a dead cockroach

My dad buys and sells all sorts of things, and occasionally will buy some camera gear, even though he has no idea of its value. He recently bought some lenses, and asked me to take a look at them, to see what they were worth.

This particular collection of old lenses included a couple of Hanimex lenses, a Makinon lens, and a Sigma lens. The lenses were pretty old, didn't have lens caps, and were pretty banged up.
Some research indicated they weren't worth much - but the thing that intrigued me was a dead cockroach inside one of the Hanimex lenses, so I took a few photos of the lens and the cockroach inside it, to share on my blog.

taking a closer look - the front legs have become detached, with one near top right, and one near top left

I recently started having focus issues with my most-frequently used lens, the Canon EF 24-70mm f/2.8L. It would often rear-focus a lot, despite using only the centre focus point and single-shot focus mode. This rear-focusing behaviour didn't occur all the time, and it seemed to occur more frequently at wider focal lengths.

There was also some in/out movement in the lens barrel that I previously hadn't noticed, and I suspected that this movement was related to the focus issues.

Canon EF 24-70mm f/2.8L lens

Here's an example photo, showing the bad rear focussing behaviour. The photo was taken using the centre focus point only, and single-shot focus, focusing on the face of my oldest son.

photo straight out of the camera

While the rear-focusing isn't particularly obvious in the scaled-down photo above, the 100% crop below shows it much more clearly.

After reading a recent post by Jason, where he analyses the focal lengths he uses, I was inspired to do something similar.
I performed a similar analysis on all the photos I took in 2010, looking at which lenses I used most, and the focal lengths used. This was done in light of the fact that I have been thinking about maybe selling one of my lenses and getting one covering a slightly different focal length.



ExposurePlot is a useful application for performing analysis on your photos. Just point it at a directory of your photos, and it reads the EXIF data in all the photos in that directory and subdirectories, and generates graphs of the data.

The command-line exiftool provides similar functionality, but requires a little more effort to process the results.
For example, to extract the focal lengths of all photos and dump the results into a text file (recursively going through all subdirectories looking for photos), the following syntax can be used:

exiftool -r -focallength * > focallengths.txt 

If you are a Lightroom user, Lightroom can report various statistics by lens, aperture, focal length, and more. Just click the filter combo at the top right, and select "Metadata" to view the filter criteria.



During 2010, I took photos on numerous work-related interstate trips, visiting Sydney (twice), Adelaide (three times), Brisbane, Gold Coast, Roxby Downs, as well as a road trip through various locations in NSW, including Newcastle, Wollongong, Nowra and Botany Bay.
I also shot one wedding, did one family shoot, and took plenty of photos on several holidays with my own family.

moth and everlasting flower

Lesmurdie Falls National Park, Lesmurdie, Western Australia
Canon EOS 50D, 24-70mm f/2.8L @70mm, 1/1000 sec, f/4.5, ISO400

I have previously written about 35mm being a natural focal length on a crop-sensor Canon DSLR body, as it provides a focal length that's quite close to 50mm on a full-frame DSLR body.
Because I don't find the 50mm focal length of the Canon 50mm f/1.8 to be very natural on my 50D body, I bought a Canon EF 35mm f/2 lens, and have been really enjoying it so far.



Here are some photos of the Canon EF 35mm f/2 lens.

side view

front view

I spent several hours on Saturday afternoon, replacing the ribbon cable to the aperture diaphragm assembly in my Canon 17-85mm IS lens.



As mentioned in an earlier post, my Canon EF-S 17-85mm f4-5.6 IS USM lens has been failing with "Err 99", and some testing indicated the aperture diaphragm assembly in the lens was failing under the following conditions:

• zoom was between 17mm and 24mm
• aperture was smaller than f/4

Apparently this is caused by broken connections in the ribbon flex cable to the aperture diaphragm assembly in the lens, and is a relatively common occurence with this lens.

I bought a replacement cable on eBay from these guys for approx AUD$12, with free shipping from Hong Kong, as I had decided to try repairing the lens myself.

new aperture ribbon cable

I'm not going to provide a step-by-step guide to disassembling the 17-85mm lens, as there are already a few such guides that I found useful:

• EFS 17-85mm IS f4-5.6 Err 01 Err 99
• Repair of an Canon EFs 17-85 IS lens

There are also some more photos from someone who completely disassembled their 17-85mm lens available here.

By following the above-mentioned guides, I was able to disassemble the lens, and replace the aperture cable. Here's a few photos showing various stages of disassembly.

I'm in a predicament. My Canon EF-S 17-85mm f4-5.6 IS USM lens is dying.

I purchased it brand new about 4.5 years ago, have taken many photos with it, and have found it to be a great general-purpose zoom lens. A couple of years ago, I bought a Canon EF 24-70mm f/2.8L lens to replace it, but kept the 17-85mm for my children to use.



Last week, while on a photography road-trip with my two boys, my oldest son was using the 17-85mm lens on his Canon 350D camera. Focusing was fine, but any attempt to take a photo would result in the 350D showing "Err 99" on the LCD, and the camera had to be turned off and back on to clear the error.
"Err 99" is a generic catch-all error code on the 350D, and can mean almost anything (lensrentals.com have a great article on Err 99).

Trying the 17-85mm lens on a Canon 50D resulted in a more specific error: "Err 01 - Communications between the camera and lens is faulty. Clean the lens contacts."
Not surprisingly, cleaning the lens contacts with a pencil eraser didn't do anything to resolve the error.

50mm prime lenses are quite popular - and this is apparently because a 50mm lens provides a similar focal length to the human eye. Most lens manufacturers sell a cheap and fast 50mm lens, and I have previously reviewed the Canon EF 50mm f/1.8 lens, which retails for just USD$100.

My primary camera is a Canon 50D DSLR, and due to the size of its APS-C sensor, it has a 1.6x crop factor. This means a 50mm lens on an APS-C camera body has the same field-of-view as an 80mm lens on a full-frame camera body (ie, 50mm * 1.6 = 80mm).

While I like the Canon 50mm f/1.8 lens, I've found a 50mm lens on an APS-C camera body just a little too long, and started looking at slightly wider alternatives.

To achieve the equivalent field-of-view with an APS-C camera body that a 50mm lens has on a full-frame camera body, a lens with a focal length of around 31mm is required.
In the Canon lens range, there are a few options near this focal length, including various lenses at 24mm, 28mm and 35mm.

After keeping an eye on second-hand lenses on eBay, I managed to win a Canon EF 35mm f/2 lens at a pretty good price.
A 35mm lens on an APS-C camera body results in almost same field-of-view as a 50mm lens on a full-frame body - giving the same field-of-view as a 56mm lens on a full-frame body.

Canon EF 35mm f/2 and Canon EF 50mm f/1.8 II lenses

In the few weeks since buying the 35mm lens, it been the primary lens on my camera! I've been enjoying the focal length, and find it to provide a more natural field-of-view on my 50D than the 50mm lens.

I have already posted a few photos taken with the 35mm lens, and I'm intending to write a more comprehensive review of the 35mm f/2 lens in the near future.


Update (November 2010): I have now published a review of the Canon EF 35mm f/2 lens.

As far as Canon lenses go, the 50mm f/1.8 is probably the cheapest, smallest and lightest (130gr) lens in the Canon range. However, that doesn't mean it's not worth looking at!

It's a prime lens (ie, fixed focal length lens), with a maximum aperture of f/1.8. This makes it a great lens for low light situations, due to the large amount of light it'll let in at its maximum aperture.

This large aperture also provides a very short depth-of-field, which is great for portraits, allowing you to have the subject in focus, but the background blurred.



Here's some photos of the Canon EF 50mm f/1.8 II lens.

side view

front view

I've always believed that glass (ie, camera lenses) is more important than the camera body. When I bought my first DSLR, a Canon 350D, rather than buy the Canon EF-S 18-55mm f/3.5-5.6 II kit lens, I opted for the more expensive Canon EF-S 17-85mm f/4-5.6 IS lens. I didn't see the point in putting a ~AUD$150 lens onto a ~AUD$1000 body!

Bill Wadman recently wrote about this in a blog post titled Glass (part one). He introduces the subject by saying: Bill also goes on to discuss the benefits of prime lenses instead of zoom lenses.

Read Bill's article to see what else he has to say about choosing lenses.