August 29, 2014, 01:26:13 AM

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Messages - rs

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Lenses / Re: Another standard zoom advice topic
« on: August 28, 2014, 04:40:01 PM »
I'll probably get a knee-jerk reaction for saying this, but if you can somehow stretch to both afford and can carry it, the mk II version of the 24-70/2.8 is smaller, lighter (805g vs 950g), and has noticeably better IQ. If cost and weight is an issue, my next port of call would be a white box Canon 24-105.

« on: August 28, 2014, 07:31:19 AM »
If you use a non reporting TC, even a old 10D will autofocus at f/8 with some lenses.  Others do not work.  I've tried in numerous bodies and lens combinations over the years.  The TC you use also makes a huge difference, some work better than others.

Again beside the point, though.

The claims by some here are that AF simply won't work in the circumstances we're discussing: I'm saying that I've got a shed-load of actual personal experience - over a number of years, bodies and TCs - that flies directly counter to the "facts" being stated by these individuals.

Of course there's an element of compromise to this, and of course some combos work better than others; but the fact is that they work, despite these authoritative claims that they simply can't.

The only body I couldn't get to AF at all with a TC and my 100-400mm was the 40D; in fact, I believe I was the first person to break this news, on DP Review.

But others could get AF with that body and a TC using the 400mm f/5.6 prime, so - even there - the blanket "can't work" claim was utterly bogus.

All I'm really saying is this: don't take it as gospel that your camera won't AF at f/8 simply because some "expert" on the internet says it won't. Try it yourself
Before you get too critical of other peoples opinions here on this thread, just take a moment to read what they're saying. It's all identical to your findings, just some are saying the glass is half empty while others are saying the glass is half full. It all amounts to the same thing. AF can and does work with some/many f8 lens/TC combos and f5.6 capable bodies, but it can't be guaranteed to work reliably with every f8 lens/TC combo and every f5.6 body in every typical shooting scenario.

« on: August 27, 2014, 07:03:55 AM »

Will a 60D do?

If there is sufficient of light then then 60D might do that, just as the 7D or the 70D could do it over there. there is however no guarantee that you can do it from Canon, as it is not build in in the design of the camera. I am not aware which firmware this even might block, but I think Canon could have done this. Did you look at the quality of your link to digital picture? even in the center the sharpness is gone when you compare the 560mm with the 400mm.
This combo is f8 wide open at the long end. Due to the pixel density of the 60D, diffraction starts to limit resolution at f6.9, so smaller apertures don't have much scope to tidy up the already quite bad resolving power of that lens/TC combo in the centre.

There are no rumours of the hardware in any of the existing Canon crop bodies being capable of autofocusing at f8, so as far as I know there is no possibility of a firmware update for a 60D, 70D or 7D to allow for this feature. There's nothing stopping you from manually focusing it, trying out AF through live view, or even taping over the extra pins on the TC to trick the camera into attempting autofocus.

However f8 autofocus on the 7D mk II is a distinct possibility, even if the rumoured pixel density will mean apertures smaller than f6.6 will run into resolution limiting diffraction.

« on: August 27, 2014, 05:50:56 AM »
Yep, fully aware of that, but it's beside the point: I'm letting people know that despite suggestions to the contrary, both the 7D and the 70D will work in circumstances which some on here have stated they won't work in.

But you need to use then a third party extender for fooling around the body concerning available max aperture. My opinion, the Canon extenders still deliver the best quality on Canon lenses. So, I would like to see a photo of the 100-400 + 1.4 extender on the tele end and taken on a 7D or 70D, as I have my question about IQ at that moment.
Will a 60D do?

« on: August 27, 2014, 03:06:06 AM »
Just some Real World experience to add to the mix: the 7D will AF usefully quickly for bird photography at f/8 (eg Canon 100-400mm and taped or non-reporting 1.4x TC) off the central AF points. Use it on the peripheral points, and it's actually not bad at all.

For example - 600mm, handheld, (Kenko non-reporting 1.5 TC), peripheral AF point on the bird's eye.

And another.

The 70D (mine, and that of at least two other users that I asked to test this) will AF at f/8. Again, it's not lightning fast, but it works.
The hardware may be capable in certain situations of working, but if the central AF point doesn't function, or the reliability doesn't meet the manufacturers stringent testing standards, it's much simpler for them to simply mask out this borderline operation via the firmware.

« on: August 26, 2014, 05:53:02 PM »
Almost all DSLR's autofocus only functions when the lenses aperture wide open is f5.6 or brighter. It's for the same reason that slow lenses make the split prism focus screens on old manual focus SLR's go black.

Being able to AF, even with limited AF functionality with lens combos as slow as f8 was the preserve of the 1 series for canon shooters until the 5D3. Think of a 600/4 with a 2x TC, or a 100-400 with a 1.4x TC.

Your 20D focus issues will be unrelated. It will only attempt to AF with f5.6 lenses (or brighter). If it consistently misses, that's likely down to a problem (calibration or otherwise) with your lens or body.

Pricewatch Deals / Re: Placing an order today (I think) - need advice
« on: August 26, 2014, 03:23:30 AM »
The 70-200 II is optically close to perfection, and takes TC's remarkably well, even the 2x. However, the 1.4x and 2x mk III TC's won't physically mount together. You'll need an extension tube (so you'll likely lose infinity focus), and the camera won't get the correct info about focal length or aperture reported to it.

Also the optical degradation will be significant. You'd be better off using the 2x TC and cropping in post if such a narrow AoV is required.

I guess one big question is:
Which will give better resolution, putting the 70-200 2.8 mk2 on a 70D body with the 1.6x  20.2MP crop sensor APS-C, or putting a 2x Mk3 teleconvertor on the 70-200 2.8?
Not quite a 6D or a 70D, but a 21MP FF (1Ds3) and an 18MP crop (60D), both with the lens and TC you requested:

Lenses / Re: A New Pancake Lens? [CR1]
« on: August 23, 2014, 07:38:50 AM »
The 44mm flange distance makes a non retrofocus (ie pancake) 24mm EF or EF-S lens unlikely.

EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 22, 2014, 05:58:48 PM »
I've seen the results from the 800E, and they are stunning in terms of detail out-of-camera. For nature photography, you don't really need an AA filter.
What's the point in a camera which can produce (in your eyes) better pictures in one particular scenario, while other scenarios are plagued by a design flaw?

Also, what about any nature shots with repeating patterns around the sampling frequency? Uniform vegetation such as some grasses or leaves, bird feathers, animal hair etc?

What you gain is false information. False sharpness. False detail.

Low pass filters are used in all forms of sampling to avoid aliasing. Aliasing is nothing but artefacts. If you can't excite aliasing due to oversampling, there is no gain to be made by avoiding a low pass filter.

Computers have for some time used anti aliasing to improve the percieved resolution of displays - this avoid the jagged edges, false details and create more realistic renderings.

EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 22, 2014, 05:44:32 PM »
Lens electronic MF
Is this some poorly translated way of saying lenses with electronic manual focus such as STM lenses and the 85L will have manual focus all the time, rather than just while the metering is on? While that would save a lot of annoyance, that could potentially waste a lot of battery power unless they find a way of waking up the system with any detected rotation of that focus ring.

EOS Bodies / Re: Are These The EOS 7D Mark II Specifications?
« on: August 22, 2014, 05:39:34 PM »
the 7D MK II will have continuous AF like camcorders. It's not necessarily required on their higher end cine slrs, and it's the reason the # AF points has increased. Does that not align with the new video features and is a result of the new sensor features. That would put it ahead of everything else?
The number of focus points refers to the amount found on the AF chip, which is completely bypassed when the mirror is up for videoing. That's where DPAF comes in, which has substantially more than 65 AF points - 20.2 million to be precise. There is no increase in numbers here over the 70D. Processing power is the big sticking point, and that's where the 7D mk II could gain.

65 AF points, all cross type, is a big gain for any situation where the mirror is down.

Technical Support / Re: Question regarding sensor size and image quality
« on: August 22, 2014, 07:39:59 AM »
Another difference is typically the FF body/lens combo will have the optics stopped down more, potentially getting it nearer to optical perfection than the smaller sensor equivalent.

... unless you're shooting macro, with the ff I end up well in the diffraction zone in no time so actually the my crop 60d produces the better images than my shiny new 6d. Plus with macro, to get the same fov crop & ff the latter will have a lower effective f-stop at close distance, so the iso advantage is no good either.
Quite correct - when shooting macro, those rules fall apart.

Technical Support / Re: Question regarding sensor size and image quality
« on: August 22, 2014, 07:31:11 AM »
If FoV and DoF are identical between the different sized sensors, both scenarios will be capturing the same total amount of light as the entrance pupil will be stopped down to be of an identical size.

It could be simply the dynamic range and tonality - to take things to an extreme, you can stop down a FF DSLR to mimic the DoF of a compact camera with the same FoV, yet the compact will be much more likely to have the highlights blown out and an overall flat look to the image. Obviously this difference reduces if the sensor sizes are more similar, but a differences remain.

Another difference is typically the FF body/lens combo will have the optics stopped down more, potentially getting it nearer to optical perfection than the smaller sensor equivalent.

EOS Bodies / Re: How do reds come out in your 5d3 ?
« on: August 13, 2014, 05:16:56 AM »
Intensive reds are often out of gamut.

The easiest way is to select ProPhoto color space and not smaller as Adobe RGB or S-RGB and chose to  work in 16 bit mode.
Then manual  proof the color values ‚Äč‚Äčinto a smaller color space as Adobe RGB and later on  convert to the destinated color space as Adobe RGB or S-rgb.
There are no profile  instructions how a RGB   conversion properly is done between a larger color space and a smaller. Therefore proofing  in the colors in to a smaller color space  is the best way to go with out color clipping in red. But first, make one copy in S-RGB and one in Prophoto and you  immediately  see the difference in the shades of red  in  Prophoto due the much larger color space.
Good luck

The 5D3 can only write a file in Adobe RGB or S-RGB. Do you have experience then that a photo taken in Adobe RGB and uploading in LR or PS gives better result in Prophoto color space? Where would that supplemental detail come for your Prophoto color schema?

It can only write jpegs in those colour spaces. Raw files are taken and stored with the only colour space constraints being that of the sensor itself. The raw converter will then apply a colour space which may or may not introduce further gamut restrictions.

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