The Canon 100-400mm L IS II zoom lens is perhaps the best lens I ever put on the front end of a Canon camera. Let's look at how it performs for Astrophotography.
Introduction
The Canon 100-400mm L IS II zoom lens is perhaps the best lens I ever put on the front end of a Canon camera. I plan on using it to replace some of my more traditional camera lenses, not just astrophotography ones. It focuses close enough to replace a macro lens and a 70-200mm zoom lens. You lose a little on the close side, but 70mm vs 100mm isn't that much and I can zoom with my feet. Plus the reach at the 400mm end is substantial, and is well worth the slight loss of the 70-100mm range.
Key Specifications
- Brand & Model: Canon 100-400mm L IS II f/4.5-5.6
- Type: Telephoto Zoom Lens
- Price Range: US$1000+ on eBay
- Key Features:
- Incredible versatility
- Flourite lens element for clarity
- Canon's best Image Stabilization
- Best For: Wildlife, portraits (yes, portraits) and Astrophotography
Design & Build Quality
- One of Canon's best lenses ever; full stop
- 57 oz. (1,620 g) with tripod foot
- 3.7" (94 mm) diameter x 7.6" (193 mm), when set to 100m (longer at 400mm)
- Fully metal construction with really heavy pieces of glass
- Did I mention that it's built like a tank?
Performance & Features
It's ultra-sharp, has a fluorite element, focuses incredibly fast (more so if you use the limiter switch), and auto-focus works with Canon Extenders. As if that isn't enough, it has one of Canon's best Image Stabilization setups which can easily help you get 4 or even 5 stops faster by eliminating camera shake. That means instead of being an f/5.6 at 400mm, it's really more like a 400m/f2.8 or better. Set your camera to ISO 400 and you can hand-hold this baby all day long. Or at least, until its 3.5 pounds makes your arms hurt.
One of Canon's best lenses ever; full stop.
I count myself lucky that I was able to secure one used in pristine condition for a great price. You may have to hunt for yours, since they are so fabulous that they rarely show up on the used market without commanding premium prices. But if you are as lucky as I was, you'll want to aim it at the stars almost as much as you'll want to take wildlife, landscape, and portrait photos in daylight. On an APS-C crop sensor camera like my Canon 450D or Canon 80D, it has almost the same reach as my main SV503 100mm/f7 imaging rig. More on why that's important later.
Ease of Use
- As mentioned, it's not light. You can handhold this for wildlife or other terrestrial work (especially with 4-5 stops of Image Stabilization) but get a tripod for astro imaging.
- You need to read the manual to understand the Image Stabilization settings, but they're straightforward enough. Everything else is pretty obvious and it's easy to hold.
- It's a giant point-and-shoot lens if you have a Canon camera (or an adapter). If you can find one and afford it, you should own one. It's that simple.
Pros & Cons
Pros
- Versatility
- Construction quality
- Replaces a lot of other equipment
Cons
- Weight
- Cost
- Availability
Who Should Buy This?
- Ideal for anyone with a Canon camera, whether film, DSLR, or Mirrorless
- Best suited for wildlife, portrait, wedding, sports, and astrophotography
Final Verdict
In short, this is an incredible lens for any kind of photography that you might use it for.
Here's a comparison from Astronomy Tools in Imaging Mode. If you don't know about this web site, you should bookmark it now. The field of view calculator lets you compare different scopes, cameras, barlows, and other items to see how it will effect your shot on solar system objects, Messier objects, and basically anything in the sky. Since it's a web page, you can run it from anywhere you have a network connection. Here's what it shows the FoV would be for my normal AP rig, taking pics of the Moon. This is a 102mm/f7 scope with an ASI2600 camera dedicated astro camera on it and a 0.8x flattener/reducer.
Now compare this to my Canon 100-400mm zoom on the front of a Canon 80D with no other optics:
Yes, they're not quite the same, but consider that, for the astro-rig, I have to turn on the mount, polar align it, start it tracking, set up guiding, and do everything with a heavy, equatorial, semi-permanent rig if I go with the first option. With the Canon, I can just pick it up, hand-hold it while I aim it at the Moon, and get a picture like this:
Imagine how much better it would be if I actually put it on a tripod, focused properly, and used a cable release? This is the ideal portable astrophotography rig! Plus, if I need to switch to something more wide-field, I can pop off the 100mm-400mm zoom and put on an 85mm or a 24mm or even a 10mm and capture almost the entire visible sky. Conversely, throw on a Canon 2X Extender, and now it's a 200-800mm lens (f/11 at 800mm). This is comparable to a lot of apochromatic telescopes! Since the camera, lens, and extender all weigh about six pounds total, that means I can use one of my Star Trackers instead of a big mount, and suddenly this thing becomes a nice portable rig.
More to come as I explore this lens further, but I'm very happy to have been able to secure it as part of my collection!
Where to Buy
- Good luck. I acutally found mine at Goodwill and bought it on sight without testing it. It was in pristine condition and it was "cheap." I got lucky. Maybe you will, too.
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FAQs
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Q: Will it work with my camera?
A: It will if your camera is a Canon EOS camera made since 1987. That includes film, DSLR, and mirrorless. It will also work with anything that fits a Canon EOS lens, so if you have a dedicated astro camera with an adapter, you're in luck. -
Q: Why is it good for portraits?
A: The background is very soft, with great bokeh and the 400mm end gives even softer backgrounds than a 200mm f/2.8. Look at the pros doing headshots in the field and you'll see 300mm or 400mm lenses on their rigs. -
Q: What else should I know about this lens?
A: In short, this is an incredible lens.