A Long Post on Lenses

   23 January 2006, early afternoon

I have owned my trusty Pentax K1000 since the end of high-school. In that time, I have bought two lenses for the camera. The first was a Pentax SMC 50mm f/1.8 lens, which I bought when I bought the camera body. The second lens replaced the first, and was a Pentax SMC 50mm f/1.4 lens, which I bought when I threw my camera and it landed lens-side down1. I like Prime Lenses.

I suppose my opinion on primes is just a matter of taste, but there are a few reasons primes almost always win over zoom lenses. Primes almost always produce sharper, nicer looking images. This is probably because they have fewer elements, and light needs to do less work to get on the film. (I haven’t used expensive zoom lenses, which might make this first point moot.) Prime lenses are always faster. I don’t think I’ve ever seen a f/1.4 zoom lens. An f/2.8, which would be considered fast for a zoom lens, probably will cost you well over a thousand dollars. Primes at f/1.4, f/1.8, f/2 are both common and cheap. Which brings me to my last point: most good prime lenses are usually a lot cheaper than good zoom lenses. (Wide-angle prime lenses are more challenging to build, and this is reflected in their price.) My first Pentax lens was $50 if I recall correctly. I got the second for free when I bought my brother a Ricoh SLR.

My Pentax lenses are both manual-focus lenses. 50mm manual-focus lenses are one of the easiest types of lenses to manufacture, or so I have been told. This is probably why they were both so cheap. (I will admit they are also probably not the greatest lenses in the world in terms of optical quality.) Unfortunately, it’s very hard to find manual focus lenses that work on newer camera bodies that expect auto-focus lenses. Most Camera companies don’t make pure-manual lenses anymore. (The view finders in most digital SLRs are so horrible when compared to film SLRs that you probably don’t want to both trying to focus manually with them anyway.) So, the age of really cheap prime lenses has probably come and gone.

I’m looking to get a new lens for my new SLR, the Digital Rebel XT. The cheapest prime available for my Digital Rebel is the Canon 50mm f/1.8 II, which is about $70 USD. And that is for a lens that feels like a toy2. That said, it apparently takes excellent pictures. The field of view on that lens is comparable to an 80mm lens on my Pentax, making it more of a medium-telephoto lens. I don’t know how useful this would be in indoors, in close-quarters, which is where I like to take a lot of my photographs.

To get the field of view equivalent to a 50mm lens on my Pentax, I would need to get a 30mm lens. There are a few choices, though I’m not sure there is a clear winner. Sigma makes a 30mm f/1.4 lens, but it is a digital only lens. It apparently also suffers from some vignetting at the corners. It’s also around $400 USD—damn. Canon makes a few lens that are that focal length, but slower. They are all around $200-$300 USD, which also doesn’t seem like that great a deal.

I’m thinking hard about what lens to get. I’m also thinking hard about whether I should get a lens at all, since I have probably spent more than I should in the past month.

1 The Pentax K1000 is a rugged sonuvabitch. Even the lens I destroyed didn’t shatter or break, I just jarred it enough that the focusing ring wouldn’t turn anymore; manual-focus lenses are built like bricks.

2 There is also a $320 USD Canon 50mm f/1.4 USM lens, which is better built, has a quieter/faster auto-focus, and a bigger manual focus dial you can use even while in auto-focus mode.



  1. I’ve noticed recently that since I have decided the Sigma 30mm is where I want to go next, I’ve been really reluctant to pick up my camera at all. I’ve been using the 17-85mm f4.0 lens that I got with my 20D pretty much exclusively for the last (over a) year. When I got my LensBaby 2.0 a few months ago, I realized that the greater aperture was really something that would dramatically change how I take pictures, especially considering that I pretty much always want to take pictures in low light.

    My stop gap measure of late has been to unlock ISO 3200 on my 20D and then shoot mostly in black and white (where the increased noise actually looks kind of cool). In a few weeks we may be getting a bonus at work, plus my tax return should be coming in around the same time, and I think that’s when I’ll be able to get the Sigma (I was also looking at the 50mm lenses but decided I want the 50mm “look”, not the 80mm field of view) and finally be really satisfied.

  2. I’m actually leaning towards the D50 again… I really like the 350D’s sensor… but Nikon’s just so much more versatile when it comes to lenses.

    I’ll probably get the D50 with the 18-55mm kit… but I really wouldn’t mind getting the Nikkor 28mm f2.8D as well… Fast and Sharp.

    Have u seen the new 18-200mm Nikkor? http://www.kenrockwell.com/nikon/18200.htm

    The relatively low price of this thing really surprised me…

  3. I know that the kit lens on the Nikon is supposed to be quite good, much nicer than the one that comes with the Digital Rebels. I think feature-wise it might be lacking. If you already have some Nikon lenses (that are good) it is probably worth sticking with the Nikon.

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