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16 Responses to "Full Frame vs. Crop Sensor"

1. | Reply Kevin Fox
   Posted 26 Feb 2008 at 3:18pm #
   

   But you can just crop down by hand, right? If your full-frame sensor has a high enough resolution, then there's no advantage to a cropped sensor.

   My Nikon D200 with a 70-200 2.8 lens can reach 5000mm, but with a resolution of about 600 pixels. 😉

2. | Reply ramanan
   Posted 26 Feb 2008 at 3:18pm #
   

   The cropped sensor isn't doing anything magical -- it certainly isn't going to turn your 200mm lens into a 320mm lens. The image the lens projects onto the sensor is being cropped. It isn't magnifying anything. If you want the same effect, just crop images from your 5D in Photoshop yourself.

3. | Reply Erik J. Barzeski
   Posted 26 Feb 2008 at 4:15pm #
   

   [quote comment="46208"]If your full-frame sensor has a high enough resolution, then there's no advantage to a cropped sensor.[/quote]

   Well, that's the thing, though. You have to crop a 12 MP image down to less than 5 MP to equal the view with the same lens through a 1.6x crop camera. Additionally, your depth of field changes.

   [quote comment="46209"]The image the lens projects onto the sensor is being cropped. It isn't magnifying anything. If you want the same effect, just crop images from your 5D in Photoshop yourself.[/quote]

   I never said it was magnifying anything, and in assuming that I'm the moron you've simply identified yourself as one in this instance - your snarky tone is particularly unnecessary.

   In other words, I understand how crop cameras work, and nothing I've written here says otherwise. A 200mm lens on a crop camera presents the field of view of a 320mm lens on a full-frame camera.

4. | Reply FT'e
   Posted 26 Feb 2008 at 4:17pm #
   

   I do own a 40D, with the excellent EF-S 10-22, 17-55/2.8 and 60/2.8 macro. I love that combination, it's by far the best photographic equipment I ever used.

   Once upon a time, long long ago, I was a big fan of the Minolta Dynax 9-series. Good, but not that good.

   Well, the real deal here comes with the lenses. The same combination for a full frame sensor would be much more costlier and a lot heavier. The 5D is pretty unique. Beside that camera, there is no full frame sensor camera of that size. They all use the pro form factor. Too big and heavy for me.

5. | Reply ramanan
   Posted 26 Feb 2008 at 5:23pm #
   

   Don't take it personally: I hate everyone with a 5D, not just you.

   If the feature you are after is the 1.6 crop, then why not get an older used body? You can probably get a 20D or 30D for far less than $1500. You can get old Rebels for a couple hundred bucks.

6. | Reply Erik J. Barzeski
   Posted 26 Feb 2008 at 5:57pm #
   

   [quote comment="46216"]Don't take it personally: I hate everyone with a 5D, not just you.[/quote]

   That's fine, but c'mon now, that's not what you said (or implied)…

   [quote comment="46216"]If the feature you are after is the 1.6 crop, then why not get an older used body? You can probably get a 20D or 30D for far less than $1500. You can get old Rebels for a couple hundred bucks.[/quote]

   I had an old rebel (two, actually) and sold them. The 350 and the 400. I'd definitely want the next step up for the second wheel if anything. An older model (20D/30D) isn't a bad idea, but at this point, even the $1000 is better spent elsewhere. Like on the MacBook Pro I ordered today. 🙂

7. | Reply Heinrich
   Posted 26 Feb 2008 at 6:28pm #
   

   The question do you prefer a full frame versus a "cropped" sensor is moot.

   If you define "Full Frame" as a sensor the size of 35 mm film, any manufacturer can make a sensor that size...and result in a three megapixel image.

   Just as digital photography is DIFFERENT from film photography with regard to image capture physics, some of the physical characteristics (sensor size = film size) are not true comparisons.

   Of course, with the marketing of "bigger megapixels equal better image" is not really true.

   Do you really want to pay $1500 for larger sensor, so you can shrink it down and post it on the web?

   I have blown up images taken with 2 megapixel Coolpix 2100 to 8.5 x 11, and the noise fields and the pixelation were visible if you got close up. But at normal viewing, the image looked fine.

   I guess what I am trying to say is the secret isn't in the sensor, it's in the equiptment that best suits what you trying to do at the time of the shot and in the photographer's skill (of which, I have none).

   P.S. I am super happy with my D300 and will be for YEARS to come. I have no desire for a D3.

8. | Reply Graham
   Posted 26 Feb 2008 at 7:16pm #
   

   What you're actually after is the denser pixels on the 40D's sensor (5.7um vs 8.2um), which allows it to resolve a bit more detail from the same lens. Nothing to do with the cropping.

   What do you mean by "your depth of field changes", btw?

9. | Reply Erik J. Barzeski
   Posted 26 Feb 2008 at 10:42pm #
   

   [quote comment="46219"]The question do you prefer a full frame versus a "cropped" sensor is moot.[/quote]

   I don't think so. There are tradeoffs in going with either of the two forms. And yes, I define "full frame" the same way everyone else in the industry does. The lenses we have still produce an image circle that covers (barely) a "full frame" sensor.

   [quote comment="46219"]Do you really want to pay $1500 for larger sensor, so you can shrink it down and post it on the web?[/quote]

   Let's not assume most of my photographs end up on the web. I still print more than I put on the web. And it's obviously not just the "larger sensor" that accounts for any differences in price. I get what you're saying… but tone it down just a little there Heinrich. 🙂

   [quote comment="46220"]What you're actually after is the denser pixels on the 40D's sensor (5.7um vs 8.2um), which allows it to resolve a bit more detail from the same lens. Nothing to do with the cropping.[/quote]

   No, that's not what I'm after. The 40D has a resolution of 10.1 MP. My 5D does 12.8. The 40D's pixels are much, much denser which really leads to increased noise - definitely something I wouldn't "be after."

   [quote comment="46220"]What do you mean by "your depth of field changes", btw?[/quote]

   I mean a 200mm lens, f/8, subject distance of 20 feet gives you 0.9 feet of DoF with a 40D but 1.42 feet with a 5D. Bump the 5D to 320mm (200 x 1.6), the "equivalent" focal length of the 40D, and you're down to 0.54 feet. Calculations done by the always handy DoF Calculator. So that's what I mean.

10. | Reply Bob Lee
    Posted 26 Feb 2008 at 11:39pm #
    

    I switched to the 5D because the crop factor seemed like a waste of glass. My lenses cost a lot more due in large part to their lack of edge distortion and vignetting, and I wanted to take advantage of that.

11. | Reply Graham
    Posted 27 Feb 2008 at 5:14am #
    

    But Erik, it's the denser pixels, and only the denser pixels, that allow the 1.6x crop without the reduction in pixel count you mentioned upthread. If you cropped images from a full-frame camera with the 40D's 5.7um pixel spacing (which works out as 25MP - there's a Sony DSLR that has that) you'd get exactly the same images as a 40D.

    So while there's a real compositional advantage to a crop sensor camera, the technical advantage you tout is purely about the 40D's pixel density, nothing to do with cropping. And as you say, there's a real trade-off in noise.

    Similarly, the DoF calculations demonstrate that a 200mm lens pretending to be a 320mm is much darker that the real thing. Your 200mm f/2.8 only gets as much light to the sensor as a 320mm f/4.5, because it doesn't have the big iris of a real 320mm f/2.8 lens.

    So yes, your original assertion that a crop sensor camera would give you "extra speed and reach" is not entirely thought through, to say the least.

12. | Reply Erik J. Barzeski
    Posted 27 Feb 2008 at 8:47am #
    

    [quote comment="46225"]But Erik, it's the denser pixels, and only the denser pixels, that allow the 1.6x crop without the reduction in pixel count you mentioned upthread.[/quote]

    Yes, I know… but smaller pixels (denser pixels) is rarely a good thing. I'm not sure what your point is. The added "reach" is due to cropping. The fact that they maintain 8 or 10 megapixels or more is due to the denser pixels. They're two related - but different - things.

    [quote comment="46225"]So yes, your original assertion that a crop sensor camera would give you "extra speed and reach" is not entirely thought through, to say the least.[/quote]

    Yes, it does. The "reach" still holds because even the Canon 1Ds Mark III is only 21.1 MP (to the 40D's 10.1 MP). And the "speed" still holds because even the 40D does 6.5 FPS while the 1Ds Mark III does 5 (and the 1D Mark III does 11). I wasn't using the term "speed" to mean amount of light. I tend to limit my use of "speed" in that definition to the lenses themselves. I was talking about the more literal speed - frames per second. Crop cameras tend to be faster in that regard.

13. | Reply Graham
    Posted 27 Feb 2008 at 12:08pm #
    

    See I'm confused - you seem to understand the science well enough to know that a 40D wouldn't be able to magic up a huge amount of extra performance out of the same lens, yet you started this thread by musing about spending $1500 on one in a heartbeat. Something does not compute.

14. | Reply Erik J. Barzeski
    Posted 27 Feb 2008 at 12:28pm #
    

    [quote comment="46231"]See I'm confused - you seem to understand the science well enough to know that a 40D wouldn't be able to magic up a huge amount of extra performance out of the same lens, yet you started this thread by musing about spending $1500 on one in a heartbeat. Something does not compute.[/quote]

    And I'm not sure what's confusing about "the extra (frames per second) speed and reach." Those are still true and still advantages of a cropped sensor camera.

15. | Reply Bernardo
    Posted 27 Jan 2009 at 1:17pm #
    

    Erik, I'm in your boat, although at the opposite end - I own a 40D and now want a FF body to take advantage of wide angle lenses and for higher IQ (due to less pixel density). But I definitely do want to keep the 40D for further reach and speed when it comes to sports or wildlife shooting... Tough choices. I'm probably going with a used 1Ds MK II as a FF body.

    I'm also in your boat as I seem to be the only one who understands (and supports) your logic about "greater reach". Seems to me like most people here simply can't create nor understand a coherent logical statement 🙂

1. Erik J. Barzeski
   Posted 27 Jan 2009 at 1:46pm #
   

   The original 5D can be had for $1250 (or less) these days… 😀