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Messages - herbert

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1
EOS Bodies / Re: Canon 6D Wifi Linking with iPhone 5
« on: December 07, 2012, 01:19:28 PM »
What is the tethering range for the WiFi signal? I'm interested in the feature but it would be useful to know it works reliably over at least 20 meters (line of sight).

Thanks.

2
EOS Bodies / Re: 7D Firmware officially announced
« on: June 28, 2012, 09:35:54 AM »
well, what I am really missing is the possibility of a quick change between a single-shot and fast multi-shot.

There is the AF.Drive button on the top of the camera:

- Press the AF.Drive button
- Spin the thumb wheel to select the mode
- Carry on shooting (the mode will be set when you press the shutter button to continue)

No need to go into the quick menu.

3
EOS Bodies - For Stills / Re: 5D Mark III vs. 1D Mark IV
« on: May 06, 2012, 01:59:54 PM »
The reviewer of the digital picture, used the 5DIII for sports with 300 2.8 and 400 2.8 lenses and says that the focus hit rate was impressive. This guy has good experience with the 1 series cameras so I am sure he knows what he is talking about.

I also remember him saying that the hit rate for the 300/400 f2.8 mark II was less than for the mark I when he reviewed the new 300 and 400 lenses. This was with the older 1-series bodies (1Ds3/1D4) since the 5D3 was not out at the time. He did speculate that the 1Dx might be the solution to this issue.

If he tested the 5D3 mainly with the new super telephoto lenses (and it makes sense to do so) then the new focus system on the 5D3, and 1Dx, could be better in this case due to the co-development of the lens and body to be a perfect match. The lenses do have chips inside for focus control.

So if you are planning on buying a new super telephoto too then the line between the 1D4 and 5D3 is more blurred.

4
EOS Bodies - For Stills / Re: 5D Mark III vs. 1D Mark IV
« on: May 06, 2012, 11:07:13 AM »
Here is another difference not yet mentioned:

Quote
Lens drive speed: Because of its higher voltage battery, the 1D Mark IV can supply an initial burst of power to select L-series USM telephoto lenses (limited to EF super telephotos) that drives them twice as fast as normal for the first second of operation. The 5D Mark III can't do that because its battery is lower voltage, and also because the camera body is not designed to accept higher voltage even if it was available.

http://www.ronmartblog.com/2012/03/canon-5d-mark-iii-unboxing-first-report.html

This is only from specification. I do not know if the difference is noticeable in the real world. I own neither camera but I am currently doing a lot of reading about the potential upgrades for my 7D which from my perspective is limited when used for distant nature photography in low light.

5
When expressing chroma subsampling ratios the 4:2:2 doesn't refer to primary colours as G:R:B, it's Y:Cb:Cr which refers to Luminance (Y) and two colour difference components Blue Difference (Cb) and Red difference (Cr)

I think that they are one in the same (G:R:B and Y:Cb:Cr) in this application, but I'm not certain.

The 4:2:2 is a type of chroma sub-sampling.

Since the human eye is more responsive to brightness than to colour it is possible to save space when storing an image by storing more brightness values than colour values. This is done by converting the RGB colour space to Y:Cr:Cb. The colours (Cr,Cb) are then sampled less than the brightness (Y) when the image is saved.

Note that the Y:Cr:Cb colour space can be converted back to RGB (it is simply a different 3-dimensional representation of the same data). Missing Cr:Cb values are filled in from surrounding values and then each pixel is converted back. This is done when viewing the movie.

Check out the Wikipedia article that has a few picture showing how the image stored in different sub-sampling schemes looks:

http://en.wikipedia.org/wiki/Chroma_subsampling

Quote
The subsampling scheme is commonly expressed as a three part ratio J:a:b

J: horizontal sampling reference (width of the conceptual region). Usually, 4.
a: number of chrominance samples (Cr, Cb) in the first row of J pixels.
b: number of (additional) chrominance samples (Cr, Cb) in the second row of J pixels.

From this you can appreciate the 4:2:0 is worse than 4:2:2 since the former will only change colour every other horizontal line. Both will change colour every other vertical line. The holy grail is 4:4:4 since that does not throw any information away. If also takes up more space.

The second factor in quality is how many bits are used to store the data. Canon DSLRs use 8-bits (values from 0-255). The Cinema cameras use 10-bit (0-1023) or 12-bits (0-4095) so get a lot more gradation of tone. This also takes more space.

I believe the combination of sub-sampling, bit-depth, image size (e.g. 1920x1080) and frame rate (e.g. 24/s) are all combined to create a bit-rate for the movie. This is how many numbers are passed through the system per second. It is this final number that states the overall quality of the system and also the type of storage media requirements involved.

6
Lenses / Re: Very long lenses could become redundant...........??
« on: April 26, 2012, 07:14:47 AM »
A lens is basically capturing a cone of light from the object and focussing it back to a point. So the wider the cone you capture the more light you have to form the image. The need for this is very apparent when there is not much light, e.g. the Hubble space telescope has an aperture of 2.4 meters and focal length of 57.6 meters (a 57600mm F24).

Bigger lenses will make a better image with the same sensor with the same exposure time because they have more light.

On the other hand what you are stating is that a better sensor will make better images with the same lens because it more accurately captures the same amount of light.

(Note that the usual caveats about imperfections apply. If sensors/lenses are not perfect then comparisons between combinations are not straightforward.)

If you want the best image then you should use the best lenses and sensor. So the requirement at the top level for large lenses will remain.

However if you want images to a certain quality with a restricted budget then a better sensor is more economical than bigger lenses.

Also, as previously mentioned, depth-of-field is important in photography. Lens aperture effects depth of field but must always be considered in the context of equivalence (see http://www.josephjamesphotography.com/equivalence/). Bigger lenses may be the only way to get the desired image look.

7
Third Party Manufacturers / Re: Zeiss Distagon 15 f/2.8 ZE Official
« on: March 16, 2012, 12:19:12 PM »
Image comparisons are available on The Digital Picture:

Samyang 14mm @f2.8 vs Canon 14mm @f2.8
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=769&Camera=453&Sample=0&FLI=0&API=0&LensComp=454&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

Nikon 14mm @f2.8 vs Canon 14mm @ f2.8
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=628&Sample=0&FLI=0&API=0&LensComp=454&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0
(The Nikon is so bad it has me confused. Must be an old lens.)

Nikon 14-24mm @ f2.8 vs Canon 14mm @ f2.8
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=615&Sample=0&FLI=0&API=0&LensComp=454&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

Zeiss 15mm @ f2.8 vs Canon 14mm @ f2.8
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=794&Sample=0&FLI=0&API=0&LensComp=454&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0

The Nikon 14mm is bad.
The Nikon zoom is better.
The Samyang is good.
The Canon is good but lots of vignetting.
The Zeiss is better (has less distortion and CA).

Zeiss = $2950
Canon = $2199
Nikon 14-24mm = $1997
Nikon 14mm = $1529
Samyang = $399

Only the Zeiss supports filters.

The Samyang seems like a great way to start in the wide angle world.

The comparisons actually surprised me. There is a lot of talk about how Nikon is better at wide angle. These images do not show that to my eye.

I also looked at f8 and the results are similar but less pronounced.




8
Lenses / Re: New Lenses Coming [CR3]
« on: February 23, 2012, 02:11:41 PM »
That pancake lens announcement is really good news.   May mean that the 600mm f4.0 Pancake prototype may finally see the light of day:

If Canon can make one of those then I'll be waiting for the Flux Capacitor and a Telepad as additional extras. Price estimate $3500.

9
Lenses / Re: Recommendation 70-200/2.8+2x vs 100-400 f/4-5.6L ?
« on: February 15, 2012, 02:57:25 PM »
This thread has discussed a lot about how good the images from each lens can be. This seems to be a mute point given that all of them can produce good images.

I find a better differentiator of equipment is how many images you miss. No one ever talks about the ones that got away. This will then favour the lenses with IS for low light (allowing more shutter speed options) and responsive and consistent autofocus. In this respect I would expect a more modern lens to perform better. However it requires a lot of field testing and not a few sample shots of a test chart/static subject. Anyone have any thoughts on the keeper rate under difficult shooting circumstances for the 70-200+2x verses the 70-300L or 100-400L?

I'd be very annoyed if I kept missing moments because the lens I use was not consistent and accurate.

10
Lenses / Re: Recommendation 70-200/2.8+2x vs 100-400 f/4-5.6L ?
« on: February 15, 2012, 11:59:34 AM »
According to the review and the ISO charts on TDP, the 1.4III see very limited IQ loss when mated with the 70-200 f/2.8 IS II vs. the 70-300L

http://the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=6&API=1&LensComp=738&CameraComp=453&SampleComp=0&FLIComp=4&APIComp=0

I don't know Pix, the 70-300 looks pretty significantly sharper to me.

smirkypants- you are right
I agree, the 70-300 is at it's sharpest at 300 f/5.6. 

The original link had the 70-200 + 1.4 @ f4. When they are both at f5.6 it is a bit more even:

http://the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=687&Camera=453&Sample=0&FLI=6&API=3&LensComp=738&CameraComp=453&SampleComp=0&FLIComp=4&APIComp=1

The zoom+extender shows less CA and distortion. However it is softer, particularly in the midframe.

I recently poured over these sample crops when deciding whether to buy the 2x extender for my 70-200 f2.8 or to buy the 400mm f5.6 for extra reach when birding. I decided on the 400mm f5.6 prime as a dedicated birding lens. However I do already have the zoom so this is less relevant to the OP.

I think that as Neuro demonstrated with his images either option will be able to deliver good images. The images will be far worse than the difference between them with slight mistakes during your image capture and workflow. I'd probably choose the 100-400 for its great versatility. Having to switch in and out an extender would get tedious. Get the lens, hone your technique and enjoy your photos.

11
EOS Bodies / Re: 1D X high res samples just appeared
« on: February 07, 2012, 06:11:29 AM »
Is the sample image from the 600mm mark II any better than you would expect from the mark I?

12
Lenses / Re: How much!?
« on: November 04, 2011, 12:28:41 PM »
The ONLY real difference in these lenses is the focusing mechanism and manual iris. That's it.

I was under the impression that cinema lenses exhibit no focus breathing.

http://en.wikipedia.org/wiki/Breathing_(lens)

Thus when you change focus your field of view is the same. From the price I think we can assume that this is a lot harder to manufacture than optical sharpness in our well known EF still lenses.

Plus can you put a price on bokeh? Maybe Canon have tried to.

13
EOS Bodies / Re: Rain Photos - Wet Camera Photos/Stories
« on: November 02, 2011, 03:53:34 AM »
Shot with strobe flash on a 7D to pick up falling raindrops.

14
Canon EF-S and EF-M Lenses / Re: Canon 15-85mm f/3.5-5.6 IS USM
« on: October 19, 2011, 02:14:06 PM »
I don't shoot this as my main lens but whenever I put it on I am reminded of what a great piece of glass it is.



Canon 7D, 50mm, f11, 1/640s, ISO 100

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