LX7 or 14-42 X for GX1?

Discussion in 'Open Gear Talk' started by Biro, Mar 20, 2013.

  1. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    Like others, I have been tempted to spring for the sub-$300 deal on the Panasonic LX7 being featured until the end of the month by Amazon.com. In addition to having a pocketable, fixed-lens camera, I like the idea of being able to use the Panasonic LVF2 on it if I want (I already own this EVF for my GX1). But the very fact that I own the GX1 also causes me to pause and wonder if it might be better to opt for the Panasonic 14-42 X power-zoom pancake lens instead of the LX7.

    The GX1 isn't much larger than the LX7 and when I need more flexibility than the 14mm or 20mm pcankes can give me, the power-zoom lens would keep the size down. Yes, I know the aperture is slower: f/3.5-5.6 versus f/1.4-2.3 for the LX7's fixed lens. But the four-thirds sensor in the GX1 is quite a bit larger than the 1/1.7" sensor in the LX7, which would mean the ability to gather light and achieve a narrow depth of field at the wide end would be enhanced.

    And this is where I'm asking some of our best and brightest to do some calculations. When one crunches the numbers, am I better off with the GX1's larger sensor and slower lens... or the LX7's smaller sensor and faster lens? Beyond this, if anyone has any thoughts on which way to go, by all means feel free to chime in.
     
  2. Luke

    Luke Super Moderator

    Nov 11, 2011
    Milwaukee, WI USA
    Luke
    I'm probably the wrong guy to ask (not the best or the brightest). I see you already have the Lumix 14-45 and the Oly 14-42 IIR. I would say you are covered well enough in the slow zoom category....why add another? If I were you, I'd buy the LX7.
     
  3. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    You raise a very good point. I am in the process of thinking aloud on this.
     
  4. Armanius

    Armanius Bring Jack back!

    Jan 11, 2011
    Houston, Texas
    Jack
    If I recall correctly, the 14-42X had some issues at the long end of the zoom, and at certain shutter speeds.

    Just as a counterpoint to Luke, you already have a EPM2 and a Pentax Q. So it seems that you have the "small" cameras covered pretty well!

    ps: Ironically, that's never stopped me from getting another one! :)
     
  5. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    bart
    for narrow DOF, the things that matter are physical aperture size (larger = shallower), equivalent focal length (longer = shallower), subject distance (closer = shallower, but irrelevant in comparing cameras / lenses), and magnification / circle of confusion (larger magnification / smaller COF = shallower). At the wide end, the LX7's physical aperture size is 5.1/1.4= 3.64mm, and the PZ lens is 14/3.5= 4. Taking into account the fact that the PZ has a slightly longer EFL but also considerably less magnification / larger COF, I'd say the shallow DOF abilities are pretty much identical, or even be better for the LX7. You might want to visit one of those DOF comparison sites to be totally sure.

    At full tele, the LX7's physical aperture is 19.2/3.3= 5.8mm, and the PZ is 42/5.6= 8.0. Given the slightly longer EFL for the LX7 (90mm) and its larger magnification, it should make up a little of the difference but I'd still expect the PZ to have somewhat shallower DOF, but not a whole lot. Again, the DOF comparison sites could've given you the answer with more certainty and probably quicker than it took you to read this (or for me to type this), but typing my guesstimates is a nice diversion from thesis writing so there you have it :smile:

    Light gathering ability... IIRC, the LX7 has a roughly 4.8 crop factor versus a 2 crop factor for m43, so that's a diagonal of 2.4 times as large, so about 2.5 stops more light gathering ability for the sensor alone. At wide angle, f/1.4 is about 2.5 stops faster than 3.5, and at tele f/3.3 is about 1.5 stops faster than 5.6. So at wide angle, sensor+lens light gathering ability should be roughly equal whereas at full tele, the m43/PZ combo should have roughly 1 stop better light gathering ability, assuming equal sensor efficiency.
     
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  6. Luckypenguin

    Luckypenguin SC Hall of Famer

    Dec 24, 2010
    Brisbane, Australia
    Nic
    The LX7 will give you a 24mm equivalent at the wide end vs 28mm on the 14-42X. There were some initial problems with the 14-42X at certain shutter speeds due to the OIS element, but I haven't seen any further reports about this recently so maybe the issue has been quietly resolved . My personal preference would go the larger sensor and slower lens, but the different packaging and controls of the LX7 may hold more appeal to you. The question I would ultimately ask myself is how much interest do I have in the LX7 as a camera as opposed to merely being a great deal at $299.
     
  7. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    I don't know if the issues were with the 14-42 X or the 45-175 X. And you're right about my already having some small cameras. But the LX7, with lens retracted, does pack down a bit more than the others. And I would only consider it at the current price or lower.
     
  8. Ray Sachs

    Ray Sachs SC Legend

    Sep 21, 2010
    Not too far from Philly
    you should be able to figure it out...
    The LX7's lens opens to f2.3 at the long end - you seem to be using 3.3 in your assumptions/calculations.

    -Ray
     
  9. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    bart
    you're right! 3.3 was the LX5's maximum aperture at full tele. That would make the LX7's physical aperture at full tele 8.3mm, meaning the LX7 should have at least as shallow, and quite possibly even shallower, DOF all along its range. Light gathering ability: f/2.3 is about 2.5 stops faster than f/5.6, so the LX7's lens should be fast enough all along its range to cancel out the m43 sensor's size advantage. Cool!
     
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  10. Luckypenguin

    Luckypenguin SC Hall of Famer

    Dec 24, 2010
    Brisbane, Australia
    Nic
    It was definitely an issue with the 14-42.
     
  11. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    Okay then! That's the information I was looking for! Thanks so much.
     
  12. bartjeej

    bartjeej SC Hall of Famer

    Nov 12, 2010
    bart
    Hmm wait a second! The online DOF calculators seem to think I'm not as clever as I hoped I'd be, they say the DOF is a good bit shallower for the m43/PZ combo! Haven't quite figured out what's wrong with my calculations yet though:confused:
     
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  13. entropic remnants

    entropic remnants SC All-Pro

    Mar 3, 2013
    John Griggs
    I got the LX7 strictly for portability while still maintaining good control and the advantages of a good f/1.4 lens for that small sensor. I shoot wide far more than I shoot tele so that's a good thing for me.

    I thought about the PZ 14-42 for my E-PL5 but it's still very thick with that on it. Pocketability is something the LX7 pushes the edge of for sure -- but for me the m43 alternatives were just too big. I haven't actually seen a GX1 in person so that might be a great alternative. The LX7 with the lens cap on is just under 2" thick for reference.

    If maximum quality was the issue though, I would think the GX1 wins -- though I don't mind the quality from the LX7 for most shooting with a walkabout camera.
     
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  14. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    We're talking about a walkabout camera for me in this case as well. Thanks for the LX7 thickness measurement.

    EDIT: And here's our size comparison...

    http://camerasize.com/compact/#183.335,350,da,t
     
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  15. Ray Sachs

    Ray Sachs SC Legend

    Sep 21, 2010
    Not too far from Philly
    you should be able to figure it out...
    Neither of these options are anything to write home about if narrow DOF is your priority. With the LX7 you can get narrow DOF in macro mode doing extreme close ups with blurred background. Other than that, forget about it. The GX1 with the kit may not even give you that. I wouldn't worry about small differences in the narrow DOF department, because there just innt much. As Billy Preston sang back in the day, "nothin' from nothin' leaves nothin".

    -Ray
     
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  16. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    No, it's not critical... that wouldn't be the purpose of this camera. I'm just trying to see if one set up has a noticeable advantage over the other. If not, then having an LX7 will be a lot of fun.
     
  17. entropic remnants

    entropic remnants SC All-Pro

    Mar 3, 2013
    John Griggs
    Narrow DOF is as Ray says a difficult thing. But it's a wide enough aperture to give you enough blur wide open to separate your subject from the background if the background cooperates by being far enough away like here, lol. This is 90mm equivalent wide open at f/2.3.

    8556794317_aab5ac3b38_z.
    Emergency Response: Chief Anthony Goode by Entropic Remnants, on Flickr
     
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  18. john m flores

    john m flores SC All-Pro

    Aug 13, 2012
    Whatever you do, don't blame me. :wink:
     
  19. Biro

    Biro SC All-Pro

    Aug 7, 2011
    Jersey Shore
    Steve
    John... some people have spiritual advisors. You are my photographic zen master.
     
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  20. john m flores

    john m flores SC All-Pro

    Aug 13, 2012
    I think you meant, "Guy on the Internet that helps you rationalize all of those cameras." LOL.

    Seriously, the lens for the GX1 makes more sense unless you'd really like 24mm and/or macro. Then the LX7 gets the nod.

    Me? I got the LX7 for the 1080P60 and 720P120 video. That's my story and I'm sticking to it.
     
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