October 21, 2014, 08:31:34 PM

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Messages - traveller

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16
EOS Bodies / Re: Patent: Canon EF 100-400 f/4.5-5.6 DO
« on: May 24, 2014, 10:22:07 AM »
Unless Canon have made a breakthrough, then DO whilst an interesting concept, is not ready for use in mainstream lenses like the 100-400mm replacement. An important update such as this simply has to prioritise superb optics over light weight, not to mention the price of DO lenses in relation to their conventional counterparts!

17
A much needed pair of lenses for Canon.

Let's now hope that the 16-35 f/4L IS is a big improvement on the 17-40 f/4L, especially in the corners.

The price of the EF-S 10-18 f/4.5-5.6 IS STM is great, a perfect complement to the 18-55 and 55-250 IS STM lenses, so long as it is optically up to scratch. A few fast wide angle to normal primes would help Canon stave off the mirrorless competition ;-)

18
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 01, 2014, 06:13:44 AM »
Canon ... please stop f*rting about and just give me a higher megapixel camera !

My 21Mp 1Ds3 is six years old, tired and itching to be replaced.

We've waited long enough ...

I've got a friend in the same position: he likes the 1-series bodies and now wants to upgrade to higher resolution and better noise control. I believe that Keith Cooper over at Northlight Images is also waiting... Neither find the 1D X the right solution, as they are unwilling to spend the money on a camera that doesn't improve on the resolution they get from the 1Ds MkIII.

People assume that their needs are the same as everyone else's and that people who want a high resolution body would prefer a smaller camera. For some, this is indeed the case, but I also believe that there is a significant proportion of 1Ds owners that are happy with their cameras' configuration. How many of these will continue to wait if Canon further delays a replacement, and how many will be tempted to migrate to the likes of the Pentax 645Z? 


19
Lenses / Roger Cicala's initial Sigma 50mm f/1.4 Art results
« on: April 30, 2014, 06:46:34 PM »
He's done some multiple sample tests against the Zeiss Otus and Canon 50mm f/1.2L, though he isn't confident enough in his sample size to give too many definitive conclusions (he only tested seven   ;) )!

http://www.lensrentals.com/blog

20
What would be cool to see is the breakdown of the numbers of which lenses :)

EF 28-80mm f/3.5-5.6 (all variants) - 10 million
EF 28-90mm f/4-5.6 (all variants) - 10 million
EF-S 18-55mm f/3.5-5.6 (all variants) - 40 million
EF 75-300mm f/4-5.6 (all varients) - 10 million
EF-S 55-250mm f/4-5.6 (all varients) - 10 million
EF-S 18-200mm f/4-5.6  - 10 million
All others - 10 million

A touch harsh perhaps?  Maybe not ::)

21
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: April 30, 2014, 05:09:40 AM »

Surface area of FF => 864mm^2
32429/864=47.41

If they can only get 20 FF sensors out of that, they have about 58% losses. 

This is an 8 year old white paper and nobody mentioned these mistakes before?

That's very interesting if indeed that does translate to about 58% full frame sensor losses per wafer, even if it was 8 years ago.

I made a mistake (maybe Canon has a job offer ;-)), corrected it in my last post. It should be

Surface area of FF => 864mm^2
32429/864=37.5

If they can only get 20 FF sensors out of that, they have about 47% losses.

It isn't exactly 47% loss. It's 64% of the area is actually used to print FF sensors. If this diagram is any indication, then they actually ETCH exactly 24FF, or 80APSC on a single 200mm wafer:



The actual losses would be out these numbers...so accounting for defects and whatnot, actual FF yield would have to be less than 24, and actual APS-C yield would have to be less than 80. Assuming they actually get 20 FF out of 24, the loss is 16.7%.

That assumes that the article was clear about the size of wafer used to produce APS-C sensors...which it is not. Since a 300mm wafer can handle about 212 APS-C sensors, and since the article states that around 200 APS-C sensors are made from each wafer, it makes sense that Canon is manufacturing APS-C sensors on 300mm wafers, rather than 200mm wafers. Either way, they clearly have a higher yield off smaller sensors.

So the conclusion of this thread seems to be that (if this rumour has any truth in it) Canon are moving their full frame production to 300mm wafers? Could this also be an opportunity for them to move to a newer process generation?

22
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: April 29, 2014, 12:32:26 PM »
So with the Sony a7r, do the clipped corners affect the image in anyway? Surely not since no one has reported black corners. How does that work then? Is the entire sensor area not used then? That would mean in reality a sensor size slightly smaller than FF, prob negligible though overall?

If that's the case then perhaps a FF sensor could be squeezed into the M mount then with a tiny bit of cropping. Or Canon could make a completely new sensor that is almost FF in size and fits perfectly (seems unlikely in terms of maximizing profits).
The clipped corners aren't a problem because of the way light travels when leaving the lens - think of it as an expanding cone, so the image circle is physically smaller at the lens mount than when it hits the sensor.  Just look at the back of the EF 40mm f/2.8, the rear element is significantly smaller than a FF sensor:



OTOH, there may be issues with some lenses with a large aperture and an exit pupil close to the image plane (similar to the 'clipped' bokeh of the 85L wide open with close subjects).

Interesting points. Could this explain why Sony/Zeiss have so far steered clear of large aperture wide angle and telephoto primes?

23
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: April 29, 2014, 11:11:07 AM »
Thus either this rumor is a hoax (why would Canon not want to reduce the cost of sensors made for the top end?)...

Can I flip this around: why would the top end be the priority for reducing production costs? Surely the margins are tighter at the bottom?

I believe that you're thinking it wrong: ANY reduced manufacturing costs goes straight to the bottom line.

Sure, the lower end has a higher volume, but sometimes it is easier to reduce costs at the high end simply because people didn't bother too much about cost, with the argument that "it's high end, so our focus is quality, not cost", which ends up in a circular argument resulting in high cost.

Believe me, I speak from experience (sigh).

1. What yield improvement were you thinking of that is of no benefit to APS-C sized sensors?

2. If it is of benefit to APS-C sized sensors, why apply it only to full frame sensors? Surely you apply the technology that improves yield to the production line that has the highest production levels (i.e. APS-C), not the one with the lowest?

24
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: April 29, 2014, 10:13:10 AM »
Thus either this rumor is a hoax (why would Canon not want to reduce the cost of sensors made for the top end?)...

Can I flip this around: why would the top end be the priority for reducing production costs? Surely the margins are tighter at the bottom? Besides, I can't think of why a new production technology that improves yield wouldn't equally benefit APS-C sized sensor production costs.

I think that this whole rumour is based upon the "all cameras will be  full frame in the future" fallacy that we're now meant to buy into. If Canon are experiencing pressure from mirrorless in the APS-C market, then it's lenses that are more to blame than camera bodies.

So I think your first proposition is probably more correct:

Thus either this rumor is a hoax...


 ;)

25
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: April 29, 2014, 09:58:53 AM »
Not sure this can even be answered yet but if Canon came out with a full frame EOS-M version, would they need to change to a new lens mount as well? Could the EF-M still be used?

EF- M mount can't be used for FF unfortunately. Too small. Likely they'd create a mirrorless camera with the regular EF mount instead.

This is widely stated, but I can't see that the EF-M mount is much different in dimensions to the Sony E mount; I know that E mount is tight for full frame, but it is still possible. I'm struggling to find the technical specifications, but here's a comparison (assuming the scaling is correct) -measure for yourself:

http://camerasize.com/compact/#487,351,325,466,459,ha,f

EF-M is pretty similar to E-mount in its internal diameter and a bit larger than either X-mount or micro 4/3rds. We also know that the flange back distance is the same as E-mount (18mm, vs 44mm for regular EF).

I'm not saying that this proves EF-M is compatible with full frame sensors, nor that Canon would have any near term plans to produce a full frame mirrorless camera if it were, but it would be a bit strange if they happened to make it so similar in size to E-mount and it not be FF capable. They must have had some idea that Sony were interested in making a FF E-mount camera. I believe that FF probably is possible with EF-M mount, if nothing else then to cover that base for the future. Of course, Canon would never admit that now whilst it is still trying to push their FF DSLRs!

As for a mirrorless camera with an EF mount: it's possible but not with a reduced flange back distance, or they'd create all sorts of lens compatibility confusion!

26
Lenses / Re: Review: Sigma 50mm f/1.4 DG HSM Art Lens
« on: April 22, 2014, 02:39:22 PM »
This is a real bummer, as I rate AF consistency as one of the most important aspects of this type of lens. I've found that for the most part, missing focus is far more destructive to resolution than a few hundred line widths per pixel height difference in MTF50. Of course, this new Sigma 50mm and the Zeiss Otus are exceptional in that they are clearly far superior at large apertures to the conventional double-gauss designs.

The situation might not be so bad except that my camera's focusing screen (5D3) is pretty useless at showing depth of field at large apertures, so it's easy not notice the fact that the focus is off; this also makes accurate manual focus almost impossible below f/2.8.

27
Lenses / The-Digital-Picture Sigma 50mm f/1.4 "Art" lens review posted
« on: April 22, 2014, 09:39:42 AM »
Bryan has posted his review of the Sigma 50mm f/1.4 "Art"

http://www.the-digital-picture.com/Reviews/Sigma-50mm-f-1.4-DG-HSM-Art-Lens.aspx

The verdict:

"With excellent image quality and great design, this lens becomes the easy 50mm AF lens choice. AF consistency remains this lens' biggest weakness."

28
Lenses / Re: New TS-E Lenses for Photokina [CR2]
« on: April 21, 2014, 09:50:22 AM »
I can't think what "unique feature" would be useful on a tilt-shift... macro capability? IS wouldn't help much on lens that will be used with a tripod 90% of the time; maybe they've worked out how to get AF to work with tilt-shifts (but I doubt it)! Knowing Canon, perhaps they've incorporated defocus control  ;D

29
Street & City / Re: Street Voyeurism Continued
« on: April 11, 2014, 03:35:29 AM »
I see too much "street photography" that is either boring or that attempts to create interest through confrontation with the subject. Your shots, on the other hand really capture the moment without provoking it -great work! I particularly like the humour with the shop attendant and the mannequin, also the guy taking a picture of him and his family with a camera on a pole and the reaction of the bystanders.

30
EOS Bodies / Re: EOS-1D X & EOS-1D C Cold Weather Autofocus Issues
« on: April 04, 2014, 05:02:16 AM »
This is one of the "joys" of the internet age; whereas in previous years, not many outside of the select few would have know of this issue (or noticed it), now it will be splashed all over the web with accompanying howls of derision. Or perhaps it is leading to companies being more open with service notices: Canon seem to be getting better after being badly burnt by the whole 1D MkIII AF episode; Nikon are learning the lesson the hard way! Was Six Sigma always a myth?

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