Used Camera Database Blog

You may have noticed that there’s a few links in the upper right hand corner of the Lens Database pages relating to registering and logging in.  I think it is time we explained why the site accepts logins and requires registration for a number of tasks.

The general vision of the site is a collaborative place where camera hardware enthousiasts can share information and compile a large knowledge base of cameras, lenses, and accessories.  Well, a major part of that is collaboration, and the ability for anyone to edit information, add links, and score lenses.  Of course, this requires a certain level of trust that the users will not abuse or vandalize the database.  The easiest way to do that is to require registration before a user can modify the database.  This at least lets us track who is vandalizing the database and stop them before any real damage is done.

There are other advantages too: linking specific users to site information allows special features such as customized price displays, automatic tracking of prices on specific items, etc.  Furthermore, it provides a method to track reviews and comments and give rewards where rewards are due (more on that later!).

So, with that in mind, we urge you to register.  It is very easy, only requires your name, e-mail, and country (plus a password of your choice that is not visible to anyone else!), and lets you access all features of the database.  And we promise, the number of registered features for the database will grow quickly!

Also, we promise that you will never receive any unsolicited spam mail (infrequence announcements about UCDB excluded) and your name and e-mail will NEVER be sold or given to any other third party!

If you have any questions, let us know!

This is the first, short introduction to searching for lenses on eBay.  I can (and will) go into a lot more detail later, but it is important to start with the basics.

First, and foremost, I’ve found that manipulating search text is the best way to search.  Yes, there are a lot of other features for searching on eBay, such as searching categories and things like that, but there are many sellers that do not use categories correctly and often you’ll miss some listings that way.  The best way to get focused results is with a focused search string.  And the best way to get a focused search string is to figure out eBay’s logic, which isn’t that simple!

Of course, the best way to learn how to use search strings is to experiment.  So, go ahead and open up a window (or tab) to eBay.  Or, feel free to use the Search Page I created at UCDB to provide a fast way to experiment with searches (and to make it easier for me to show you the searches).

To give an example, let’s suppose we are looking for the original Canon EF 50mm f/1.8.  Specifically, that is version I, the one with the metal mount that goes for a higher price.  Typically, you should start off with a minimal search, since anything you list in the search space MUST be matched in the search results.  This means, if you specify a word that isn’t included in the listing you want, you’ll never see that listing!.  For the 50mm 1.8 the name is already pretty minimal, but you can quickly get into trouble searching for the Tamron AF18-200mm f/3.5-6.3 XR Di-II LD Asph. (IF) using the full text!

Let me say that point again, because it is important:

AND: The default for an eBay search is to match all the keywords you specify, an AND operation.  Order doesn’t usually matter though.

So, let’s start with just searching for ‘canon 50mm’.  It will return a ton of results (799 in my case), but that is ok — we didn’t specify the aperture.  And again, we’d rather see too many results than miss a good deal, so start small.  Also, note that ‘lens’ was omitted from the search.  Some people won’t put it in the title, so we’ll miss those listings.  Many people misspell ‘lens’ as ‘lense’, but believe it or not eBay catches that and converts it in the search!  (try it — both return the exact same results!)

The next step is to adjust the search to add the aperture, or search with ‘canon 50mm f/1.8′.   This knocks the results down to a more manageable 193 items, but we’re actually missing some.  I’ll go into more details on how eBay parses the search string in a future post, but the main thing is that eBay treats ‘f/1.8′ as essentially two keywords: ‘f’ and ‘1.8′, and only match items with both in the name.  But, it will not catch people who list the aperture as ‘1:1.8′, ‘f1.8′, etc.  Most sellers are savvy enough to include multiple keywords, but some are not.  That’s actually really good for us though, because if we spot listings no one else does, then we can sometimes save some money.  But how can we do an OR operation?  After all, we want to find the listings that use ‘f/1.8′ or ‘f1.8′ or ‘1.8′?

eBay’s construction for an OR operation is parenthesis.  Anything included between parenthesis and separated with commas is treated as an OR operation — at least one of those search keys must be included for a listing to be returned.  In this case, we can increase the number of hits (in a high quality way — we’ll never see the 50 f/1.4 or 50 f/1.0) by adding an OR on the aperture and focus specifiers to get ‘canon (50, 50mm) (f/1.8, f1.8, 1.8)’, resulting in 363 hits.  Yes, adding in coverage of other formats for aperture (and focus — did you catch what we did and why?) can almost double the number of auctions found.  In fact, we might get listings that many other buyers do not see, which can actually save us money!

OR: Specify an OR operation by using a comma separated list of keywords inside parentheses.

But, you’ll notice that many of the hits are not relevant for us.  They’ll be on hoods for the 50mm f/1.8, or the FD version of the lens.  Some of that we can alleviate by being more specific, i.e. adding the mount, EF, as in ‘canon EF (50, 50mm) (f/1.8, f1.8, 1.8)’ (167 listings) or better yet ‘canon (EF, EOS) (50, 50mm) (f/1.8, f1.8, 1.8)’ (171 listings).  But the real problem is that we’re matching many titles we do not want to match, such as FD lenses or lens hoods.  Well, eBay has an option to exclude items with certain keywords too: a simple hyphen, or minus sign.

EXCLUDE: Any keyword preceeded by a minus sign (‘-’) will cause listings with that keyword to not be returned.

For example, to get rid of the pesky hood listings, use ‘canon (EF, EOS) (50, 50mm) (f/1.8, f1.8, 1.8) -hood’ (100 listings).  Of course, that still has a bunch of stuff, including a lot of version II lenses, so my final search term is ‘canon (EF, EOS) (50, 50mm) (f/1.8, f1.8, 1.8) -fd -ii -mkii -hood’.  See if you can identify why I excluded each item.  The end result is a search that returns 31 very focused listings.  Sure, some of them may be mislabeled, but at least the number is manageable and we know that we haven’t missed and relevant listings.

Again, the power of a well-tuned search cannot be understated.  It can help you see the listings you want to see and avoid dealing with the listings you don’t need to see.  And, the best way to learn is… Experiment!

And remember — the Lens Database currently has over 200 Canon EOS lenses, each with tuned searches.  Feel free to steal our search strings as a starting point!

First round of Tamron lenses added, along with a number of fixes on eBay listings for Sigma and Tamron.  Prices should start trickling in during the next week!

Stayed up way later than I expected, but it is nice to have the big three makers for EOS mounts set up.

It also made apparent to me the utility of a database of lens name terms, acronyms, and numbers.  Hopefully I’ll set that up in the next week or so.

I was going to write up a post about eBay searching but I think I’ll postpone it. I’d rather get an initial pass of Sigma and Tamron (EF and EF-S mount) lenses up on the site.

With luck, I should get the kinks out and the lenses posted within an hour.

Some notes on Sigma lenses:

• I’m only going for the more modern lenses on this first pass.  Sigma is notorious for putting out tons of versions of lenses, and as yet, I don’t know how to keep track of them.  So I’ll just try to get up the DC and DG lenses on this first pass, then work backwards in time (to DL lenses, for example).
• The inconsistency in lens names is scary.  Different orders, many sites include ‘aspherical’ in the name.  But, Sigma’s website doesn’t, so that’s what I’ll go with on lens names.  It can always be changed later.

(Later)  Yikes.  That was more trouble than I thought it’d be.  But Sigma lenses are now up and (semi) functional.

Let’s face it…  understanding lens names is difficult at best and downright frustrating sometimes.

For instance, take the new Sigma APO 70-200mm F2.8 II EX DG MACRO HSM. EX?  DG? HSM? APO?  What the heck does all that mean? And how does it differ from the Canon Canon EF 70-200mm f/2.8 L IS USM?  What about the Canon EF 70-200mm f/4 L USM?

Ultimately, lens naming comes down to one basic idea:

Every letter counts.

Manufacturers try to cram a lot of information into lens names and that can make them very confusing.  The key is to realize that small distinctions and differences in name can mean a very different lens.  Not always, but sometimes.

The first method of distinguishing lenses is focal lengths, an optical feature of the lens that determines how the world will look through the viewfinder.  Anyone familiar with photography knows that longer focal lengths means more ‘zoom’.  More recently, lens makers have been specifically choosing focal lengths to help distinguish lenses.  For instance, the Canon EF 100mm f/2.8 USM Macro, Sigma 105mm F2.8 EX DG MACRO, and Tamron SP AF90mm F/2.8 Di 1:1 Macro all are meant for the same purpose (medium telephoto 1:1 macro lens), but have been given slightly different focal lengths to prevent confusion.

The second major way to tell lenses apart is aperture, or the amount of light a lens allows onto the film or sensor.  Typically, larger apertures (smaller numbers) mean a more expensive and high quality lens.  For instance, the Canon EF 50mm f/1.8 II costs about $85 on the used market while the Canon EF 50mm f/1 L USM is rare and sought after and goes for more than $4000!  Two lenses with the same focal length(s) and different apertures are going to be very different lenses.

Furthermore, lens makers usually have a ‘pro’ line that has better optical and build quality and fetches higher prices.  Canon has the “L” series, Sigma has the “EX” series, Tokina has the “Pro” series, etc.  Usually, these designations means something specific about the lens; for instance, the Canon “L” designation means that the lens has aspherical elements, but often the “L” lenses include other premium features like USM, weather sealing, etc.

Other letters in the names of the lens can designate specific mounts/compatibility (DI, DI-II, EF, EF-S, FD, etc.), autofocus motors (HSM, USM, AF-S, etc.), image stabilization (IS, OS, VC, VR), focus construction (IF, RF), optical elements (APO, DO, ED, UD, ED, SLD, etc.), coatings (S.C. and S.S.C. for those Canon FD enthousiasts), and even the number of optical elements (early Nikkon lenses had a dash and a letter (see table) that denoted the number of optical elements).  It pays to pay attention to the specifics, because typically a little difference in letters can either mean a different lens or a mistake when listing the lens model.  This can mean a huge difference in value, and you don’t want to be on the wrong end of an eBay listing mistake!

Finally, it should be noted that some manufacturers release different versions of the same lens and designate the difference with roman numerals, sometimes preceded by Mk or Mark.  For instance, the Canon EF 28-80mm f/3.5-5.6 V USM is the last lens of somewhere between 6 and 8 versions!  Sometimes the new version is better and fixes problems with the previous version; sometimes the new version is worse that its predecessor.  For instance, the Canon EF 50mm f/1.8 I sells for 60% more than the Canon EF 50mm f/1.8 II because the first version has a metal mount and sturdier construction than the second version.  Typically, budget lenses tend to have more versions because sales volume is larger and lens makers are constantly striving to reduce costs.  So, it pays to be aware of differences in versions!

Your best defense when looking for a used lens is to be aware of what versions exists, what the differences are, what typical prices are, and what they look like.  Especially what they look like.  I have gotten some deals on lenses since they were mis-listed and the seller did not know what they were selling, but I’ve also seen budget lenses mistakenly listed as more expensive lenses!

The UCDB Lens Database is a great way to compare lens prices and versions.  Currently, there are 135 lenses in the database, every single Canon-made EF and EF-S lens I could find.  So if you’d like to compare versions and prices, the database is a great place to start!

This would be a good time to discuss what is planned for the near future at the Used Camera Database.

1. Top priority for the next week is getting the third party brands for the Canon EOS system into the database (i.e. Sigma, Tamron, Tokina, etc.).  I’d also like to get the FD and FL lenses listed (at least some of them) but that is lower priority for now.
2. Polishing existing entries will continue to be a priority, including refining search terms, fixing duplicates and missing lenses, etc.  The goal is to get all EOS lenses listed well, test other features (listed below), then add Nikon, Minolta, Sony, and other lenses.
3. Linking.  One of the big selling points of this database, at least for me, is the ability to have every lens in the database linked to the relevant reviews, comparisons, manuals, datasheets, etc. on the web.  The goal is to make it that much easier to determine which lens you want, then find out about it and access the wealth of information out there without spending hours in Google.  I hope to have linking done in the next couple of weeks, and to spark it off I’ll have a linking contest with a (meager) cash prize.
4. Comments and ratings.  After linking, I want to get a comment and rating system in.  Ratings, in particular, are very useful for me when I compare lenses, and I’d like to get that here.
5. Aesthetics.  Usability is way more important that how nice the site looks, but I do have plans to ‘pretty’ it up.  Most likely this will be a larger update in a few months, depending on how other things go.

Also, in terms of the blog, I’m going to make a more concerted effort to add content.  Specifically, over the next week or two, I’m going to post regularly about the philosophy of the site and things I’ve learned while make it.  In particular, I’ve learned a ton about classifying and searching for lenses on eBay that I’d like to share.  These posts will generally be short, but my goal is to get out about one a day.  So check back often (or subscribe using the links at right)!

So, stay tuned!  If you have any suggestions, let me know!

I know very few are watching this space, if any, but I’m ok with that for now.  I’m still trying to add more features and tweak things in the site.  Specifically, in the last week, I’ve:

• Added better search support.
• Added popularity and stats measures (to both make my life easier and expose some nice information for the users).
• Added some admin pages to aid me (and others) in managing the site.
• Added better logic and mechanisms for the price tracker.  It now has data out for about a week, and things are getting interesting.
• Added a number of Canon EOS lenses (I still have many more to add).
• Fixed many, many bugs!

I’m going to keep tweaking and adding more lenses, and in a week or two I’ll start letting people know about the site.  Until, then, I’m happy to keep traffic light because I often change things!