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Messages - rs

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EOS Bodies - For Stills / Re: More body upgrade from 40d questions???
« on: August 07, 2013, 06:02:00 AM »
You have a good body.  You want more reach... you don't need another body, you need another lens.  THe 50-500 Sigma will also AF, wheras your 70-200 and 70-300 may struggle once teleconverted.
I agree - the 40D is a great camera (I still use mine), and quality reach seems to be your main shortcoming. But I'd recommend staying away from the Sigma 50-500. A non stabilised small aperture telephoto lens can be a bit of a handful. I guess you'll be using it for much more than just birds in flight? (BIF shots can only easily be pulled off with the new mode 3 IS)

I'd recommend pj1974's advice, sell up your two tele zooms, and get a 70-300L. As far as I know, the Sigma 50-500 is meant to be a short 500, so the difference in framing isn't as much as you'd expect between the two.

Even though the 70-300L isn't designed to work with TC's (it will at a pinch), the superior optics of the 70-300L should give you better quality if you crop to get the same narrow angle of view:

This comparison isn't a 100% match of what you could do as the 70-300 is on an 18MP crop (not a crop of a 10MP crop as I'm recommending), and the 50-500 is on FF (not an uncropped crop ???), but the crop factor is roughly equal to what you could do in post. The 300 is cropped to a field of view of 480mm here, and it looks sharper than the 500 (in reality, just a 450-470mm) natively.

EOS Bodies / Re: Could "dual pixel" help DR (HDR)?
« on: August 05, 2013, 05:08:17 AM »
People concerned about "weird bokeh" need not be. Just think about a (non-Xtrans) bayer array, there's only red and blue in alternate lines. Does the bokeh turn out with weird colours? No, it's all interpolated and corrected in software.
The main difference is everything that has gone before (be it monochrome sensors, bayer, x-trans, foveon) has had each and every photosite capturing the same angle of view. This dual pixel AF sensor is different. Each photosite (sub pixel) is only able to see half of the phase.

Imagine for a moment that you could capture an image independently from the left and the right hand phase of this dual pixel sensor (which Canon will obviously not let you do natively). If you've got everything in focus, the two halves will look identical, but if the something is out of focus, it will appear in a different place on the frame in the two images (think of a split image focusing screen).

Instead of a full sized square photodiode behind the microlens, there are two photodiodes - according to the canon marketing material, they are rectangular in shape, together forming a square of the size/shape of a normal photodiode, with a vertical division. This will allow one side to see one phase, and the other side, the other phase. Theoretically if you have a perfect point source of light (bright, about the size of one pixel should it be in focus) out of focus, together the two phases will see a perfect circle of blur. But on its own, the one side would theoretically see just a semi-circle of blur, with a vertical cut off. The other side will see the other half.

This is not going on over the width of just one sub pixel, but could in extreme cases of blur (think 85L wide open at close focusing distances) cover half the frame. Unlike with a bayer sensor and a simple AA filter to blur out neighbouring pixels, there is no way you can re-assemble this data meaningfully if each half is exposed differently, and one half is blown out.

The only way I can picture it working is to do something along the lines of staggering it - one dual pixel having left underexposed, right overexposed, and then the next dual pixel being the opposite way around - left overexposed, right underexposed. That way, some post processing could look at them in pairs of left phase, and check first of all to see if the overexposed channel has blown out (if so, use the neighbours underexposed left phase value). And secondly, do the same for the underexposed channel if it gets down to the noise floor. Without doing that, bokeh would look odd.

EOS Bodies / Re: Could "dual pixel" help DR (HDR)?
« on: August 04, 2013, 01:37:12 PM »
I'd imagine there would be some interesting effects in the bokeh, should this be done - presuming a hack along the lines of the 7D/5D3 with alternating lines, you'd get the left half of every pixel exposing for shadows and the right half of every pixel exposing for highlights. As each half sees a different phase, out of focus areas could take on a strange look - for example, an OOF bright light source could end up with one half of the bokeh ball being close to full white, and the other being mid grey (the shadow channel would be blown out).

If they could alternate between the left and right halves for the two exposures, it could alleviate this potential problem.

Technical Support / Re: Can't transfer RAW files, only JPEGs
« on: August 03, 2013, 02:18:02 PM »
I noticed this when using Windows XP connected directly up to a 40D. I believe its caused by Windows not having the correct codec installed to natively read the CR2 files, and the camera and computer work that out together - and as a result the camera gives you a helping hand and converts the CR2's to jpegs before sending them down the USB cable.

Whatever the actual cause, using a card reader to copy them off again is a simple work around - what is stored on the card is still CR2 + JPG. Failing that, experiment with installing CR2 codecs, and then try copying again direct off the camera?

Software & Accessories / Re: What size RAW should I shoot at?
« on: August 02, 2013, 05:58:51 PM »
That being said, if S-RAW has a resolution of 2736x1824, which is quite a bit larger than an HD resolution of 1920x1080, does it really matter if I shoot at 5M?
'HD' resolution is just a stepping stone for computer displays. Apple already have the 15" Retina MacBook Pro out with a 2880x1800 16:10 display. At 100%, S RAW won't fill that screen. It's only a matter of time before there's a 27" Retina display with an expected 5120x2880, and as this display technology becomes more mainstream, Windows will get native support for it too.

While you can rightly argue only a select few have this technology now, don't you want the moments you're capturing to stand the test of time?

Lenses / Re: Buy 50mm f1.2L now or wait for the II?
« on: July 31, 2013, 04:47:40 AM »
The 50L suffers from focus shift, which is where stopping down the lens changes where it focuses. AF is performed wide open, so it should nail the focus at f1.2 - but stop it down, and it will be slightly off. If you stop down as far as say f5.6 or f8, the increased DoF should be enough to keep your subject in focus. But apertures between wide open and large DoF settings will be affected by varying amounts. Someone with plenty of hands on experience should be able to provide more accurate info than me, but I believe the 50L suffers from focus shift the most at about f2

Like apertures, common focal lengths tend to follow multiples of the square root of two.

So, 24 (close to 25), 35, 50, 70 (OK, that's not a good example as 85 is used instead), 100, 135 (close to 141), 200, 300 (close to 283), 400 etc.

TC's follow this pattern too.

I guess it all centres around the 'normal' 50mm lens, even though 43mm is a better fit for a 35mm frame.

As for the actual focal lengths and apertures of lenses, remember the specs quoted are usually a near fit for the actual real life specs of the lens (as is often revealed in the patents), so they tend to get rounded to the nearest fit.

Canon General / Re: People that don't shoot in manual...
« on: July 30, 2013, 03:14:38 PM »
Talking about fetish, I find annoying  >:(  people who don't use lens hoods.
I find it amusing when people shoot with the lens hood reversed on the lens. Is it just me, or are they mostly Nikon shooters?  ::)

Lenses / Re: Buy 50mm f1.2L now or wait for the II?
« on: July 30, 2013, 03:12:14 PM »
I think I know now what primes I will be getting in the next few months / years.

35L + Sig 50 1.4 + 85L + 70200 IS II

I skipped the 50L after countless bad reviews I found on the net, the other L doesn't seems to have many negative reviews though so my money is hopefully worth to spend on
I have the 70-200 II and the Sigma 50/1.4. Both great lenses, but be prepared for a little bit of hassle when it comes to getting a good copy of the Sigma.

Many people have had to return theirs two or three times to get a good copy. I was lucky, and it took just one swap out (the first one had major AF issues). Sharpness of this lens is very good - better in my opinion than the Canon 50's, and no focus shift when stopped down. Out of all my lenses (including three L lenses), the Sigma's bokeh quality is in a whole different league. I've used the Canon 50/1.4 quite a bit, and that Canon doesn't get even remotely close to the Sigma.

Canon General / Re: People that don't shoot in manual...
« on: July 30, 2013, 02:59:41 PM »

I realize there are car afficionados out there who love their stick shift, but why not take advantage of the dual clutch auto and all the extra speed it gives you :).

Oh had the analogy going VERY well, until the end there with the car attempt....<P>

For a sports car, especially a high end sports car, you want a manual transmission...if not for resale value, but for performance.

You're generally gonna get the better times and stats with manual over automatic, if you know how to drive the manual...

I've never owned a car with auto transmission, and only one car have I ever owned had more than 2 seats (that one was an '86 911 Turbo, but those rear seats aren't really useable for anything but 2x bags of groceries).....

LOL...anyway, good thoughts on the camera, but ugh...a sports car with auto transmission? A waste of good steel....


OMGzzzz!!1!!one!1!!!!!! I'd never even drive an automatic! I am British though, and those things are quite rare here. Why would you let the car decide what gear you need to be in?

I'm possibly the only person that will survive when the robots take over, it appears.
I prefer manuals, but I would settle for an F-Type

Canon General / Re: People that don't shoot in manual...
« on: July 30, 2013, 11:18:15 AM »
For most of my commercial work, speed is of the essence. As a result I typically need to know the exposure is sorted out for me - composition and timing is far more important than having the satisfaction of knowing I tweaked every last little setting on the camera to technically pull it off.

When I need to control DoF (events such as weddings), I shoot Av, and tweak the ISO to suit to keep the shutter speed the right ball park as is needed. When I need to control shutter speed (such as sports), Tv. Same thing, keep an eye on aperture and tweak the ISO when needed. I also freely use exposure compensation to suit. Only when shooting with a flash do I use M.

To improve my speed and control, from time to time I would really like even more automation - the ability to use M, select the aperture and shutter speed for the task in hand, and have auto ISO with exposure compensation at the same time. That way when shooting action shots (or anything really), I can finely control DoF and motion blur, and know the exposure will be worked out for me, with my desired compensation dialled in. To make that work fast it would require three control dials, so the current Canon bodies couldn't handle it even with a firmware update...

If you want to use the same applications as you do on a PC, your only option is one that runs Windows — like the Microsoft Surface Pro. iPads, Android tablets like the Nexus 7 etc etc won't run Windows software.

Graphics, performance and RAM won't be of a concern on any modern Windows tablet unless you want to do full-blown Lightroom editing on them.
If you want to run native Windows 8 apps on a tablet, make sure you don't get a Windows RT tablet. Also Canon don't make a WiFi remote application for any version of Windows - you'll need iOS or Android for that.

Lenses / Re: Buy 50mm f1.2L now or wait for the II?
« on: July 28, 2013, 03:05:35 PM »
OOT a bit, as I will be mostly doing portraiture thingy (outdoor), other than the 50 f1.2, which one should I choose between the 135f2 and 85 f1.2?
Focal length for portrait very much depends on how tight you want to crop - head and shoulders, upper body, or whole body. So your best bet is to experiment and find out what you're most happy with.

Your crop camera, 50 and 85 will give you a good idea of what an 85L and 135L's focal lengths are like on FF. (your 50 acts like an 80, and your 85 acts like a 136) - so try them out, and then bear in mind how long you'll be using the lens on your crop camera before buying a 5D3.

The 85 is a middle ground between the 50 and 135, so its probably best not to get all three - you'll probably not end up carrying all three around, and even if you did, you'll no doubt not use all three in one session.

If you want to go with a 24 and 50, the 135 could be best. If you're happy with just two primes, 35 and 85 could be the way to go.

EOS Bodies / Re: 'Revolutionary' Dual Pixel AF Explained
« on: July 26, 2013, 05:24:02 PM »
I'm concerned about the 100mm f/2.8 Macro (non-IS), which I own. This is a currently sold lens, and the document said that dual pixel would support all current lenses, but the macro is on the list of lenses that are not fully supported. This seems like a contradiction. This is the only high quality current lens that I noticed on the list that is not fully supported.
If the lens on that list has USM, it says USM. The 100/2.8 Macro is listed as EF100mm f/2.8 Macro, with no USM mentioned. So it looks like its this 100mm macro which is not fully compatible:

The current non-L 100mm macro should be fine:

Quote from: Canon
All of Canon’s current range of EF and EF-S lenses are compatible with the Dual Pixel CMOS AF system.

It's expensive because of the combination of carbon fibre constuction and exceptionally high profit margins.

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