need at the very least your D70 plus a pair of SB-600 Speedlights, although neither could be used as the master flash, so you would have to rely on the camera's built-in Speedlight to perform that role, with the limitations as described above. A more flexible system would probably be the D70 plus one each of the SB-800 and SB-600, with the SB-800 offering the potential to be used as the master flash. For the greatest level of functionality, use the D70 with a pair of SB-800 Speedlights.

If you use the SB-600 or SB-800 with your D1X the flash control defaults back to D-TTL, and the only way to perform multiple flash photography is with either full manual flash exposure control, or using standard automatic flash. Remember, there is no support for TTL control of multiple Speedlights in D-TTL!

Adding another SB-80DX to your current system takes you no closer to being able to operate flash wirelessly with TTL flash exposure control. Adding a single SB-800 is little better, although at least this can be operated wirelessly from the D70 (using its built-in flash) but not the D1X. I am sorry to say that to get a wireless TTL system going with the D70 your hand is going to have to go even deeper into your pocketů Regards, Simon.

THE WAY TO A HEALTHY-LOOKING SKIN

Question: Dear Simon, Please could you advise me if there is any way of dealing with minor scratches on Nikon camera bodies?

We all know that during its working life a camera body / lens is going to get knocked about at some point, no matter how careful one is. For example, I was using my D2x the other day and just scuffed the top plate on some fencing.

The mark/scratch is very minor but naturally I REALLY want to look after the camera. Do you have any suggestions on keeping a camera in top condition? (Apart from not using it and keeping it in its box!) Many thanks, Richard.

Answer: Dear Richard, Maintaining a pristine cosmetic appearance to your equipment is almost a contradiction to actually using it!

However, the effects of light scuffs and knocks can be mitigated by applying liberal amounts of adhesive tape to areas such at top & bottom plates, edges and corners of camera bodies, and around lens barrels, all areas that tend to pick up light marks quite quickly regardless of how careful you are. Just make sure that by taping equipment you do not obstruct access to any controls, or impede its operation in any way!

Storage is one factor that is often overlooked - do make sure that your equipment is retained securely inside whatever camera case/bag(s) you use, because it can pick up marks from abrasion against interior surfaces whilst being transported.

Regularly cleaning of the exterior surfaces of equipment is also to be recommended to prevent the effects of corrosion by moisture, particularly salt water, and atmospheric pollutants. Regards, Simon.

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