Tag Archives: lens - Page 2

Mirror lenses: worth it?

Posted by on November 10, 2010 8 comments

A few weeks ago I attempted to take some photos of the moon with my 300mm lens. The results were pretty good, but I wanted more, more, more! At 300mm, the moon is still quite small in the frame, and the photo I just linked was cropped a fair bit to “zoom in” some more.

The trouble is, telephoto lenses are expensive. I looked at various options and eventually got an excellent deal on an Opteka 500mm f/8 mirror lens.

Using a lens with a focal length of 500mm (or 1000mm with supplied teleconverter) was never going to be easy. At such a huge zoom, the tripod needs to be rock-steady, otherwise the image will move all over the place.

The Opteka 500mm lens was manual focus, like most (all?) mirror lenses. In principle this didn’t bother me, since I frequently use manual-focus Canon FD lenses. But in touching the barrel of lens, no matter how lightly, you send the moon ricocheting wildly around the viewfinder. You have to wait ten seconds for it to stop wobbling to see if your focus adjustment was any good.

Which brings me onto my next point. The focus ring is extremely sensitive. Even for an infinitely-distant object such as the moon, moving the focus ring just a millimetre sends the image to a blur. It’s a bit like using a rangefinder – when not perfectly focussed, there are two ghost images that slide past each other as you adjust the focus. I never managed to make them line up properly with this lens because it was too sensitive.

After an hour with the lens and camera on a tripod, I hadn’t managed to get a well-focussed picture of the moon. And in cases where I had got the focus not too far off, the general image sharpness was terrible, and there was considerable chromatic aberration. The following image is the best I got out of the mirror lens in an hour of shooting.

The moon

That could have been a really nice image, as the moon almost fills the frame.

I won’t give up just yet, but I’m reasonably confident that I won’t be able to improve on that picture. I might do better to buy a Canon 2× teleconverter to make my 300mm lens into a 600mm. I guess the L-series glass is a little out of my league for the time being :(

So, to answer the question in the title…

No. Mirror lenses are not worth it.

Review – Samyang 8mm f/3.5 aspherical Fisheye lens

Posted by on November 4, 2010 5 comments

The background

For ages I’ve wanted a decent fisheye lens. Back when I was shooting with my Fuji S9600, I bought a filter-thread screw-on fisheye adapter. It was only about £30 and the chromatic aberration was awful, even in the viewfinder. But it opened up a new world of photography to me, and I enjoyed using it, taking pictures like this self portrait and these shots of Bristol.

Fast-forward a couple of years and I upgraded my S9600 to a Canon EOS 450D. Presumably due to the larger sensor size, the fisheye adapter had practically no effect. I never used it again, but I missed it and I kept looking at proper fisheye lenses (as opposed to the fisheye adapters). I rather liked the look of Canon’s 15mm fisheye lens. Trouble is, it has a list price of £880 (although can be had for around £600 on Amazon). For an occasional-use lens, this is just too much.

Recently I had another craving for more fisheye photos and I decided to have a look at third-party options.

The manufacturer options

Of course Nikon and Canon do their own lenses, and most of the “big name” lensmakers such as Sigma and Tamron also have offerings. But there are also some from lesser-known names. Peleng, Samyang and Opteka all offer fisheye lenses for Canon SLRs for around the £200-£250 mark.

It seems that the Samyang and Opteka lenses are virtually the same, although they have different advertised focal lengths – 8mm and 6.5mm respectively. I haven’t quite worked this one out yet, but I think it’s because of the projection that is used. I settled upon the Samyang since it’s available for a few pounds less on eBay and Amazon.

Samyang 8mm

Samyang 8mm

I was a little hesitant about buying a lens from a virtually unknown manufacturer. £200 is in that “danger zone” where it’s too expensive to risk wasting the money, but not quite expensive enough to be sure you’re getting something that’s any good. So I read some reviews, primarily these:

Amazingly, both reviewers gave the Samyang lenses a glowing review. They both noted that there is some chromatic aberration, but for the price, this can’t be argued with.

The thing that’s most likely to throw a spanner in the works is that this lens has no electronics. It can’t communicate with the camera, so there is no autofocus and no automatic aperture. This isn’t a problem for me, since I usually use Canon FD lenses which are also fully mechanical. But be aware, if you don’t like manual focus, think twice before buying this lens.

My thoughts

There’s nothing so formal here as a detailed review. I haven’t taken any measurements, but I can say a few things about using this lens.

  • When mounting or removing the lens from the camera body, it’s really hard to hold and twist the barrel of the lens without also twisting the aperture ring. I know it’s hardly a big deal, but it stands out from all my FD-mount lenses in this respect.
  • Having no electronics, you have to use the camera in aperture-priority or full manual mode. In Av mode, my 450D seems to consistently overexpose the image by about 11/3 stops. This is easily fixed with exposure compensation.
  • Again having no electronics, you have to manually open up the aperture when composing your shot, and then stop it down for taking the photo. If you don’t, the viewfinder can be very dim and difficult to focus.
  • The lens feels heavy and expensive – I guess due to the large glass elements inside. The focus ring is damped and feels much nicer than the manual-focus mode on most of Canon’s newer EF-mount lenses.
  • Despite some warnings about chromatic aberration and flare, I saw very little evidence of this in my photos. I deliberately challenged the lens in unusual lighting conditions by taking silhouettes against the sun and so on, but they all came out nicely.
  • Aside from adding some electronics, there’s not much that can be improved about this lens. For the price, the optics are incredible.

Sample photos

I can’t be bothered to duplicate my photos on this blog, but you can see the results of my evening photo-walk to the Clifton Suspension Bridge over on my photo blog ;)

My Tamron 90mm macro lens

Posted by on May 27, 2010 7 comments

I quite enjoy macro photography. When I used to use my Fuji S9600 as my main camera, it had a super macro mode, which allowed me to focus on objects as close as 1cm. That was pretty handy for macro shots and the results were generally good – such as this disgusting pupa.

Since swapping the S9600 for a Canon EOS 450D DSLR, I don’t have a macro facility. The best I could get was my Tamron 70-300mm telephoto zoom lens which allowed 1:2 magnification at full zoom. But the subject had to be at least 1.5m from the camera and image quality wasn’t great, so it wasn’t really a solution.

I bought a set of EF mount macro extension tubes from eBay. These sort of replicated the behaviour of the S9600, by allowing the camera to focus closer. By spacing the lens further from the camera body, it’s possible to focus down to just a few millimetres away from the end of the lens, so tiny objects can fill the frame.

However, as EF lenses are electronically controlled, you lose autofocus and the ability to shoot with the aperture anything other than wide open. Naturally, the depth of field is then very shallow. Sometimes it works, like in this photo of a pound coin, but it’s quite frustrating not being able to stop down.

The other disadvantage of “cheating” at macro by focusing closer is that it’s hard to get light onto your subject, because the snout of the lens casts a shadow. When I use my macro LED ring flash, some of the objects I photograph have to be so close to the end of the camera that they are within the ring flash and hence get no light.

So I decided the only real solution would be to buy a proper macro lens with 1:1 magnification. I considered the Canon 60mm macro as the cheapest entry-level macro lens, but unfortunately it’s EF-S mount and can’t be used on 35mm SLRs, such as my EOS 300. If I’m going to shell out for a lens, I want it to work on all my cameras.

The next lens up in Canon’s range is the 100mm macro, which is EF mount, but is unfortunately quite a bit more expensive. I watched a few second hand lenses on eBay but the auctions always closed for prices significantly higher than I was willing to pay – especially as macro photography is only an occasional treat for me.

The two main rivals of the Canon 100mm are the Tamron 90mm and the Sigma 105mm. The Sigmas are rarer but there were plenty of Tamrons on eBay. The first few auctions for the 90mm finished at quite high prices but eventually I found one ending at an awkward time and won the auction for a bargain price. The lens is second hand but very new; mint condition and boxed in all original packaging.

The main disadvantage of the Tamron compared against the Canon is that the Canon has an ultrasonic autofocus motor, and full-time-manual focussing. As nice as those things are, they weren’t worth an extra £150 to me. The Tamron lens flips between manual and autofocus by sliding the whole focus ring back and forth, which is much nicer than fumbling for a small switch on the side of the lens barrel.

The Tamron 90mm feels solid compared with some of my other lenses – most of them budget ones. It’s reassuringly heavy and feels like an expensive lens. The autofocus is quite slow and quite loud, but this doesn’t matter. When I’m composing a macro scene, I can take all the time I like.

The main gripe is that the lens barrel extends by about two inches when focussing. You have to be careful not to bump into your subject if you are working at close range.

I’ve only owned the lens for a few hours, but I can see it’s a fantastic lens. The images are very sharp and almost completely free from any aberration. When I have some time to experiment with some small subjects, I’ll see what I can come up with. But for the time being, here’s a picture of a piece of Velcro.

Two months of DSLR ownership

Posted by on May 8, 2010 No comments

Back in September 2009, I was given a 35mm SLR camera – a Canon AE-1 Program. I loved it, it was fantastic to use, and I wrote a blog post about the possibility of upgrading to a DSLR.

In March 2010, temptation got the better of me and I bought a Canon EOS 450D. My main concerns beforehand was the loss of the large LCD viewfinder of my Fuji S9600, and in particular, not being able to flip it out for awkward shots, and not being able to see useful information about the camera settings in the eyepiece.

Well I needn’t have worried – the 450D is of course more advanced than my AE-1 and has a small LCD under the optical viewfinder for that information. I hadn’t realised until I tried it out in the shop.

The issue of having to put my eye up to the camera still hasn’t been addressed, but it hasn’t been a problem. I just find myself lying on my belly more, or simply pressing the button and guessing about the composition.

In the two months that I’ve owned the 450D, I’ve taken over 2,000 photos[1] and I’ve thoroughly enjoyed all of them. I feel more in control of the photos, and I can’t recommend an SLR strongly enough to anyone who is serious about photography.

I now have three EF mount lenses for this camera. Unfortunately they don’t fit the AE-1 (which uses the FD mount) but this very evening I bought a Canon EOS 300, which is a consumer-level 35mm SLR with an EF mount. You can pick up 35mm camera bodies on eBay for a fiver so I thought it might be nice to make even better use of my lenses.

If you’re actually interested in any of my camera facts and figures, you might like to look at my page of cameras. If you’re more interested in the pictures themselves, then why not browse my photo blog.

[1] That’s about 1.4 each hour I’ve owned the camera

Tagging photos by camera

Posted by on March 24, 2010 No comments

I’ve decided to start tagging all of my new posts from now with the camera and lens they were taken with. At some point I will probably work back through the archive (250 posts!) and tag those too.

You can now find photos taken with:

This probably won’t interest most people, but it’s a handy reference for me. Anyone who is interested in cameras and lenses might also want to see my Cameras page, or the photography posts on my geek blog.

Review – Tamron 70-300mm lens

Posted by on March 23, 2010 6 comments

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 2nd 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 :)

Lens within a lens

Posted by on February 1, 2010 No comments

This a candidate shot for this week’s Photo Challenge theme – glass. I’m not sure if I like it that much, but time is ticking away so it might have to do.

Building a pinhole camera

Posted by on November 26, 2009 1 comment

The other day, I was suddenly taken by an urge to build a pinhole camera. I vaguely recall building one out of a shoebox at primary school that projected a dim image onto some tracing paper, but now that I have the equipment and a little experience in developing films at home, I thought it might be fun to make a pinhole camera that can work with film to make permanent images.

Medium-format sheet film is the ideal thing for such an application. While I have the stuff to develop 120 film, I don’t have any means of scanning it. So my system will be using regular 35mm film, which is more convenient for me.

This got me thinking about how to mount the film in the pinhole camera. Obviously when using small film, the camera needs to be shorter to project a smaller image. Could be fiddly to load individual frames of 35mm film into an oxo box! So I wondered about using the body of my Canon AE-1 Program, basically as a film holder.

But I wasn’t sure how easy it would be to cut a hole in the side of a cereal box and shove a camera in there without letting light in. So I considered building a pinhole camera around the body of my AE-1. Maybe I could jam a toilet roll tube into the FD mount, or something.

Then I found this much more sensible guide, Making a pinhole lens for an SLR. It describes how to make a body cap into a pinhole “lens”. It’s completely light-proof, easy to make, and causes no damage to the camera (assuming you have a second body cap).

So, I’ve ordered a body cap from eBay and I will be making it into a pinhole “lens”. I will, of course, scan and post the results on my photo blog. There will probably be some kind of review on this blog, too. Watch this space!

Playing with a fisheye lens

Posted by on September 16, 2009 2 comments

Today my fisheye lens arrived. It’s not a whole lens for an SLR camera; rather an “add-on” lens that screws into the filter thread on my Fuji S9600 or any other lens.

I’ve tried a few ideas with it, and been as creative as one can possibly be in a boring flat on a lazy evening.

First, a badly-focused self portrait:

Me

And an uninspiring shot from my balcony – a view that has appeared on this blog many times before.

A view over Kingswood

I think I’m going to have fun with this lens.

Photography for beginners: Filters

Posted by on September 13, 2009 No comments

Filters are pieces of glass that screw onto the front of your camera, and they can cause all sorts of unusual effects to your photos.

The good news is that you can buy filters cheaply from eBay (and of course, less cheaply from the high street, if that’s how you like to buy). Before buying, you’ll need to know the diameter of your camera’s lens. This should be written somewhere on the lens barrel or often around the glass on the front of the lens. Look for something like Φ58mm, and then check that your lens has a fine screw thread inside the rim. You’ll need this for the filters to screw into.

Of course each camera (and potentially each lens, if you have an SLR) may have a different lens diameter. If you’ve built up a large collection of filters and you plan on changing camera, never fear! You can buy adapter rings that allows you to use the “wrong” size filters on your new camera.

So let’s have a look at the various kinds of filter you can buy. This list is by no means exhaustive!

Ultraviolet (UV) These filters are designed to filter out UV light, which is invisible to the eye but can cause haze in outdoor photos.

As they are so cheap, it’s worth keeping on one the front of your camera permanently to prevent the lens from scratches.
Infrared (IR) IR filters remove all light except infrared light. It can give an eerie night-vision type effect, or give interesting photos of hot objects – such as the sun or a light bulb. Example.
Neutral Density (ND) ND filters simply cut down the amount of light entering the camera. Think of them as sunglasses for your camera. With an ND, you can set a longer exposure in daylight, or it allows you to keep the same shutter and open the aperture a bit wider for increased depth of field.ND filters come in a variety of darknesses. The most common types are ND2, ND4 and ND8, which allow through 1/2, 1/4 and 1/8 of the light respectively. If you’re not sure which to buy, try an ND4 first.
Circular polariser (CPL) Polarisers cut glare from reflective surfaces such as glass or water, and enrich the colour of the sky.
Soft focus / diffuser These filters add a gentle blur which can improve the appearance of skin in portraits, or add a slightly dreamy feel.
Graduated ND (GND) These filters are almost clear at one edge, and dark at the other edge, fading slowly across. You can use a graduated ND to darken and enrich the sky while leaving the foreground unaffected.
Star These filters cause points of light to appear as stars. You can get them in 4-point or 6-point varieties.
Skylight Skylight filters reduce the bluish tinge that can occur when shooting in daylight.
Graduated colours These are graduated filters with a colour. The most common ones are blue and orange – for emphasising the colours if the sky during the day, or at sunset.

These are the rules of thumb that I’ve come up with through experimentation. Hopefully they’ll be useful:

  • Always keep a UV filter (or at least some other type of filter) on the lens to prevent scratches
  • Consider replacing the UV filter with a Skylight filter when shooting outdoors to avoid a blueish cast
  • Use an ND filter when shooting in very bright light to avoid overexposed areas
  • Use a CPL or a GND when shooting landscapes with large areas of sky, to make the sky dark and rich
  • Consider using a diffuser when taking close portraits to soften skin tones
  • Any of the other filters are generally for novelty effects and are not subtle
  • Try to use only one or two filters at any one time. Every filter you add can decrease the quality of the lens system, and if you stack up three or more filters, you can usually see the rim of the filters in the photo.

So if you fancy trying something different, I recommend getting some cheap filters from eBay and seeing what interesting effects you can come up with.

Next time, I will write about basic photo editing on a computer.