Jonathan's blog

If you want to take photos at the so-called “super telephoto” range, then you have a few options. They have relative costs and relative merits. Let’s go through the main ones.

Genuine super telephoto lens

I’m a Canon shooter, so I will refer to the Canon lenses – but the same applies to Nikon, Sony and others.

If you’re doing it by the Canon book, and you want a 500mm lens, then you are supposed to go out and buy a Canon 500mm or 600mm (or longer) lens. At the time of writing the 500mm and 600mm telephoto primes are £8,280 and £10,820 respectively.

Canon EF 500mm f/4.0L IS USM

That’s a lot of cash to throw at a lens. It might pay off for a professional sports photographer, but for an amateur like me, a specialist lens like this would only see occasional use.

There are third-party options, such as the Tamron 200-500mm and the Sigma 150-500mm. These are both priced at under £1000, but do not offer the same quality as the genuine Canon lenses. The quality would be fine for my uses, but a thousand pounds is still too much for me to spend.

Tamron SP AF200-500mm F/5-6.3 Di

As I said, I don’t have any of these lenses, so there isn’t a sample picture in this section.

Mirror lenses

On the face of it, mirror lenses seem like a cheap way of getting a very long focal length. For under £100 you can buy a 500mm mirror lens.

Opteka 500mm f/8 Mirror Lens

Even on the outside of the box we can get an indication of how crude these lenses are. They are fully manual-focus. There is no electronic communication with the camera body. The aperture is fixed, and is usually quite slow (e.g. f/8). They are usually manufactured by names you’ve never heard of before. The sample I tried was the 500mm mirror lens from Opteka.

I knew this before buying, and I was happy with the risks. I have a collection of old cameras so a manual, mechanical lens is nothing new to me. In the end I was extremely disappointed with the lens for two reasons. The sharpness was very poor, and the manual focus ring was extremely sensitive. It was near-impossible to get the moon in focus.

This is the best picture I managed with it. It’s blurry and there is a lot of chromatic aberration. And this was with the moon – imagine trying to take a photo of a bird in flight with this lens. Forget it.

The moon

I wrote a post on my blog entitled “Mirror lenses: worth it?“. You’ve already had a taste of my sentiment here, but there’s more detail in that post.

Preset lenses

Preset lenses are a sort of halfway house between mirror lenses and proper telephoto lenses. They use glass lenses rather than mirrors, but are otherwise like the mirror lenses. They are fully manual, no electronic control and either a fixed aperture, or a choice or 2 apertures that can be flipped in and out of the optical path. If you’re lucky it might have a diaphragm.

Opteka 500mm f/8 Preset Telephoto Lens

Pretty much the same conditions apply to these as to the mirror lenses. They’re slow, hard to focus and have poor quality glass. Some people online have posted surprisingly good pictures, although I think these are the exception, rather than the rule. Opteka (among others) sell a 500mm preset lens.

I don’t own a preset lens, so there’s no sample picture in this section.

Teleconverters

Last but not least, I’ll cover teleconverters. These are small adapters that fits between your lens and your camera body, and increase the focal length, either by 1.4× or 2×.

Kenko Teleplus MC7 2x Teleconverter

The advantage is that you can use your existing 300mm lens, or buy one. They are common, and not too expensive. In most cases, there is a small loss of sharpness but usually this loss is acceptable.

I bought a Kenko Teleplus MC7, which is one of the cheaper teleconverters, at a little over £100. There are also superior offerings from Kenko (£145) and Canon (£236).

I already owned a Tamron 70-300mm zoom lens which came as a bundle with my DSLR, but can also be bought for around £100. Almost every lensmaker sells something that can reach 300mm. Adding a £100 teleconverter has given me a 600mm lens, with autofocus (in bright light), with proper lens glass and a variable aperture. It is a far superior solution to a preset or mirror lens.

Aside from some loss of sharpness, the other main snag is that you lose two stops of exposure from your lens. For example, my Tamron lens has a maximum aperture of f/5.6 at 300mm. With the teleconverter, it’s stopped down to f/11. This isn’t enough for the autofocus to work except in very bright sunlight. Bear this in mind. Fortunately, manual focus on the Tamron is nice and the ring has enough granularity to be able to focus accurately.

While not perfect, within minutes of attaching the teleconverter I took several photos like this.

The moon

Summary

So my advice to anyone wanting to move into longer focal lengths is to buy a teleconverter for your 300mm lens. If you don’t have a 300mm lens, buy one with a teleconverter. It’s much cheaper than a Canon L-series telephoto lens, and much, much better than messing around with a mirror or preset lens.

Recently I bought a Canon EOS 450D from Jessops. They were running a bundle deal, and it came with a Canon 18-55mm lens and a Tamron 70-300mm lens.

The long zoom was quite an important aspect to me, since I had upgraded from a Fuji S9600, with a huge range in focal lengths.

I’ve now owned the camera for a couple of weeks and I’ve had a chance to play with it a bit. Of course a fortnight isn’t nearly enough time to fully understand everything about a complicated device such as a DSLR, but I’ve tried a few things with it.

This review in particular is about the Tamron lens.

Obviously you don’t expect wonders from the cheapest lens in its class, but I am still quite disappointed. The S9600 was a jack of all trades (and master of none) and showed weaknesses at both ends of its range of focal lengths. That said, the whole camera cost around £200 and can now be bought for significantly less than £200. I think that represents fantastic value for money. During my 23-month ownership of it, I’ve taken about 10,000 photos. On average, that’s more than one every two hours!

Given that the Tamron lens on its own costs almost as much as the entire Fuji camera, I had hoped for significantly better images. Never mind.

At the shorter focal lengths, it’s OK. Nothing to write home about, but it’s fine. I took these self portraits at a focal length of 70mm and they seem OK.

But when you start to zoom in, the problems get worse. Some of this should have been obvious from reading the box – its largest aperture at 300mm is f/5.6, which is pretty slow. To make matters worse, there is no image stabilisation. You can’t complain about this – it says it on the box and if you want a fast lens, you have to pay more for it.

But I wasn’t at all pleased with the optical quality at 300mm. Take, for example, this photo of some distant horses. The first photo is the full image, and the second one has been cropped to show detail. Neither photo has had any other editing.

Horses in Hartshill

Horses in Hartshill

The first thing you might see is that the focus is very soft. It wasn’t camera shake because the sun was out and I used a tripod. The autofocus just seems to struggle at long focal lengths.

But then look at the chromatic aberration around the white horses. It makes the image look pretty terrible.

I also tried taking some photos of the moon last night, also at 300mm. As before with the horses, it couldn’t autofocus properly. The low light conditions made it much worse and the image was so blurry that there was no definiton on the surface of the moon.

I flipped the lens into manual focus mode where I was able to hugely improve the focussing. Unfortunately it seems in manual focus, as you approach infinite focus, the moon becomes sharper, but for the last little bit of the travel the lens goes beyond infinite focus and makes a garbage image. Not good at all.

In the end, this is the best I could manage. Here I used manual focus, spot metering and I’ve cropped the image afterwards.

The moon

It’s OK, but I’ve managed a better photo of the moon with my S9600.

I’m not sure if my lens in particular is faulty, or if these lenses are all equally bad. But I am very unimpressed with the results, even for a budget lens. Given how much more the 450D and this lens cost than the S9600, there is no excuse.

Tamron’s own website says:

Perfect 2^nd lens for your DSLR kit

So they are certainly admitting that it shouldn’t be your primary lens. However I would also hesitate to say it’s “perfect” for anything.

My advice would be to avoid this lens, unless you’re on a particularly tight budget, or you don’t plan to use the higher end of the zoom range. Be prepared to switch off the autofocus, and focus manually if sharpness matters. Get a Canon telephoto lens if you can.

Update

I may have been a bit hasty in my critical review. As I said in my comment below, I had another go today at taking a few photos with the lens.

First here’s a chimney stack at full zoom, and a cropped version below.

Chimney stack at 300mm

Chimney stack at 300mm (crop)

As you can see, the focus is very sharp. There is a little aberration, but that’s expected from a cheap lens.

This photo of the seagull was also taken at full zoom. The autofocus can be pretty slow going from one end of the focus to the other, but if you focus on a similar object first, it’s much faster. In this case, fast enough to get a lock on a swooping seagull.

Seagull

Yes, it’s not perfect – but it’s acceptable for the price. I’m going to keep this lens and see what I can achieve with it