Thursday, September 07, 2006

Using A Manual Lens With The Nikon D50

Buster (100E Test 2)

"You've attached what to your Nikon D50?"

As part of my ongoing project to hamstring my Nikon D50 digital SLR, I tried it with my old 100mm f2.8 E series manual focus lens. The series E lenses were plastic-bodied AIS lenses designed for the budget Nikon EM SLR back in the 1970's; I bought one years ago for my manual Nikon FM camera, as snobbery among collectors about the plastic construction meant you could get these excellent lenses at knock-down prices second-hand (the lens elements are all glass, of course, and very good too).

The first effect of fitting a manual lens to the D50 is that the metering system is completely disabled; without the CPU inside even the oldest AF-Nikkors, you get nothing, neither matrix metering, centre-weighted nor spot. The aperture readout on the top plate LCD and in the viewfinder reads "--" and none of the automatic exposure modes will work. You have to switch to Manual exposure mode, and, unusually for the D50, set the aperture via the aperture ring on the lens.

For a metered exposure, you'd need either a handheld incident meter or a second camera. Luckily, I'd used an old non-metered Rolleiflex TLR for a number of years, and had got used to 'guesstimating' exposure. A great advantage of digital is that I could take test shots and adjust accordingly. Much to my satisfaction, my guesses were mostly within about a stop of the right result.

Plant (100E Test 1)

My original estimated exposure for this was only one stop over.

Focussing is, naturally, manual, but I was pleasantly surprised to find the D50's electronic rangefinder still works; this shows a green dot in the left-hand corner of the viewfinder when the subject in the focussing brackets is sharp. You can go a bit cross-eyed trying to keep the centre focus brackets in position while monitoring the in-focus dot, but it works well enough; sadly, the D50 doesn't possess the useful direction triangles (telling you which way to turn the focussing ring) that were present in the finders of my old F4 and F801s. Given the speed and accuracy of the D50's AF, I can see why this is; I only use MF as a way of locking focus or when setting focus to a given distance for depth focussing* - either way, I almost never fine-focus manually.
I had thought that the focussing screen for the D50 was fixed, but since Katz Eye Optics make a split-prism screen with microprism collar for the D50, I guess it must be interchangeable. I'm not sure if Nikon make a compatible manual focussing screen, but there evidently is a third-party option if you were thinking of using manual focus a lot.

Teeth (100E Test 3)

Grab shot - it was about 1 2/3 stops under, but rescuable in Photoshop - like slide film, digital images respond better to slight underexposure.

So results; well, it wasn't as convenient as shooting with an AF lens, obviously, but it was a lot easier than I'd feared. Although it was a bit awkward to use, having the electronic rangefinder for reassurance made a big difference. I was surprised that I managed to get decent shots of a moving target like my mum's cat, and even a grabbed candid (above) using this camera/lens combination.

Not being able to meter the exposure slowed things right down (having an incident meter to hand would have made a lot of difference) but given a bit of experience and the ability to make test shots, it was surmountable, to the extent that if you predominantly shot static subjects (i.e., still life or plants) under reasonably controlled conditions, you might not even miss having a meter. If you were shooting at night with (auto) flash and a pre-focussed wide-angle manual lens, you could also bypass focus/exposure issues.

The D50 obviously isn't intended for use with manual focus lenses, but, depending on what you shoot and how you shoot it, you might be able to keep on using an old favourite. A couple of caveats though; bear in mind that the D50's chip is smaller than a 35mm film frame, so multiply the focal length of your lenses by 1.5 to get the new angle of view - in practise this means that your wide-angle lenses will become less wide-angle, in fact even lenses as wide as 28mm really stop being wide-angle at all.
Secondly, not all old Nikkor lenses can be attached to the D50 - in particular, there seems to be a long list of exclusions among the teleconverters, bellows and PC-shift lenses. I'd strongly advise checking lens types and serial numbers with Nikon (or seeing if your local dealer will let you look in the back of a D50 manual) before buying.

*setting the focus for a given distance with a reasonably small aperture and using depth-of-field to keep subjects within a given range in focus.

Friday, September 01, 2006

Animal Experimentation With The Fuji E550


Don't worry, it's only artistic experimentation - dogs in the post office, Gijòn

I first noticed the Fuji Finepix E550 after checking out the shooting data for Dr.Beef's excellent cat pictures on Flickr, wondering how she got such spontaneous shots of her furry friends. The answer came a few months later when my friend Irma Page showed me her E550; she was taken with it for its high resolution, I was astonished by the speed with which it powered up and took shots. I was using two Canons; a PowerShot S50 and a PowerShot G3, both excellent cameras, but not the fastest beasts on the block.

I'd been looking to upgrade my S50 for a while, but when I discovered you could get a Nikon D50 SLR body for less than the compact I was then considering, the Canon S80. The chance to use my old Nikon lens collection again was too much to resist, so I gave up on upgrading from the S50. But then, while talking to Irma, she mentioned that E550s were being sold off very cheap (probably due to the introduction of the E900), so I had a look on eBay, and here we are...

I won't bother with a detailed description of the E550 as those nice people at DPReview have done a much better job of it than I ever could; the short version is the E550 is a just-about-pocket-sized, rather boxy and unlovely-looking camera with full manual control, a 32.5-130mm (35mm FoV) f2.8-5.6 zoom and 6.3 megapixels that can be interpolated in-camera up to 12.3 megapixels using Fuji's "Super CCD" system.
It runs, usefully, off AA-sized batteries; I use NiMh rechargeables, but it will take ordinary alkalines if you're caught short. It has a built in discharger to help prevent battery memory problems.

Button Portrait

You lookin' at me?

So, how did it perform? I'd had it for a while when I decide to really test the shutter-lag (or lack thereof) and continuous shooting against visiting cat Button, who was being steadily driven kill-crazy by the swarm of dragonflies flitting around our garden this afternoon. The first challenge was to see if I could capture a simple portrait - often tricky as a cat will usually look in any direction except at you when you're pointing a camera at him. My usual experience with cats and Canons was of sitting there like an idiot, making a variety of squeaking, whistling, clicking and popping noises until one of them finally piqued the cat's interest, at which point I'd be rewarded with a fleeting glance, which I'd miss by 1/8 second due to the camera's shutter lag.
No such problems this time - lots of squeaking and clicking, true, but two out of two glances caught successfully, of which the one above is the best.

Button Flipping

Believe it or not, he's heading out of the frame here...

Next came the attempt to capture Button in action. Whenever a dragonfly strayed within range, Button would go for it by leaping backwards and up, so that he performed a complete backflip. Seen out of the corner of the eye, this gave the impression someone was hurling him across the garden like a boomerang.
It was hellishly difficult to capture because the leaps came suddenly and at random, though usually in pairs, followed by long periods when the cat would be getting his breath back. Button also tended to leap farther than I expected; this meant my first few shots consisted of random bits of kitty anatomy poking in from the edge of the frame.
The important thing to note, though, is that I was getting the cat in mid air; my reflexes and panning skills might not have been up to tracking a pinwheeling furry maniac, but the camera was keeping up with both of us.
I decided to try the continuous shooting next, and that was my downfall. Because the Canons were so "laggy", I'd developed the technique of continuous shooting from just before I thought something was going to happen, in the hope that the frame burst would catch what reflexes could not. The E550 has two continuous modes; one takes four shots at 3fps, then stops to write the pictures to the card. The other mode will capture an apparently limitless number of frames, also at 3fps, but only save the last four pictures shot. This allows you to keep shooting until you see the shot you want, rather than having pre-empt the action and hope it will occur during a limited shooting burst. Furthermore, that 3fps is pretty scorching for a compact - in fact it's better than my D50 SLR can manage.
I set the E550 to the latter continuous mode, then waited for Button to spring. Up he went - perfectly centred in the finder for the only time that afternoon - but then, much faster than I expected, another four frames went through the camera and my perfect shot was lost. I was left with four frames of a cat landing on a lawn (which looks not dissimilar to a cat crouching on a lawn, and not at all like a cat hanging in mid-air over one, perfectly centred in the frame.)

Button Charging

Button flees my belovèd, the startling Dr. F.
Why, I don't know; I'm the one who trod on him...

Since Button's bursts of motion were so short I decided to try the more usual "shoot four and save" mode - this worked much better, as you can see above. I think this was originally frame two of a set of four.

So, on a first quick try, the E550 does what I bought it for; catches the moment quickly and discreetly. There's stuff I don't like about it - the macro mode is poor, the zoom has trouble focussing in low light at the long end, the JPEG compression options are limited and it's possible to wipe the XD card by carelessly disconnecting the camera from your computer - but as a carry-anywhere candid digital camera it's the best thing I've found so far, especially for the (second hand) price.

Focus Tracking Tests With The Nikon D50 And Older AF Lenses

(The photographs shown here are uncropped and uncorrected. I've posted them on my Flickr account at full size, so you can download them to examine if you wish.)

After being held up by work, I'm finally getting round to writing up the tests I did with my D50 and my telephoto lenses. The D50 has a useful focus mode called "AF-A" - this defaults to single-shot AF, but will switch automatically to continuous focus (focus tracking, in fact) if the subject it's locked on to starts moving continuously towards or away from the camera.

I was a bit wary of this setting, but it works like a dream; it doesn't seem to cause focus lock problems in single-shot mode, and the transition to continuous focussing is pretty reliable (though it does work better the longer the focal length of the lens - it seems happiest at 85mm upwards). I now leave my D50 on this setting all the time.

Lenses and settings

28-85mm @85mm
85mm prime lens
80-200mm @ 80mm
80-200mm @ 200mm (3 sequences)

All are pre-D Nikkors, the 85mm and the 80-200 zoom are the old type with the locking pin on the aperture ring.

AF was set to use the central focus point. Mode: AF-A.

The D50 controls aperture via a dial on the camera body, so the aperture ring on the lens has to be locked for all modes, even aperture priority and manual.

Details of the focus tracking tests

On our local high street, I tried tracking approaching cars moving at 20-30 mph from a set of road markings about 100m distant, until they passed me.

28-85@85 05.JPG

28-85@85 11.JPG

Sample first and last frame from a test sequence taken with the 28-85mm zoom at 85mm (click on images to see full size version)

With each lens, the D50 managed about 7 shots in the same distance. I couldn't time the tests and also shoot, but I'm guessing that the camera was shooting a little below its maximum burst rate - what you'd expect, given it was focus tracking at the same time. Focussing at 80mm (FoV 120mm) was accurate and also consistent, despite the differences in maximum aperture and the physical bulk of the three lenses. The D50 has no trouble driving the big 80-200mm zoom.
At the 200mm (FoV 300mm) setting, accuracy started to suffer - of the 25 shots I took at 200mm, 5 were unsharp, one unusably so (the camera had focussed some distance behind the target car). But to put that in context, 58 out of 59 shots were as good as or better than I'd have expected to manage by the only other technique available - pre-focussing on a spot in the road and waiting for the vehicle to pass.

More problematic was the tendency for the shutter speed in Aperture Priority to drop as the approaching car filled the frame; sequences starting at 1/350sec would drop to as little as 1/60 sec by the last frame, resulting in camera shake. I'd expected the matrix metering to compensate for this, and it's possible that a D-type lense might cope better. It's worth noting that it 's better to use manual exposure mode for this type of shooting.

80-200@200  7.JPG

80-200@200  8.JPG

Sample shots affected by camera shake - but if you look at the seam line on the bonnet, they're still in focus (click on images to see full version)

It still has to be said, these results are significantly better than I expected, and better than anything I've achieved with my film SLRs. I never considered focus tracking to be a serious tool before, but I'll now be using it, particularly with that conventient AF-A mode.

80-200@200 B8.JPG

Sample shot from 80-200 zoom, this time without camera shake

The fact that the 1gb SD card on the D50 will routinely hold 360 images at JPEG Fine (83 more than the counter suggests when the card is empty) makes me willing to use the "motor drive" much more than I ever would have when shooting film, though I'm not sure if that's actually a good thing or not.

Recently I had a chance to repeat the tests with an AF Nikkor 70-300mm f4-5.6 D lens; the D specification had no effect on exposure, though it did routinely manage one more frame per sequence than any of the non-D lenses. While it's no surprise that it could focus faster than the bulky 80-200 zoom, I'm surprised at it out-performing the fast 85mm prime. At the 200mm setting, the D lens focussed more accurately than the 80-200mm, the lighter construction presumably offsetting any disadvantage from the smaller aperture.

70-300D@200 09.JPG

70-300D@200 28.JPG

End shots from two sequences taken with the AF Nikkor 70-300mm f4-5.6 D Zoom - note the camera shake still present in the first shot due to shooting in Aperture Priority mode with a dark-coloured car filling the frame.
The second shot is was taken in Manual exposure mode with a shutter speed of 1/800sec - this was the last shot from a prodigious run of 13 consecutive frames, all in focus.
(Click on images to see full size version)

I thought this would be where any cracks in the D50's performance would appear, and I was happy to be proved wrong. I'm not saying that the D50 will give the ultimate in performance when fitted with an old AF Nikkor lens - I'm sure a new G-type zoom would give better results (as, for that matter would a D2X) - but the fact remains that if, as I am, you're trading up from an early-90's film SLR and you don't want to ditch your old AF lenses, you can be confident that the D50 will give at least as good a performance as your old camera, if not slightly better. What's more, the D50's FoV conversion factor of 1.5 means that your telephoto lenses all effectively become longer - so my 80-200mm zoom now gives the same field of view as a 120-300mm zoom on a 35mm camera, and my 70-300 zoom acts like a whopping 105-450 zoom. Not bad for a budget solution.