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Do new photographers really need to learn crop factor?

Discussion in 'General Discussion' started by hotrod4x5, Nov 6, 2018.

  1. Yes

    16 vote(s)
  2. No

    5 vote(s)
  3. Maybe, but later on, when they are more advanced.

    5 vote(s)
  1. I teach beginning digital photography at a junior college. I got a lot of my lecture materials from the department head when I was first hired. I have modified them over the years and added my own. I still teach these new photographers about crop factor, image circle sizes, "full frame" and so on.

    But I began to wonder recently if this is even necessary? If you originally shot with film, it was important to understand that a 24 MM lens on early DSLR would not give me the same field of view as I was used to. So the crop factor and doing the conversion was important to understand what I would get and what lens I needed to buy. Why did I need that 12-24? Oh! The crop factor. Yes.

    But nowadays, no one is coming from film, and no one (well, darn near no one) is buying a "full frame" camera first.

    I teach that 40-50mm lenses are about "normal." I teach that very near the beginning and don't get into crop factor until later, when my students have a better feel for their cameras. They learn that 28 and lower are wide angle lenses. 24-28 are moderately wide, 10-20 are very wide. They don't have any frame of reference in their minds to need to know that a 10mm lens "looks" like what a 15 mm lens gives on full frame. That point is lost on them.

    Anyway, this is a very long explanation to ask: Do new photographers really need to understand crop factor? Why or why not?
    • Agree Agree x 1
  2. I don't really see the point either. Most of these students will be using the lens appropriate for their sensor. The who crop factor discussion is moot at that point. Time is better spent discussing how 50mm is approximately our "normal" and then giving real world illustrations of the effects we see at different focal lengths.

    My daughter just had her yearbook photo taken by a local "pro" photographer. My wife was unhappy with the photo but couldn't figure out why. One look and I recognized wide angle distortion. Showed my wife the following illustration which was very illustrative.
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    • Like Like x 2
    • Agree Agree x 2
  3. Butlerkid

    Butlerkid Cafe Ambassador Moderator

    Apr 8, 2008
    Rutledge, Tennessee
    Before students get excited and start wanting/buying a camera and lenses, I think you should cover briefly the types of sensors (full frame, micro 4/3s, crop, etc) and discuss the pros and con's of each relative to lenses and what subjects tend to be best for each. A brief over view and be done with it.
    • Agree Agree x 1
  4. Replytoken


    Jan 12, 2018
    Puget Sound
    Looking at Mitch's illustration leads me to believe that what needs to be taught is not just crop factor, but the impact of distance to subject and how it relates to focal length and sensor size. I am a big believer of the basics, whether they are taught at the beginning or later when students have a bit under their belt.

    • Like Like x 1
    • Agree Agree x 1
  5. There are a lot of myths associated with crop factor/sensor size. Dispelling them early on will be doing new photographers a favor.
    • Like Like x 1
  6. Thank you for the replies thus far. All very good points.
  7. All knowledge is good. How it is presented and applied is important. If you feel that beginning photographers are confused more by introducing the "crop factor" concept early into the learning process, then delay it further into the curriculum or into the more advanced classes.

    The fact that we do have 135, APS-C and m43 sensor sizes in our current ecosystem, the ability to use adapted lenses still makes the concept important to know and understand, especially once someone gets into the need/desire to use a specific tool for the job.

    To be honest, I teach as well, and "crop factor" and sensor size are a lot easier for the students I've had to comprehend than exposure triangle type stuff and depth of field.
    I do get a lot of questions about what cameras to buy from them as well, and the fields of view turns out to be a lot more important than most people realize. Especially when we are talking about people starting out.

    This is where the difference in say a 20mm on a 135 size sensor is a huge difference when compared to that same lens on m43, where it is a 40mm field of view.

    I find that most appreciate a solid foundation on the basics first, an idea of what other topics they may want to know down the road and to explore them later on in detail.
    • Like Like x 2
    • Agree Agree x 2
  8. I think crop factor is an important concept to know. Considering APS-C and other smaller sensor form factors are now the majority when it comes to digital cameras. A visual chart to illustrate that fact should probably be shown first in order to understand FOV. Either that or require everyone to shoot FF! :D 
    Last edited: Nov 6, 2018
  9. tenplanescrashing


    Oct 15, 2008
    It's worth mentioning that it exists but I wouldn't dedicate much time to it until they've gotten the hang of photography in general first.
  10. bmell


    Feb 11, 2009
    Like you, I have taught as an adjunct photo professor for six years now and I do no teach it as crop factor per se, but talk about format and I bring in my d300, D810, then I bring in my old 645 and RB67 medium formats along with an old 4x5 studio camera and discuss the differences between the cameras and how focal length is figured on different "film" sizes. I think it is important to understand this if they continue beyond the basic 100 level class in the future. The 4x5 and RB also shows then how the image is upside down and how a pentaprism corrects that.
    • Like Like x 2
  11. BrianVS


    Mar 15, 2017
    A 40mm~50mm lens is "about" normal on a full-frame camera. It is a telephoto on a Nikon 1. 28 is a wide on a full-frame and DX camera, it is a normal lens on a u43 and a telephoto on a Nikon 1. So- focal length alone cannot be used to determine of a lens is a wide-angle, normal, or telephoto. It is all relative to the size of the image circle captured by the sensor, and that for all intents and purposes is "crop Factor".
  12. I have to go along with it being important. I agree that there is and can be a lot of confusion when you start getting into the impact it has on DOF. But I think a basic explanation with a deliberate statement about NOT going down that wormhole would probably be enough at the beginning.
  13. BrianVS


    Mar 15, 2017
    As a Teenager back in the early 70s I shot 35mm, 16mm Sub-Mini, Super-8 Movie, and Regular-8 movie. The Books simplified it all: The normal lens was about the diagonal of the frame. Take the Focal Length of the lens, Divide by the Diagonal of the frame- you have a relative magnification. A 45mm lens is "normal" for a full-frame, 24x36, 35mm film camera. A 25mm lens is normal for the 14mmx21mm format on the 35mm film Tessina. All this assumes the image circle of the lens is big enough to fill the frame. I'm not sure why anyone would compare one format with another, such as DX with FX. Compare the focal length of the lens with the size of the sensor is self-contained, and does not require a history lesson on "full-Frame" being 24x36.
  14. It's really pretty basic. Could probably be explained in a few minutes.
    • Agree Agree x 1
  15. One tool I've used for this is getting some framing mattes and placing them over a print. That helps explain it...or go into Photoshop and add yellow boxes over an image, representing the sensor size. That usually gets the point across rather quickly.
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  16. If they have difficulty with the concept of crop factor, they may have difficulty with some of the very basic concepts of photography. That's what smart phones are for ;) .
    • Winner Winner x 1
  17. I am not sure how much technical teaching is needed for beginners these days.

    Many really good photographers have taken great photos without paying any attention to focal length numbers and only paying attention to light, subject and how far they were from the subject and zooming enough to fill enough of the frame.

    A lot of them blissfully go about their way making images that put mine to shame :confused:  Maybe because they are concentrating on what they want to show and not how much they know....
    • Like Like x 1
  18. West


    Jan 2, 2012
    Vancouver BC
    Kind of like: This is how the combustion engine works, but you will never lift the hood.
    • Like Like x 1
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