Lens Review: Sigma 120-300 f/2.8 DG OS HSM A1

02 23 2014

The Sigma 120-300/2.8 lens I rented for the past week has been boxed up and is ready to be shipped back. It’s been a fun shooting with it, and I’m sad to see it go back.


  • Sharp, even wide open
  • Minimal vignetting wide open
  • Being able to shoot 300/2.8 without being locked into a prime lens is really handy during a shoot.
  • Being able to cover the entire 120-300 range at 2.8 is really, really handy.
  • Usable without a monopod (but barely)


  • Heavy. Very heavy. 1DX + this lens + 600EX-RT is almost 12 pounds.
  • Focusing is a little on the slow side. (It’s not THAT slow, but it’s not a true sports lens by any stretch.)
  • It’s not cheap. However, there’s no other lens like it, and it’s a lot cheaper than say, Canon’s 200-400/4.
  • Very conspicuous. I don’t think I’ve ever gotten this many comments about my lens before. Carrying the lens definitely makes you stand out.

Should You Buy It?

If you need a f/2.8 zoom lens that goes beyond 200mm, this is an excellent value. If you rarely need to shoot beyond 200mm at f/2.8, consider the Canon 70-200/2.8 instead.

Will I Buy It and Why?

Probably — there are many times when shooting cosplay and my kids that I want to go beyond 200mm and still have the bokeh from f/2.8.

New Laptop

02 12 2012

I frequently get asked “What laptop should I buy?” Everyone’s needs and budgets are different, so there’s no one correct answer for everyone, but I wanted to walk through my thought process in deciding my most recent laptop purchase.

The hard disk in my wife Caroline’s laptop died yesterday. It was an 8-year-old hand-me-down laptop (Dell Latitude D800), so instead of replacing the hard drive, we decided to buy her a new one.

Our requirements:

  • It has to have a 4 year life as a primary laptop. (In other words, it should be able to handle everything we throw at it for at least 4 years.) After that, we’ll continue to use it, but it may not be able to handle high-end games and applications.
  • 15″ screen, because a 17″ screen is too heavy and too hard for her to carry on an airplane, and a 14″ screen is too small.
  • It has to be able to handle the games that Caroline plays.
  • Total price must be under $2500.

What we chose:

  • Dell Latitude E6520, since it will work with our existing Dell E-series docking station, and because we’ve had good luck with Dell’s Latitude line.
  • Quad-core i7 processor. Nothing else is going to have the 4 year life we want.
  • 8GB RAM. Unless you have an extremely tight budget, there’s no point in getting any less.
  • nVidia NVS 4200M discrete graphics card. Required for Caroline’s gaming.
  • 128GB SSD. The performance difference between an SSD and a regular HDD for the boot drive is tremendous. If you want a fast computer, an SSD is a must.
  • Bluetooth module. This lets her hook up an external keyboard, mouse, headphones, etc, without cables or a proprietary dongle.
  • The E6520 has an integrated webcam and mike.
  • High-end integrated WiFi card. Since the laptop will be used in WiFi mode most of the time, having the strongest possible WiFi connection is a must.
  • 9-cell battery (the standard is 6 cell). The quad-core processor really needs this for halfway-decent battery life.
  • Standard DVD burner. This is becoming increasingly unnecessary; I wouldn’t be surprised if this was my last laptop purchase with an optical drive.
  • Windows 7 Ultimate with recovery media. Recovery media is important if your disk dies and you need to reinstall, or if you decide to replace the internal drive yourself.
  • MS Office Starter 2010. Caroline doesn’t need anything other than basic Word and Excel.
  • 3 year on-site service. We didn’t get any of the add-on “advanced” services, since I can do all my own software support and troubleshooting. We did get the accidental damage add-on, since we have two kids and will be traveling a lot. Also, the accidental damage add-on makes it harder for them to refuse warranty service on some random pretense.

Other people have different requirements and different budgets, so please don’t treat this as a recommendation of what anyone else should buy. However, it is a good example of how I go through the process of deciding what to buy, and hopefully will help other people decide what’s right for them.

ConDroyd, my new ALA 2011 schedule app for Android

01 03 2011

ConDroyd is a FREE Anime Los Angeles (ALA) 2011 schedule app for Android phones & tablets that I wrote. It includes the latest published schedule and all the cosplay gatherings posted on cosplay.com. It lets you star your must-attend events, and then you can filter to display just those events. You can also enable reminders for your starred events so you don’t miss them.

For more info, please go to http://www.condroyd.com/

If you’re coming to ALA and have an Android, please download my app, give it a try, and let me know what you think.

How to Choose a Digital Camera

02 10 2010

One of the most frequent photography-related questions I get is, “Which camera should I buy?” Given the sheer volume of digital camera models being introduced every year, and the mega-hype associated with every trivial feature, it’s not surprising people have a hard time choosing a camera model. When I get asked this question, I usually run down a quick checklist of questions (budget? SLR or P&S? etc.) with the person, and then make one or two recommendations based on my experience.

Apparently, the bloggers at Make The Photo get asked the same question a lot too, because they’ve put together a flowchart with the same type of questions I normally ask, along with their own recommendations for each category of photographer. Their flowchart is available at http://www.makethephoto.com/how-to-choose-a-digital-camera/.

I love this flow chart for several reasons:

  1. It uses roughly the same questions as I use, in the same order, so it matches how I decide which camera to recommend.
  2. It recommends the same cameras as I would in most situations.
  3. The flow chart is regularly updated as new cameras are introduced. The last update was a few days ago, when they added the newly-announced Canon T2i.

In other words, if you use this flow chart, you’ll get the same recommendations as if you’d asked me directly, assuming I was able to keep up with every new camera announcement. From now on, when someone asks me for a camera recommendation, I’ll first point them to the flow chart, and, if they have any questions, I can answer them. Yay for the Internet!

My Photo Processing Workflow

11 21 2009

I get asked every so often what my photo processing workflow is like, so I decided to post it here:

  1. I always shoot RAW. (Why? Disk space is cheap; ruining a great shot because of white balance issues is annoying.)
  2. When I arrive home with a new batch of photos, I copy them all to two places: my NAS (to back up my unedited photos) and my photo editing workstation (into a to-be-edited folder).
  3. My wife Caroline reviews the photos on the photo editing workstation using Canon’s Digital Photo Pro (DPP), marking the ones she does and doesn’t like.
  4. I review Caroline’s selections and occasionally make a few changes to the selections. In addition to some differences in taste, I will occasionally toss out photos because I don’t think they are salvageable. I also add in  photos similar to some of the already-selected photos because I plan on cropping or editing them differently. I will also sometimes switch out a photo for a very similar looking one for technical reasons — slightly better focus or exposure, or less noise. Having said all that, about 95% of the photos I post are the ones Caroline selected.
  5. I delete the rejected photos from my photo editing workstation. (Note that I still have all the unmodified photos on my NAS.)
  6. I edit the selected photos in DPP, and then export them as top-quality JPEGs.
  7. If needed, I edit the photos some more in Photoshop. (This is pretty rare.)
  8. Caroline reviews the edited photos and provides feedback. If needed I work with her to retouch the photos she has concerns about. Usually a few more photos get deleted at this point.
  9. I upload the photos to SmugMug.
  10. I move the edited RAW and JPG files to an edited folder on my NAS. The NAS now has every photo I took straight off my camera, an edited RAW file for photos I’ve posted, and all the JPGs that I’ve posted.
  11. The NAS is backed up regularly to two separate external drives, one of which is stored off-site.

(And before anyone says, “You should try Lightroom!”, I’ve tried Lightroom, and prefer DPP’s RAW processing.)

Every Software Change Has Risk

11 05 2009

Almost invariably at the end of a software project, someone will insist on fixing an annoying but non-critical bug. Perhaps the browser will freeze if you hit refresh 200 times in a row, or maybe button text overlaps when you get more than 20 incoming calls during an outgoing call. The cry will go out, “We should fix this bug! It’s a simple change! It couldn’t possibly break anything!” Sometimes this will come from marketing; other times the engineer for that component will want to make the change.

Looking at the proposed fix, the change will appear to be fool-proof. Perhaps a variable didn’t get initialized properly, or a resource had a typo, or someone forgot a break in a switch statement. You may say to yourself, “There’s no way something this simple could possibly break anything, so let’s do it!”

Before you agree to a claimed “zero-risk” change, read this true story from Raymond Chen at Microsoft. It demonstrates how every change has risk, sometimes in unusual and unexpected ways. During the middle of a project, there’s time to find and react to any unexpected side-effects from a change; at the end of a project, the side-effects may be serious enough that dealing with them will delay the software’s release. Do you want to be the one explaining to the CEO that the product can’t ship on time because a “zero-risk” cosmetic fix introduced a serious problem into the planned final build?

So avoid the temptation, and at the end of a project only fix bugs that actually prevent the product from shipping.

New Computer & Photo Status

10 26 2009

I was hoping to have the Dragon*Con Friday photos up by now, but for two reasons they’re not done yet:

  1. Friday was by far the biggest day for photos, so it’s taking longer than I expected
  2. I spent a large part of the weekend migrating to a new computer that I assembled myself.

My previous system was a 4-year-old WinXP dual-core AMD system that was really showing its age. The new system is much spiffier:

  • Intel Core i7-860 quad-core hyperthreaded processor
  • 8GB RAM
  • 160GB SSD for the OS
  • 1TB high-speed SATA drive for data
  • Blu-ray optical drive
  • Radeon 5870 graphics card
  • 750W power supply
  • Intel DP55SB motherboard
  • Antec Mini P180 case
  • Windows 7 Ultimate x64

Not surprisingly, the new system is very fast. Operations that took a second or two on the old system are now instananeous. Launching Photoshop CS4 used to be slow enough to grab a coffee; now it takes 3 seconds. This massive speed increase is making a big difference in my ability to edit photos (and Caroline’s ability to select photos) efficiently, so I’m hoping I will be able to get photos out quicker in the future. (When you’re going through 1000 photos, even one or two seconds per photo saved adds up quickly.)

Product Shortages and the Supply Chain

04 19 2009

Recently I decided to purchase a new camera, the Canon 5D Mark II. It has received excellent reviews from just about everyone who’s used it, and seemed like the appropriate upgrade from my Canon 40D. I quickly discovered that even though the camera has been out for over six months, it’s still very hard to find. Most major online sites list it on back-order, and Amazon.com doesn’t even sell it except through third-parties.

When there are shortages of consumer electronics product such as the 5DII or the Nintendo Wii for long periods of time, conspiracy theories are inevitable. Perhaps the manufacterer is deliberately keeping supplies low to maintain an image of popularity or exclusivity? Or perhaps there are quality control issues? While these are all possiblities, they’re not very likely. At Handspring and Palm, I saw first-hand how difficult it is to have the right amount of product available at all times, and some of the reasons why there can be long-lasting shortages of a consumer electronics product.

Before getting into specifics, it’s first important to note one thing: having too few of a product is much preferred over having too much. Of course, having exactly the right amount is ideal, but in the real world forecasts are always going to be slightly off, so it’s better to estimate low. Why? Because inventory is bad, especially in consumer electronics. Having a warehouse full of product that the company has already paid for but hasn’t sold is a drain on operating cash. It also puts pressure on the company to lower prices, reducing profits. Low inventory means stable pricing, solid margins, and strong cash flow. Shortages mean a company is making money, but could be making more. A glut can reduce prices to the point the company isn’t making any money.

So what would prevent a company from building enough of a product to meet demand? The obvious answer is of course  shortages of one or more parts. If your product has an LCD screen, and there’s a worldwide shortage of LCD controllers, you probably won’t be able to get enough LCD controllers to build the number of units your customers want. Worse, if you’re a small or medium company, the LCD controller manufacturers are likely going to favor their best (AKA biggest) customers, with any leftovers going to smaller companies. If you’re a big company, while the LCD controller manufacturers may be filling a larger percentage of your requests, because your orders are so big, a small percentage shortfall is still large in absolute numbers.

Some parts also have very long lead times, with six to nine month lead times not unheard of. Since Christmas stock is built in fall, by February or March you need to decide how much your customers will want in December. If you guess wrong, you’re either going to have a shortage or a glut. Manufacturing decisions that look dumb today may have been made 6 months ago, and may have seemed like a good idea at the time. Keep in mind that shortage is preferred over glut.

Even if with enough parts on hand, a manufacturer may be limited by their product assembly line capacity. It’s easy to say, “why don’t they just bring up another assembly line?”, but it’s not that simple. Bringing up an assembly line is a long-term investment that is very time consuming and expensive. If an assembly line is brought up and then idled a short time later, the company will lose a lot of money. Therefore, a company will need to be 100% sure demand will stay high enough to require the additional line. Again, shortage is preferred over glut.

Finally, an international company like Palm needs to decide where to send product after its been built. If every geographical region’s requests can’t be met due to a shortage, HQ needs to decide who gets priority. This decision can be made a variety of ways, including deciding which regions are most strategic, which regions are most profitable, or which retailers are screaming the loudest. In the case of the 5dII, the US dollar is pretty weak right now, leading me to speculate that Canon is allocating fewer units to the US because they are less profitable than units sold in Asia.

So while it’s possible a company is deliberately building too few devices, it’s much more likely that someone, somewhere in the supply chain, made a wrong decision based on available data a few months ago.

Source or Transport?

02 16 2009

I have read many blog posts and articles where the authors confuse energy sources with energy transports. Failing to make this distinction makes it impossible to discuss energy policy coherently, so I wanted to write a post about this topic.

An energy source is something occurring in nature from which humans have found a way to harness energy. Waterfalls, sunlight, petroleum, and plants all fall into this category. Frequently, though, energy sources are not in the same physical or temporal location where the energy is needed and cannot be easily transported, so an energy transport is required to move the energy. Examples of energy transports include electricity and hydrogen.

The easiest way to distinguish between an energy source and an energy transport is to compare energy in versus energy out. Petroleum products release more energy when used then it took to refine the petroleum, so it is an energy source. On the other hand, it takes more energy to produce hydrogen then what is released when it is used, so hydrogen is an energy transport. 

It’s not always clear whether something is an energy source or merely a transport. Ethanol has been touted as a “green” energy source, but by some peoples’ calculations it takes more energy to produce corn ethanol than what you get using it, making it an energy transport. You still need an energy source to produce the power required to make the corn ethanol.

It’s important to note that energy transports are not equally efficient. For example, high-voltage electrical lines lose a much smaller percentage of the power being transported compared to low-voltage lines, which is why high-voltage lines are used for long-distance energy transport. The less energy lost by an energy transport, the more efficient it is.

When looking at the energy efficiency of a device, measuring how efficiently it uses the energy in an energy transport is not helpful; instead, you need to look at how much energy is required to make the energy transport to begin with. For example, hydrogen-fuel cars do not actually run on hydrogen energy. The energy in the hydrogen used by the car was generated using an energy source like oil, coal, or solar. Therefore, to determine the true efficiency of a hydrogen car, you need to look at how much energy (oil, coal, solar) was required to produce the hydrogen. Sometimes there are multiple intermediary energy transports — coal generates electricity which is used to create hydrogen to run the car — so the question becomes, how many miles per poud of coal does your hydrogen car get?

When talking about alternative energy, it’s important to be clear whether you’re talking about better energy sources or better energy transports. While it’s important to use efficient and eco-friendly energy transports, if the energy being transported was generated by inefficient or dirty energy sources we’re not that much better off. For example, too many people claim that electric cars are more eco-friendly than gas-burning cars without stopping to consider how we will generate that electricity. Since a lot of our electricity is generated by burning coal, is switching cars from a petroleum-based energy source to a coal-based energy source really a good idea? Likewise, hydrogen is a relatively clean energy transport and may eventually be practical for powering cars, but what energy sources will we use to generate that hydrogen?

One of the reasons people focus on energy transports is that our options for energy sources are limited, and all of them have significant drawbacks:

  • Petroleum is considered “dirty”, and there’s a relatively limited supply pumped mainly by countries hostile to us.
  • Coal is considered even more “dirty” than petroleum, and there’s a limited supply too.
  • Most solar power plants require solar cells with all sorts of toxic chemicals that leach out into the ground. Solar is also very expensive and because of the inefficiency of today’s solar cells is limited to relatively small parts of the world.
  • Hydroelectric requires dams that cause ecological damage to fish and streams.
  • Natural gas has a very limited supply.
  • Nuclear generates toxic waste and requires a lot of overhead to safely run a generation plant.
  • Wind is limited to very few areas of the world and causes ecological damage to birds. Some recent studies have suggested it also modifies the surrounding climate by altering wind patterns.
  • Geothermal is also limited to very few areas of the world.

However, if we are serious about becoming more eco-friendly, we must start seriously discussing where we should be getting our energy from, instead of only discussing the best ways to get that energy into our cars, homes, and offices.

Public vs. Indexed

12 06 2008

It shouldn’t be surprising that advances in technology often outrun society’s ability to adapt to them. A good example is public records laws. When many public records laws were originally passed, searching through public records was difficult and time consuming. You (or someone you hired) had to go down to the courthouse and manually read through tons of documents. This effectively meant that public documents were really only available to people with a lot of time (or money, to pay for someone else’s time).

When those records were put online and indexed by search engines, the information contained in them became easily accessible to everyone. Want to know what your neighbor paid for this house? Google it. Want to know when your boss got married? Google it. Once people realized how public public records were, the amount of information made available was reduced to protect people’s privacy. In principle, that information had always been available; in practice, it was only made available in a usable format after it was indexed.

In fact, search engines have made it much easier to find all sorts of information about a person. Before Google, when you met someone at a convention, you couldn’t find out much about them afterwards unless they chose to share their personal contact info. Now, you could plug in the info from their badge into Google and (usually) find a wealth of info about them. Fanime has about 10,000 attendees; if only .1% of them are stalkers, that’s ten stalkers walking around Fanime.

However, right now, there is a good way to protect against this — don’t put a real name or any Internet aliases on your badge. For conventions that always print a real name, black it out with a marker. Without a search term, text-based indexes are useless . Stalkers could take a picture and post it on various forums, but that is hit-or-miss, doesn’t scale, and alerts the target that someone is stalking them.

This is a good way to protect yourself for now, but what happens when you can search by photo? Facial recognition has been around for a while, but it has always required tremendous computing power and was somewhat unreliable, In last year or so, Google rolled out facial recognition in a limited fashion for Picasa. This means the technology is getting easier and cheaper to deploy. In the future, what if Google developed an image-based index? In other words, what if you could point Google at a picture and ask for more pictures of the same person?

If that happened, anyone who has pictures of themselves posted online could be found with one photo. If a stalker took one picture of my daughter at the mall, without even knowing her name they could find all my photos of her, and probably eventually find her address and other info.

Of course, eventually, society will adapt. Google text-search encouraged people to make their blogs “friends-only”  and reduced the amount of information in public records. Some people always restricted their blog, but it didn’t become the norm until people realized how much info about themselves could be found through Google. Likewise, once people realized the impact of search by photo, most people would probably restrict photo access to friends/family.  But just as it’s pretty much impossible to suppress all text info about yourself online, it will be impossible to suppress all photos of yourself online, and we will all lose a little more privacy.