Tag Archives: Sony 18-250

Horsing about in the dark

At XMAS, I took some pictures of my daughter riding and jumping her horse, Bazil. It was a quiet day at the stables, no-one else around, so we had the arena to ourselves.

What we didn’t have was a great deal of light. We were there late morning but it was gloomy and overcast, hardly any shadow. My challenge was how to get some usable shots.

I wanted some pictures of Bazil jumping but it was very hard to get a fast enough shutter speed on my Sony A100. It was also very hard to get the lens to focus. In the low light the focus mechanism was either too slow or simply unable to work properly. Time after time it would miss with the focus. I had to resort to manually pre-focusing the Sony 18-250.

This is how I went about it. I picked a place to stand by the arena fence, near the jump, and focused on the bar of the jump with the lens at 250mm (so I could see when it was properly in focus). I then turned off the auto-focus and set the lens to 18mm, mainly to get away with the slowest possible shutter speed, and set the aperture to maximum (F3.5). ISO was set at 400, the fastest I dared risk without inviting unacceptable noise.

The camera was on Aperture Priority and the shutter speed was coming out at 1/400th which was just fast enough to freeze the action. The camera has built-in image stabilisation but that doesn’t help to get a moving horse sharp.

It was then all about waiting for Esther and Bazil to come around the arena, reach the jump and go over it. As they approached I would start a series of frames on continuous shooting.

The hope was that one of them would catch the peak of the action. I hadn’t brought a tripod so I stood against the fence for support.

Esther kept changing rein so the horse would then be moving away from me as it approached the fence. I had to wait until Bazil was going the right way again. The results aren’t too bad. A bit affected by noise, and I couldn’t get in tight with any of the shots, but I did get some worthwhile action pictures.

I also managed to catch Bazil with all four hooves off the ground.

This was a bit of a fluke. Esther thinks I took the picture at the instant of a flying change of rein.

The ten best pictures from the day are here.

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Sony 18-250: The turn of the screw

It doesn’t seem to be spelled out anywhere but Sony’s DT 18-250 F3.5-6.3 lens does not have a built-in focusing motor, relying instead on the motor in the camera body. This goes some way to explain why there have been some complaints that its focusing performance is a bit slow.

Actually, the complaints are more specifically directed at the equivalent Tamron lens which most definitely does not have a built-in motor in Alpha mount guise, although Tamron did incorporate a motor in the Canon mount variant. Sony (who own a substantial stake in Tamron) did more than just rebrand the Alpha mount version when making it available as a Sony label product, but clearly did not go so far as introducing a lens-motor.

Sony rounded the aperture blades to improve the bokeh, and they did take action to improve focusing speed, but the latter took the form of changing the gearing so fewer screw turns are required from closest focus to infinity.

It was a compromise, among many compromises, to produce an attractive high performance package at an affordable price point. I guess adding the motor would have added significantly to cost, and the ultimate in focusing speed is of less critical importance to the target market (keen amateurs) than if they had been targeting professionals. My feeling is that they were right. I don’t know how slow the Tamron Alpha mount version feels in use but I have not ever felt particularly bothered by slow focus with my Sony 18-250, even at longer focal lengths and in lower light. So maybe the faster turn of the screw added up to a sensible compromise. Certainly, I am happy with the value for money the lens represents, but it was still not cheap and I would have had to think twice if the price had been very much higher.

More widely, the trend seems to be decidedly towards built-in lens motors, certainly so far as Canon and Nikon are concerned. Sony seem to be reserving built-in SSM motors for their premium lenses with fancy prices. So be it. I can live with that.

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Ironing Pile

It is very frustrating when you have just taken delivery of a new camera lens but have neither the opportunity nor the weather to put it through its paces.

This is the best I could think of, my wife’s ironing pile:

My first effort with my new Sony DT 18-250 f3.5-6.3

My first effort with my new Sony DT 18-250 f3.5-6.3

You can click the photo to see it in higher resolution.

I had been bemoaning the inadequacies of my ageing Tamron 18-200 (71D) which performed OK for years with my Minolta film SLR, but had been producing disappointing results with its replacement, the Sony A100 DSLR. I think the problem is down to the fact that the Tamron had just enough resolving power when allied to a 36mm film frame, but not a 24mm APS-C DSLR sensor. The cropping effect was asking too much of a lens already at its limits, even though the crop was picking out the centre of the frame, where the lens should be at its sharpest.

Add the poor contrast and flare control, and you have a pretty weak package.

I now have the Sony 18-250, made for them by Tamron (ironically) and based on a proven design which has been very successful for Tamron in recent years. If reviews are right, it should be streets ahead of the creaky 28-200 in terms of performance.

It is obviously too early to draw conclusions about the new lens. I am though delighted to get some semblance of wide angle back – at its widest I now get the field of view equivalent of a 27mm lens. And I already get the sense that this new lens has distinctly more bite than my old Tamron, and richer colours.

It will (I hope) be fun finding out more about how it performs. On subject matter more interesting than ironing piles.

First published here 10 August 2008 on my Windows & technology blog Hasta la vista, Vista!

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