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Messages - Stephen Melvin

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211
EOS Bodies / Re: 5D3 Auto Focus Question
« on: March 16, 2012, 12:56:26 AM »
what about the 16-35 f2.8L II doesnt it zoom backwards too? does that mean it in the same boat?

Well I said my hypothesis as to precisely why is a guess, but in any case, it is all about the location of the exit pupil.

That doesn't mean AF will be any less accurate with these lenses. The f/4 points are all cross-type, and they'll likely actually be looking close to the f/2.8 exit pupil. In any case, the 16-35 is going to have a lot of DOF most of the time.

I really wouldn't worry about this with any of the mentioned lenses. Unless I was one of the 24 people who owns the 1200 f/5.6L and saw that only 33 AF points work at all. ;)

212
EOS Bodies / Re: What does Sony know that we don't know?
« on: March 16, 2012, 12:48:31 AM »
It seems to me that Sony may be done with FF cameras of their own. But even if they're not, recall that they put the same 24mp sensor in their cameras as Nikon did in the D3x, but the Nikon has much higher image quality.

213
EOS Bodies / Re: 5D3 Auto Focus Question
« on: March 16, 2012, 12:45:38 AM »
While reading through the manual today I found it odd that the 24-70mm f/2.8 is classified as group B which gives it only a single dual cross-type AF point.

Can anyone explain why this and other f/2.8 lenses are put into group B and even group C (no dual cross-type)?

Thanks

It has to do with the exit pupil location of these lenses.

AF sensors are all about angles, not the quantity of light. F/5.6 sensitive AF sensors have a 10 degree offset (two sensors "looking" at opposite edges of the lens circle from the back) and f/2.8 sensitive AF sensors have a 20 degree offset. With lenses such as macro lenses, the exit pupil moves farther away as it focuses close, putting the edge of the circle outside the view of the AF sensors. The sensor is "blind" to the image, so the camera has to switch to an f/4 or f/5.6 AF sensor.

Same thing with the 24-70, which has an unconventional backward zoom, with 24mm extending the lens and 70mm making it shorter. At least, that's my hypothesis with this lens. ;)

I suspect the 24-70 Mk II will be able to utilize these double cross points.

The great news with this sensor is all of the f/4 sensitive cross points. I think this AF unit is going to be one of the best ever marketed by anybody. The D800's sensor is nothing but f/5.6 AF points, other than that single f/8 center point.

214
EOS Bodies / Re: Megapixel wars: Where do we go from here?
« on: March 15, 2012, 07:03:20 PM »
Oh, resolution has quite a way to go. The 35mm format will support between 100 and 200mp. Seriously.

I'm old enough to remember when new CD players were sold on the basis of "oversampling." "2x oversampling" and "4x oversampling" were common stickers on CD players. Why? Fidelity.

We're nowhere near the point where the sensors are oversampling. Just wait until we start seeing all of the aliasing from the D800E, and you'll see that there's plenty of room to go. We're still using low pass filters on our cameras because they need them. Even the D800.

We'll reach the limit when we no longer need the low pass filter because diffraction supplies all of the anti-aliasing we need. At f/1.4, that's over 100mp.

Speaking of the D800, the low light performance of that camera ought to put to rest the myth that more megapixels decrease low light capability. It's clearly a match for the Mk III in that department.

There is no real reason not to keep increasing the resolution of our cameras.

215
EOS Bodies / Re: 5D Mk III vs D800/E, is the 5D3 better at anything?
« on: March 15, 2012, 06:51:15 PM »

    • Autofocus in video.  I'm not a videographer, and I don't make movies.  But I'm a dad and I take pictures of my kids' sports.  I don't have the skill or desire to learn to try and manually focus 7 yr olds playing soccer.  Sure, I can buy a video camera, but then I have to lug extra equipment around, and still have inferior glass to what I already have for my DSLR

    You may find that the autofocus in video will leave a lot to desire, it's nowhere near the level of camcorders.

    Exactly. Accurate video AF of a 24 x 36mm sensor is much, much harder than with a tiny camcorder sensor, with its infinite depth of field. [/list]

    216
    Just read the manual of the 5D III, 1/250 as fastest time for auto iso is bloody stupid. Still usless for sport and action. Might be of use for weddings but that its. Why are they doing this to us?

    Not so useful for weddings, either. It automatically sets the ISO to 400 if a flash is attached and turned on, and maxes out at ISO 1600 if the flash head is set for bounce photography.

    I honestly don't know when the Auto-ISO function would actually be useful; the limitations Canon's put on it seem entirely arbitrary.

    217

    The 5D III has longer exposure times because the lighting is different. Look at the reflections of the lights in the bottles; you can see that one of the lights is much dimmer in the 5D shots than it is in the D800 shots. The shadows bear this out, too.

    You cannot make any judgment about the relative ISO sensitivity of the two cameras based on these photographs.
    Please help me understand this.
    So what you're saying is; 5D3 would outperform the D800 big time if the lighting conditions were the same, right? Well I mean, it has to be 'big time' to justify the 22MP sensor vs. the 36MP, right?

    That is not what I said. Reread what I wrote. I only said that you cannot make that kind of judgment based on the IR pictures.

    218
    The 5DIII  has longer exposure times at all ISO's compared to the Nikon , whenever I use high ISO it's hand held in poor lighting & the slowest shutter speed I can get away with so in the real world under poor lighting the D800 is going is going to deliver sharper pictures.
    The biggest plus point for the 5DIII seems to be smaller file sizes if you have an old computer & slightly faster frame rate.
    Big plus points for the D800  resolution & dynamic range & price.

    Both look to be great cameras but I'm amazed by the image quality of the D800 at base ISO which I use the most.

    The 5D III has longer exposure times because the lighting is different. Look at the reflections of the lights in the bottles; you can see that one of the lights is much dimmer in the 5D shots than it is in the D800 shots. The shadows bear this out, too.

    You cannot make any judgment about the relative ISO sensitivity of the two cameras based on these photographs.

    219

    Canon lens prices seem to be well more expensive that their Nnikon counterparts if you just look at the newer models like the 70-200,, f/2.8 MK II, and the 24-105mm L.  The 200-400mm L with its built-in TC is going to make the $7500 of the nikon 200-400mm Zoom look like peanuts.

    The 70-200 f/2.8L IS USM II is the same price or cheaper than the VR II Nikkor. (It's currently $100 cheaper.)

    The 24-105 f/4L IS USM is much cheaper than the 24-120 VR II Nikkor, and the Nikkor isn't as good. (The Canon is currently $200 cheaper at B&H.)

    The 24 f/1.4L II is $600 cheaper than the 24G Nikkor, and it's a better lens.


    So prices are getting pretty much the same.  However, Nikons reputation for service, and now their refusing to sell parts to small local dealers is user unfriendly to a extreme.

    No wonder Canon seems so confident about raising prices.  I'm going to give the 5D MK III a good trial, I think it will be the right one for me, but some of the features on the Nikon bodies look very nice.  If it weren't for the poor support and the unnecessary 36mp, I might be pretty convinced.

    Yeah, I'm with you. Also, in this area, Canons outnumber Nikons at least 10-to-1 in professional hands. I shoot a lot of events, and I almost never see Nikons. Last fashion show I shot, I saw one entry-level Nikon and one D300. Saw about a dozen 5D Mk II's plus various other Canons. I was a little surprised to seen any Nikons at all.

    My point being, we lend each other equipment from time to time. If I wanted a piece of Nikon gear, I'd have to rent or buy it.

    220
    Well this is pretty much all I needed to see. Apparently I'm about to become a Nikon-shooter.

    The only thing I will really miss is my 70-200 2.8 IS II, but I have heard that Nikon's version is equal in IQ.

    It is, but there are a couple of usability issues with the Nikkor vs the "L." First is the focus breathing issue. At minimum focusing distance, the Nikkor has the angle of view of a 135mm lens. The difference is very noticeable.

    The "L" behaves a bit more like a unit-focusing lens in this regard. Such dramatic focus breathing in a $2,500 lens is unacceptable to me.

    And the Nikkor's lens hood is very poorly designed. You cannot set your lens down on the hood, like you can with the Canon.

    I was briefly considering a move, too. Between the cost (nearly all of Nikon's professional lenses are more expensive than Canon's) and the issues with this lens and the 24G, in comparison to the equivalent "L's," quickly put that thinking to an end.

    Not to mention having to learn a completely different user interface, Nikon's poorer reputation for customer service, etc.

    221
    The Canon images are ~9mb. How can these be RAW files?

    The Nikon images are ~20mb.

    Certainly not a fair comparison.

    Unfortunately it appears canon has once again under rated their iso..as dxo mark has shown previously.  Canon is 1/2 to 2/3 stop lower than advertised. Errrr.


    I'm not sure how you've reached that conclusion. :/

    One thing I'll note is that you cannot judge the relative ISO sensitivity of these two cameras based on these photos. Look at the reflections of the lights in the bottles. If you look closely, you'll see that the upper-right light in the 5D III photos is much dimmer than the other lights. The shadows are different for the 5D III photos as well. There's less light in the 5D III photos, so they adjusted the exposure to compensate.

    222
    Lenses / Re: Purchase thoughts: Canon 5d3 or 24-70L II?
    « on: March 13, 2012, 11:56:36 PM »
    I think you should get the camera this year and the lens next year. Canon's history with the 70-200 suggests the price will come down a bit in a year or so, and they do have the rebates from time to time as well.

    The camera likely won't drop in price for a couple of years. You miss having professional AF, so why not get it now?

    223
    EOS Bodies / Re: 5D Mk III vs D800/E, is the 5D3 better at anything?
    « on: March 13, 2012, 11:45:24 PM »
    It recently occured to me after Nikon announced that with a grip the D800 shoots 6 FPS that I can't find a single advantage to the 5D3 over the D800. Here's what I know so far:

    5D3 vs D800/E by catagory:

    Dynamic Range: Inferior
    Color Fidelity: Inferior

    Color Fidelity? All modern dSLR's have excellent color fidelity; way better than film ever was. It's really irrelevant unless you're in the art reproduction market.

    Noise: Equal
    FPS: Equal (with a grip)

    The "with a grip" nonsense is idiotic, IMO. Nikon's stuck in the 1970's with this notion.

    Video: Inferior

    We don't know that. Early tests seem to indicate Nikon's video is pretty mediocre. Early tests also show the 5D Mk III outputting 1080i video from the HDMI port, so that D800 advantage may be nothing.


    Autofocus: Equal (both are pro level)/Inferior (no f/8.0)/Superior (better with fast lenses due to special f/2.8 sensors)
    White Balance: Inferior
    Auto Exposure: Inferior

    We don't know that, yet.

    In Camera Lens Correction: Inferior

    You shoot a lot of jpegs? I didn't think so.

    Pop up Flash: Inferior
    Price: Inferior
    Resolution: Inferior
    AA filter: Inferior

    Oh, you got that one backward. The AA filter is necessary, unless you like your images to be full of stair stepping, false color and moiré. Removing the AA filter is a very quick way to ruin photographs to the point of uselessness.

    I realize that the 5D3 has a better menu system, so that's one thing it can possibly do better.

    Don't forget its wider ISO range, access to the largest system of professional lenses in the world, and a service department that's second to none. Did you read about Nikon putting the smackdown on independent camera repair shops? This is not a very consumer-friendly company we're talking about here.

    Don't forget the total cost of ownership. I recently did the math to replace my "L's" with equivalent Nikkors. It would have cost me about $1,200 more than it cost to buy my Canons; and I used Nikon's "refurbished lenses" site to get their prices.

    Also please don't smite me. I'm not trying to bash the 5D3, as I'm actually a Canon fan and will be getting the 5D3, but can anyone think of one major feature that the 5D3 does better than the D800? If so feel free to post, I'm just trying to get informed here.

    Thanks. :)

    My sole complaint about the 5D Mk III is Canon's inability to get a handle on low ISO read noise and improve the dynamic range. I'm pleased with the new high ISO capability, and I love most of the other upgrades. It's what the Mk II should have been.

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