03-02-2020 09:56 AM
hi this is both a question and asking for recommendations. i have a 70D with a 50mm 1.4. i heard that the 70D is an APSC camera which means if i buy the wrong lens, the view could be narrower than intended.
do i have to specially look out for APSC lenses when i'm buying? if so, are there any letters or indicators that let me know that?
or better yet, can someone recommend me some great lenses i can look into?
i'm pretty new to cameras as a whole, so i apologize if this question is eye roll inducing.
03-02-2020 10:07 AM
Lenses are lenses and focal length is FL. Your 70D will use either "EF" or "EF-S" lenses. What is different is the angle of view. It is this AOV that you need to be aware of. On a FF DSLR the 50mm lens is considered normal. On a 70D it is more like the 35mm. Neither is actually normal as a factor of the approximate AOV of the human eye.
03-02-2020 10:18 AM
"...can someone recommend me some great lenses ..."
IMHO, either one of these two lenses is not only "great lenses" but mandatory if you want the best from your 70D. The EF-S 17-55mm f/2.8 IS USM Lens or the Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon. One of those is where you need to start. Each has an advantage over the other but either is very good and a great choice. The Canon is slightly longer at the tele side and the Siggy is slightly faster at wide open. Which is more important to you?
You have probably noticed the 50mil you have is somewhat limited to its usefulness. IIWY, I would not look at any more prime lenses, that is non-zoom lenses. Zoom lenses are far more friendly and give up little, if any, in IQ.
Next you need to look at one of the 70-200mm zooms for tele work. There is an f4 version and a faster f2.8 model. For UWA (ultra wide angle) I like the EF-S 10-22mm f/3.5-4.5 USM Lens.
03-02-2020 01:53 PM - edited 03-02-2020 01:56 PM
I believe the vast majoriy of lenses (or all?) denote the focal length in reference to the 35mm film/sensor size (aka full frame). So your 50mm lens on a full frame camera would have an approximate diagonal Field Of View (FOV) of around 46º.
You're correct in that when used on a camera with a smaller sensor, that the FOV will be narrower. By a factor of the crop value. Canon's APS-C cameras have a crop factor of 1.6. Thus, the FOV will be about 35º. To get a similar FOV on your camera, you'd use a 28mm lens. 50 mm divided by crop factor of 1.6 yields 31.25 mm. A prime 28mm is probably the closest you'll get to that 31mm figure.
Not to complicate things, but the crop factor affects other things as well. Here is one of the best explanations I've seen on the subject: Focusing on Depth of Field and Lens Equivalents
Regarding purchasing of lenses... There are lenses specifically made that only work with the smaller (crop) sensor Canon cameras. Canon calls these EF-S lenses. There are advantages in that they are typically less expensive, smaller and lighter than EF lenses. However, if you ever move to a full-frame Camera (e.g. EOS 6D, 5D, 1D), EF-S lenses won't work. So you may want to consider protecting your investment as needed.
Also, many of Canon's EF lenses are part of their L-series line. These often include weather-sealing, higher image quality, build-qualtity, etc. They are quite expensive, but well worth it, IMO.
Finally, unless you specifically need to have images that mimic a 50mm FOV on your camera, consider either a set of primes or a zoom or two to cover a range. The three most common ranges are wide angle, standard and telephoto.
Your 50mm is bordering on the telephoto side when used on an APS-C camera. As mentioned above a standard focal length for your camera is around 30mm. Wide angle I think would be around 20mm or less. Telephoto would be around 60mm or more.
03-02-2020 02:00 PM
Regarding primes vs. zooms... that is up to the original poster to make the determination based on what their vision is.
I personally use primes since my vision is often to capture as shallow DOF as possible and have the best possible low-light performance.
Both types of lenses have their advantages and disadvantages.
03-02-2020 04:41 PM
"I believe the vast majoriy of lenses (or all?) denote the focal length in reference to the 35mm film/sensor size (aka full frame)"
Wrong. The focal length is a physical measurement of the lens and has nothing to do with image format - a 35 mm lens for a full frame is still 35 mm for a crop frame. They might note the full frame equivalent, but that should be clearly marked. For example, my EF-S 60 mm macro would still be a 60mm lens if you could attach it to a Full Frame Camera.
Just to be clear, a 50mm lens on a crop frame camera provides a FOV similar to an 80 mm lens on Full Frame, i.e., a lens on a crop frame camera will change the FOV towards telephoto compared to the same focal length on a Full Frame camera.
03-02-2020 08:48 PM
Correct. I didn't mean to imply that the actual focal length would change. What I should have written is that you'll often see literature outline the 35mm equivalents.
03-03-2020 09:16 AM
I think it is time to forget about "35 mm equivalents" that ship sailed 20 years ago when digital eclipsed film. Now you could argue that we should talk about "22 mm equivalents" since smaller frames have a much larger share of the market!
03-03-2020 09:37 AM
"I ... use primes since my vision is often to capture as shallow DOF as possible..."
Not to pile on about an unclear post, but no matter whether the lens is a zomm or a prime the DOF is exactly the same at similar FL and aperture. If you have a 17-55mm zoom set at 50mm and the 50mm prime both at f4, the DOF will be essentially the same. A big reason I recommend the EF-S 17-55mm f/2.8 IS USM Lens is the wide constant aperture. Again duplicating the charismatics of the prime. Only at the f2 or f1.8, etc, from a prime would you see a shallower DOF at a given FL.
03-03-2020 10:04 AM - edited 03-03-2020 10:23 AM
I agree Ernie about primes and I assume rs-eos is referring to those cases where the primes do have a wider maximum aperture than readily available zoom lens, particularly as you move into the telephoto range. I use prime telephoto lens often for sports because an extra stop really helps sometimes on dark fields even with the ISO performance of current bodies. More importantly for sports, the better primes acquire focus a little faster than a similar focal length zoom and the extra stop allows the camera body/lens combo to focus even faster (relative to a zoom) when light conditions grow worse. But this performance comes at a big cost in terms of dollars and versatility and modern better zoom glass is so good that for most shooting situations it is the best choice.
Shooting a lot of high school sports with the typical poorly lit venues makes me an outlier in terms of which characteristics of lens performance are most important.
Yesterday I calibrated 5 different lens (400 F2.8, 300 F2.8, 200 F2, 70-200 F2.8, and 24-70 F2.8) to my three different 1DX series bodies so that I can safely switch a lens between them on the fly if needed. I am planning to use some soccer team practice sessions to try some different shooting setups and today I am going to try shooting scrimmage with a three camera setup using 400 and 200 primes along with a 70-200 zoom to see how I like coverage from a fairly static position near the goal area. But this setup means in addition to my game setup 1DX series bodies I will need to throw the 5DS R with a 24-70 2.8 on it into the bag to get bench and group shots when needed so by season start I will probably just go with a 400 F2.8, 70-200 F2.8, and 24-70 F2.8 three camera setup that will do it all. Most of the JV games early in the season occur after sundown so the F2 200 provides some advantage there which is why I want to try it during practice sessions that run after sundown.
My plans for getting a lot of photography testing in during pre-season practice were somewhat diminished yesterday when I got drafted as an assistant coach but that will probably be the most enjoyable unpaid job I have ever done It is a fun time to work with the team because the last of the kids I coached when they were little are now starting their freshman year so I get a few more years to work with them.
As a side benefit, the heavy primes keep me in shape (at least that is what I tell myself) Photo is from getting ready to start the calibration process yesterday. It took about an hour total and none of the lens required more than a minor offset with most being dead on without adjustment.