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  • Jarek Zabczynski
    replied
    Originally posted by dop16mm View Post
    Our frame of reference if you want to talk crop factor should be the 1/3" cameras we've worked with for years. The widest standard zooms for these cameras is 4-4.5mm or 16 - 18mm in 4/3 format. You can't adapt much wider than that without introducing barrel and fish-eye distortion.

    If you've been working with consumer cameras like the canon hv20 type the wide end is 6mm or 24mm in 4/3, again you can't go much wider without distortion.
    Here's my question.

    My reference for wide angle has been the DVX and HVX. When I shoot with my 35mm adapters I tend to just take them off and shoot "stock" for my wide angles. What is the mm lens equivalent on the HVX? Or what mm lens would I need to get for the AF-100 to match the wide angle FOV that I get with my HVX?

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  • SteB
    replied
    Originally posted by Barry_Green View Post
    Are you sure about that? I thought the dpreview tests showed that the barrel distortion and pincushion distortion correction was only being done by the Panasonics. They test lenses on both models and you can click on the tests to see how they compare on different bodies. I may be wrong, but I thought they showed noticeable barrel distortion on the 14-140 at 14mm on the Olympus, but on the Panasonic it was rectilinear?
    I'm pretty certain that Olympus m4/3 correct for everything that Panasonic do, except for CA. As always the difficulty has been finding a quick source to confirm this. However, I did find this interesting thread from Dpreview last year in which this was discussed by several Dpreview staff members.
    http://forums.dpreview.com/forums/re...ssage=32614954

    There is an interesting comment by Andy Westlake of Dpreview, where he first says the distortion correction is applied equally by Panasonic and Olympus, but then in another post states.

    Yes, your interpretation is correct; Olympus seems not to be correcting distortion fully, for no obvious reason. Maybe they're trying to fool us into thinking they're not doing distortion correction at all...
    So yes it does appear that there may be a slight difference in the degree of correction. There is some other info in this Dpreview article about m4/3 lens software correction.
    http://www.dpreview.com/articles/distortion/

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  • Barry_Green
    replied
    Originally posted by SteB View Post
    Just a quick note on this. From what I understand Olympus m4/3 cameras perform all the same corrections as Panasonic m4/3 cameras, with the exception of CA correction that only Panasonic bodies do.
    Are you sure about that? I thought the dpreview tests showed that the barrel distortion and pincushion distortion correction was only being done by the Panasonics. They test lenses on both models and you can click on the tests to see how they compare on different bodies. I may be wrong, but I thought they showed noticeable barrel distortion on the 14-140 at 14mm on the Olympus, but on the Panasonic it was rectilinear?

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  • SteB
    replied
    Originally posted by Barry_Green View Post
    It does. I used my 14-140 and 7-14 on the AF100, and it worked all the same magic that my GH1 does.

    Agreed, the 7-14 on the Olympus was at a bit of a handicap; it would have performed even better had they tested them on a Panasonic body.
    Just a quick note on this. From what I understand Olympus m4/3 cameras perform all the same corrections as Panasonic m4/3 cameras, with the exception of CA correction that only Panasonic bodies do.

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  • Rick Burnett
    replied
    Agreed. I think it is worth reiterating again that the m4/3 size is still not hugely prevalent, and hopefully as it becomes more prevalent, we'll get more options. That's the biggest problem. We've had Nikon and Canon glass to compare and contrast on cost and capability.

    What would be interesting to compare them both at 11mm.

    One thing that can be said is this, if you NEED 7mm, at least there is an option. I think that is important as well. Sure, you have to light it more, but at least the lens exists. I'd rather at least know that option was out there then have nothing at all. Which would be WAY worse.

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  • dcloud
    replied
    tokina 11-16 does really well on all accounts
    sharpness
    distortion
    CA

    I agree with grimepoch regarding this lens.

    you should run it some tests barry. i think its a great wide zoom.
    Last edited by dcloud; 11-16-2010, 12:35 PM.

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  • Barry_Green
    replied
    Originally posted by grimepoch View Post
    I just don't notice a problem with either of those issues with my Tokina 11-16mm. I've seen others post CA from the Tokina, but when I try the same test, I've not gotten the same results. Likewise, I've analyzed screen grabs in photoshop and I've not seen appreciable barrel distortion either.

    Take into consideration that the m4/3 sensor is slightly smaller than the APS-C that I used and the lens just gets better since we lose more of the outside. Doesn't make them worth the investment to me. I'd rather get a lens that looks correct BEFORE the sensor, not after.
    Well, keep in mind that the 7-14's are massively wider angle than the 11mm of the Tokina. Barrel distortion gets worse the wider you go, and 7mm is as much wider than 11mm, as a 50mm lens is versus an 80mm. Huge difference.

    Second, I totally agree -- I'd rather have perfectly-performing optics, than digital correction. Definitely. But with that said, perfect glass costs dough, and sometimes the electronic corrections are good enough and they bring the price way down... the Arri Ultra Prime 8mm is probably the finest 8mm glass on the planet, and performs largely rectilinearly and I would presume it has excellent CA performance and edge sharpness (although that's a guess, I don't know). However, the question becomes -- is that one f-stop, and the optical performance, worth a price difference of $29,000? For some, yes. For most, no.

    In theory I'm totally all in favor of perfect optics instead of digital correction. Always. But when the wallet hits the road, the digital route is sometimes "good enough" considering the profound price difference.
    Last edited by Barry_Green; 11-16-2010, 12:19 PM.

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  • Rick Burnett
    replied
    Originally posted by cowpunk52 View Post
    True, but that's not always easy or cost-effective. I find the in-camera correction of the Lumix 7-14mm lens on Panny bodies to be incredibly good, virtually indistinguishable and for the most part outperforming the best optical-only ultra-wides on Panasonic bodies. There's no way on earth most AF100 users will ever be able to afford a lens that performs optically the way the 7-14 does does with digital correction. For the performance at it's price point, it's one of the best wide-angle options available - especially for video work, in any format. You'd have to spend literally tens of thousands more dollars to get a completely optical equivalent performance.
    Well, that is true. And a good point. For me, it's a special case as I said I do a lot of VFX work and believe me when I tell you that HD-SDI port can't get here fast enough for me. But, not everyone has these limitations. I use the Tokina all the time with VFX work and have not had a problem with it yet related to barrel distortion or CA. For this reason, comparing it to the 7-14 with regards to those issues is a non-point for me, so the extra cost doesn't make any sense for fixing those issues compared to my Tokina lens. I'd also MUCH rather have my Tokina at F2.8 at 11mm which will be more versatile for me. That's why I said renting the 7-14 is the best option for me if I am doing something that could use that, but that I'd not use the lens that often, and definitely not indoors.

    Don't get me wrong, it's a neat lens focal length wise, and the outdoor footage I have seen is really neat, but for the cost, for me, not worth it. Plus, just because ONE lens exists at this price point AND these characteristics are not indicative of all that is possible or probably. As said, m4/3 doesn't have a huge history or foothold yet.

    I think the problem is not the possibility, but the market size. If lens manufacturers don't see a big enough return on investment on these smaller focal lengths for m4/3, then they won't build anything for them. I mean, how often would you use 7mm with that EXTREME perspective distortion? Even with my 11mm, I tend to use it VERY sparingly.

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  • cowpunk52
    replied
    Originally posted by grimepoch View Post
    This will ALWAYS be better than a digital solution.
    True, but that's not always easy or cost-effective. I find the in-camera correction of the Lumix 7-14mm lens on Panny bodies to be incredibly good, virtually indistinguishable and for the most part outperforming the best optical-only ultra-wides on Panasonic bodies. There's no way on earth most AF100 users will ever be able to afford a lens that performs optically the way the 7-14 does does with digital correction. For the performance at it's price point, it's one of the best wide-angle options available - especially for video work, in any format. You'd have to spend literally tens of thousands more dollars to get a completely optical equivalent performance.

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  • Rick Burnett
    replied
    Originally posted by tflak View Post
    And I'd rather shoot an actress who looks great BEFORE makeup, not after.

    Seriously, what I care about is how something looks on the final delivery vehicle it's intended for. If it looks good there, I don't really care how much processing it went through to get there. Especially if it's seamless and didn't cause me any extra work.
    Ahh, but you illustrate my point for me. Do you want to fix the actress BEFORE the sensor, or after the sensor? Clearly you'd rather add the makeup before the sensor then having to photoshop the frames after the fact.

    I'm just reluctant to use any digital fixes on a lens. You are applying distortions to an image which is changing the pixel relationships. For most people this might be fine, but for all the VFX work I do, I need to reduce the number of issues, not add more. Wide angle shots are REALLY hard to work already if the camera moves at all due to perspective distortion, which all ultra wide lenses will have and you cannot remove because that is the nature of the FoV. Same thing with CA fixes. I'd rather get a lens that will be right to begin with, then have the software which already has to interpolate between bayer sites then have to apply fixes to the color. No thanks. Not that I wouldn't use the lens, or try it, but I'd always opt to spend more on a lens that gets it right optically first. This will ALWAYS be better than a digital solution.

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  • tflak
    replied
    Originally posted by grimepoch View Post
    I'd rather get a lens that looks correct BEFORE the sensor, not after.
    And I'd rather shoot an actress who looks great BEFORE makeup, not after.

    Seriously, what I care about is how something looks on the final delivery vehicle it's intended for. If it looks good there, I don't really care how much processing it went through to get there. Especially if it's seamless and didn't cause me any extra work.

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  • Rick Burnett
    replied
    Originally posted by Multi-Media View Post
    That's all well and good, but the Tokina won't work with the camera to perform barrel distortion correction... or chromatic abberation correction. The Panny lenses work WITH the camera... That's what makes them worth the investment.
    I just don't notice a problem with either of those issues with my Tokina 11-16mm. I've seen others post CA from the Tokina, but when I try the same test, I've not gotten the same results. Likewise, I've analyzed screen grabs in photoshop and I've not seen appreciable barrel distortion either.

    Take into consideration that the m4/3 sensor is slightly smaller than the APS-C that I used and the lens just gets better since we lose more of the outside. Doesn't make them worth the investment to me. I'd rather get a lens that looks correct BEFORE the sensor, not after.

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  • Barry_Green
    replied
    Originally posted by aguia View Post
    It seemed to me that the Panasonic was still performing better than the Olympus in this test, but I have been curious whether an AF100 will do the same kind of in-body software correction for aberrations that the GH1/2 will. It is something else to consider, I think that Panasonic is fully into using in-camera processing to sweeten their lens designs. In fact I'm sort of surprised the Panasonic 7-14mm did as well as it did in this test (on an Olympus body).
    It does. I used my 14-140 and 7-14 on the AF100, and it worked all the same magic that my GH1 does.

    Agreed, the 7-14 on the Olympus was at a bit of a handicap; it would have performed even better had they tested them on a Panasonic body.

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  • aguia
    replied
    Originally posted by Barry_Green View Post
    Wow, they sure didn't seem to like either lens a whole lot!

    Well, a couple of things to consider, when comparing those two:
    1) the Olympus is nearly twice the price of the Panasonic
    2) they tested on an Olympus body, and that doesn't let the Panasonic lens do its wizardry. The Panasonic lens and body, together, have electronic communication and the ability to resolve issues such as chromatic aberration and barrel distortion. Those features don't come into play when you mate a Panasonic lens onto an Olympus body.
    3) They caution about f/22 on these lenses, but I'd say f/22 on any DSLR lens is problematic, due to diffraction. I recommend staying no deeper than f16 anyway.

    Because of those factors, I went ahead and got the 7-14, and I kind of love it. Some of my favorite shots I got were at the 7mm focal length. But it does become distracting to do a pan that wide, as the perspective changes from the corners to the center of the frame, so I don't think it's the first lens anyone's going to reach for when doing general-purpose cinematography. But for a fairly-rectilinear ultrawide, I think it's pretty good and I'm happy with it.
    It seemed to me that the Panasonic was still performing better than the Olympus in this test, but I have been curious whether an AF100 will do the same kind of in-body software correction for aberrations that the GH1/2 will. It is something else to consider, I think that Panasonic is fully into using in-camera processing to sweeten their lens designs. In fact I'm sort of surprised the Panasonic 7-14mm did as well as it did in this test (on an Olympus body).

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  • Multi-Media
    replied
    Originally posted by J Davis View Post
    I realize that but things get easier when your image circle is smaller. Plus we're talking primes not a zoom.
    I still think $900 for a m43 image circle f2.8 prime at 7-8mm is realistic.
    especially when tokina make a fixed aperture zoom at 11-16 f2.8 for $600 and
    sigma make a reclitlnear 8-16mm zoom f4.5 for $700 and both these are
    zooms, more complex with more elements and larger image circles.
    That's all well and good, but the Tokina won't work with the camera to perform barrel distortion correction... or chromatic abberation correction. The Panny lenses work WITH the camera... That's what makes them worth the investment.

    Leave a comment:

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