7D and non-L primes.

Discussion in 'Digital Photography' started by MattSepeta, May 27, 2010.

  1. MattSepeta macrumors 65816

    MattSepeta

    Joined:
    Jul 9, 2009
    Location:
    375th St. Y
    #1
    I am considering selling my 50D and upgrading to a 7D (mainly for the HD video capabilities, as well as higher FPS) and have a few questions for any 7D users...

    -Is there noticeably cleaner high ISO than the 50D?

    -I have heard/read alot about high mega-pixel count cameras having problems when paired with inadequate (non L in canons case) lenses. I plan on switching from zooms to mostly primes in the near future, so I am wondering if I will be able to get the most out of the camera with canons non-L primes, like the EF 28mm f/1.8 USM or a ultra wide zoom like the 10-22?

    Thanks!
     
  2. Grimace macrumors 68040

    Grimace

    Joined:
    Feb 17, 2003
    Location:
    with Hamburglar.
    #2
    The 28mm isn't that great of a lens, but the options at the wide end aren't that great if you don't want to plunk down lots of cash. If you have the focal range flexibility, the 50mm 1.8 and 1.4 are both better options.
     
  3. HBOC macrumors 68020

    Joined:
    Oct 14, 2008
    Location:
    SLC
    #3
    What about the Sigma 30mm? I have heard amazing things about that lens. I have also heard similar things about what you are saying about pairing the 7D with good glass. I have no desire for the 7D (1DS2, however..), so I haven't even looked at one.
     
  4. MattSepeta thread starter macrumors 65816

    MattSepeta

    Joined:
    Jul 9, 2009
    Location:
    375th St. Y
    #4
    Correct

    Thanks for the feedback. I noticed as well that the wide options pretty much suck unless you go for an L, and I dont feel that I should be forced to pay $2500 for a 14mm prime. I wonder why they have such limited options? If they can make a 10-22 ZOOM for around 700-800, I would imagine they could feasibly produce an ultra wide prime around the 10-12mm range for pretty affordable... Or is my thinking way off?
     
  5. Grimace macrumors 68040

    Grimace

    Joined:
    Feb 17, 2003
    Location:
    with Hamburglar.
    #5
    Primes usually are faster. The 10-22mm you mention is f/3.5-4.5 -- that is FAR different than a 14mm prime at f/2.8.
     
  6. toxic macrumors 68000

    Joined:
    Nov 9, 2008
    #6
    - high ISO is better with the 7D
    - high MP are not "harder" on lenses than lower, you just see imperfections more easily at 100%. if you only print at 8x10, then 5MP is just as hard on the lens as 500MP. final viewing size is what matters.

    wide lenses are inherently more compromised than longer ones - ever notice that all the sharpest lenses are telephotos? on top of that, ultra-wides are somewhat niche lenses, and primes are even more niche than that, so it might not be worth the R&D costs to Canon.

    the 28 isn't bad, but it's not exceptional, either. the Sigma 30 is a lot better. part of it I'm sure is the design - the 28 is a wide lens (i.e. compromised design) that happens to be standard on APS-C, while the Sigma is a standard lens (less compromised design).
     
  7. Ruahrc macrumors 65816

    Joined:
    Jun 9, 2009
    #7
    Between f3.5 and f2.8 is about a half a stop. The 10-22 at 14 is probably something like f/4 (one stop slower than f2.8). Different? yes, but not incredibly so.

    If you do a little rough sketching of the ray paths light has to take for wide angles and long lenses, you can see where the large differential in cost begins to come from. Light entering a long lens does not need to be bent all that much in order to form an image on the sensor. Wide angle lenses, however, need to bend the light to a far greater degree. This is why it is harder to design quality optics for the wide end.

    Ruahrc
     
  8. FX120 macrumors 65816

    FX120

    Joined:
    May 18, 2007
    #8
    Half a stop may not sound like much, but thanks to the logarithmic nature of focal ratios, it requires a 50% increase in light gathering capability, which when you start talking about faster apertures, becomes an increasingly greater amount of glass. A 300mm f/2.8 IS lens will cost you around $4400, while a 300mm f/4 IS will be around $1200. That's nearly a four-fold increase in cost for just one stop in performance.

    It is also worth mentioning that the EF-S 10-22mm images a smaller circle, and this also contributes to the significant decrease in cost compared to a faster zoom that would cover roughly the same range on a 35mm sensor (16-35 f/2.8L).
     
  9. HBOC macrumors 68020

    Joined:
    Oct 14, 2008
    Location:
    SLC
    #9
    When you compare a $2000 lens to a $500, you will then see why they are that much more (not they they should be that much, mind you).
     
  10. AlaskaMoose macrumors 65816

    Joined:
    Apr 26, 2008
    Location:
    Alaska
    #10
    A lot of lenses to choose from. Take a look:
    http://photography-on-the.net/forum/showthread.php?t=141406
     
  11. Ruahrc macrumors 65816

    Joined:
    Jun 9, 2009
    #11
    This is true but in terms of performance, half a stop is not as much as it may seem. One stop would cut in half your exposure time, and half a stop a bit less than that. So 1/20 sec at f/3.5 becomes ~1/30 at f/2.8. Is there a gain? Certainly, and it can make a bit of difference especially if you're on the border between handholdable and shaky shutter speeds. However, going from f 3.5 to f/2.8 is not a huge leap in speed, the "faster" prime is not going to really outdo the f/3.5 zoom. Sub that 2.8 prime with a 1.4 and then you've got some substantial speed difference.
     
  12. RainMeister macrumors member

    Joined:
    Sep 16, 2008
    #12
    I have the 28mm f/1.8, and it is not that bad of a lens. It's weak point is the softness in the corners with the lens wide open. On an APS-C camera, this is a non-issue since those outer corners are cropped by the smaller sensor.

    According to Castleman's test of the 28mm, other than the corner softness issue, it is comparable to L-series primes and zooms of a similar focal range.

    http://www.wlcastleman.com/equip/reviews/28mm/index.htm
     
  13. OreoCookie macrumors 68030

    Joined:
    Apr 14, 2001
    Location:
    Sendai, Japan
    #13
    First of all, forget about the red L, primes sold today usually have very high image quality, even the cheapest one, Canon's 50 mm f/1.8 (nicknamed yoghurt cup by some). Furthermore, I would prefer to have one or two more lenses instead of taking the most expensive one. Hence, I suggest you get a Sigma 30 mm f/1.4 or Canon 28 mm instead of a Canon 35 mm f/1.4 which costs more than 3 times as much.

    With regards to the 28 mm, I suggest you also take Sigma's 30 mm f/1.4 into consideration which is faster. I have one and it's my most-used lens at the moment.
     

Share This Page