October 31, 2014, 11:58:01 AM

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Messages - rs

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Lenses / Re: New 400mm DO II not suitable for converter?
« on: September 21, 2014, 04:02:14 AM »
Canon have provided pretty impressive MTF graphs with both TC's, so I'm putting money on it working with them.

EOS Bodies / Re: 7D Mark II Video Tested By Gizmodo
« on: September 18, 2014, 05:56:09 PM »
This is my take on it: That brick wall in the background of the first scene has some pretty heavy moire on the 70D; the 7D mk II and 5D mk III seem to be much better on that front. In terms of sharpness, in this test the 5D3 is better than the other two. When it comes to noise, the 7D2 appears to be between the other two, possibly closer to the 5D3.

EOS Bodies / Re: High ISO Samples from the Canon EOS 7D Mark II
« on: September 17, 2014, 05:05:45 AM »
I have a 550D and i see no difference at all.   :o

What difference are you expecting, exactly?

Quote from: pleasehelp
To be honest i wonder first and foremost that i see no difference at all after so many Sensor generations.

I mean is this already the end of what we can expect?
Is there only an ISO improvement from now on?

Well, assuming the 7DII sensor is basically similar to that in the 70D (minor tweaks), you're talking about one generation.  One.

Sorry im not up to date.

But that "generations" was of course in reference to my 550D.

Since my 550D, i bought 2010, nothing has happend?

Image quality in my compact cameras has made big steps forward.
When i compare images from my old P&S cameras to todays i immediately see a difference.

When i look at the 7D MK2 pics they look exactly like my 550D images.  ???
I don't understand what you're expecting to see? Resolution and sharpness are hidden at 1920 pixels wide, DR isn't an issue with lighting like that, and high ISO looks pretty impressive. Other than handling (which the pictures can't reveal), the way the scene is rendered is down to the lens.

Premium compact cameras are getting bigger sensors and faster lenses. This APS-C camera still has an APS-C sensor, and still has access to all the same lenses your camera does. What are you expecting?

Because actually, the link for the C lens in Maximilian's post is wrong.
Yes, sorry! Link was wrong,  c&p error.
And I just looked at the links quickly on my phone. Well spotted.

Why do the mtf graphs of the two different lenses look identical?  :o

EOS-M / Re: AF speed 40/2.8 vs 85/1.8
« on: September 11, 2014, 05:20:57 PM »

A little surprised the 85/1.8 is quieter than the 40mm.... isn't the STM supposed to be a quiet motor?
STM lenses make a high pitch noise, almost similar to a loud version of baldy shielded processor noise leaking into amplifier circuitry. Nothing like the volume of micro motors of older cheap lenses. It's almost completely silent, and great for video work. USM motors are silent to all intents and purposes, although there is typically the noise of components other than the motor - the internals of the lens gliding over each other etc. And of course there's the fairly abrupt torque as the AF system start/stops to achieve its fast focus acquisition speed. This is no good when it comes to slow, smooth video AF requirements as the USM system will go through a constant start/stop sequence.

So - for video with DPAF, STM is significantly quieter and smoother (both for focus smoothness and torque/recoil you feel as you hold the lens), whereas USM is a little quieter and typically much faster for images.

Easy answer.

1. 7d and 500mm f/4 is 800mm equivalent and f/5.6 equivalent like DOF capabilities and rendering the fore/backgorund.

2. 5d iii and 500+1.4 is 700mm f/5.6 mm lens

Nearly - the 1.6x crop makes a 500/4 equivalent to a 800/6.4 lens vs a 700/5.6 on FF with a 1.4x TC

So in reality, the 800/5.6 behaves much like a 1280/9 on crop, vs an 1120/8 on FF and 1.4x TC.

I'd also argue that the supposed 7D2's AF system would be focusing at f5.6, vs the 5D3 at f8 - that should be an advantage, plus the FPS is nearly doubled. As stated, there's more than the theoretical 1.3 stops difference in S/N between the 5D3 and 7D1, so the gains of the faster lens are more than lost. But this is the unknown quantity of the 7D2 - who knows what it's S/N is?

You do not want 800 for crop. Your subject will be to far away and the air between the lens and the subject will blow your IQ. Believe me. Even 600 is to long for crop sensor.

Depends upon what size object you're focusing on. If it's as small as the lens can frame, you're only 6m away from the object - no issues there with the amount of air. If the humidity, pollution and heat haze levels are favourable, 100m could be perfectly fine. And other times getting closer simply isn't an option, so starting off with a competent lens/body can't hurt, even if the conditions aren't the best.

Lenses / Re: DXOMark Reviews Zeiss Otus 85mm f/1.4
« on: September 10, 2014, 01:17:44 PM »
Has anyone noticed that the 'true' max apertures as indicate by the Tstop is nowhere near the manufacturers claim? The Zeis is closer to a f1.8 lens than f1.4 and the rest fare no better....

T value is not aperture value, an f1.4 lens is a "true" f1.4 if the apparent aperture diameter is focal length divided by 1.4. The T value relates to actual light transmission and is pretty much irrelevant with TTL metering stills cameras.

Aperture value is always lower than T (transmission) value because however good the glass is you always lose some.

Nothing is completely transparent - even the air inside the lens. And if you can see any reflections on any of the elements within the lens when peering through the end, that's light which hasn't made it through.

12mm for full fisheye coverage? Insane... 15mm is hella-wide as is with fisheye.
A typical fisheye at 15mm provides 180˚ coverage, corner to corner. Typically you can't get any wider than that without mechanical vignetting in the corners (as is the case with the 8-15 when zoomed below 14mm), or with a lens wider than 180˚ (some go up to about 185˚).

I believe the reason why this has a much shorter focal length is due to its projection - it is likely to be stereographic, which means it's much less obviously a fisheye. Most conventional fisheyes use a projection much closer to equidistant or equisolid, which tends to make the centre of the image bulge and the edges look all squashed. Stereographic looks much more natural. The centre is magnified much less, hence the typically shorter focal lengths to achieve the same angle of view.


If this does have stereographic projection as I suspect, I might well be very interested in this lens. Obviously this is also dependant on its price and optical performance.

Photography Technique / Re: Benefits of IS in fast shutter speeds
« on: September 10, 2014, 11:13:46 AM »
And what about IS while shooting in 200 mm range handheld with shutter speeds 1/2000 and faster?
In some scenarios, it's a must - as highlighted in my above post. Although in typical handheld scenarios at that length and shutter speed, it's only there to stabilise the viewfinder a touch, making composing and getting the AF points on the subject slightly easier. However, if you really prefer not to use it at such speeds, just turn it off.

Photography Technique / Re: Benefits of IS in fast shutter speeds
« on: September 10, 2014, 08:23:08 AM »
As well as all the great advice given above, please remember the rule of shooting a shutter speed of 1/focal length is just a general guide - there are many variables that affect the outcome. For instance:

What is the pixel density of your body, and how big do you want to reproduce the image? (A 6mp image printed at 6x4 is much less demanding of sharpness than a future ~40mp body used to produce huge wall art)
How steady are you hands?
How steady is the platform you're shooting from? (I quite often shoot sports from small motorboats, and IS is a make or break feature for that)
Is there ever going to be any wind that could catch the lens/lens hood?

In other words, situations could exist where even 1/2000th won't give you the results you want for a 200mm lens without IS - ignoring the fact that you might not be able to frame, let alone get the AF point to lock onto the subject.

If you can guarantee you'll only ever use the lens in lab controlled conditions, you'll be fine without IS.

Lenses / Re: Samyang 12mm F2.8 Full Frame Fish Eye
« on: September 10, 2014, 07:49:00 AM »
Would the focal length of 12mm, vs the 15mm of other diagonal fisheyes, mean it uses a different projection? The linked page says nothing about that.
I'm guessing that unlike a normal fisheye such as the Canon offerings (current and previous), this will be like the 8mm APS-C (1.5x crop) Samyang fisheye which has a stereographic projection. 8mm x 1.5 is 12mm, so it's a good fit.

EOS Bodies / Re: 7DII full frame?
« on: September 08, 2014, 11:45:22 AM »
well last rumor heard from a good informed source close to canon told me.... canon will introduce exchangeable sensors.

there will be no phase detection AF anymore because it´s obsolete.
DPAF II is now faster and way better.

so maybe the 7D MK2 Standard comes with APS-C and the Edition model comes with a FF sensor.

btw: Doug confirmed it was a placeholder text.
Yeah, DPAF has definite speed advantages over standard phase detect AF for DSLR's, and that big mirror and shutter blocking out the light to the sensor where DPAF is situated at the time of acquiring focus doesn't matter at all  ::)

Are these sensors you talk about to be available in a user replaceable canister?

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