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Messages - CR Backup Admin

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Lenses / Re: EF 300 f/4L IS II Patent
« on: February 16, 2011, 12:41:44 AM »
Canon still includes examples with pellicle mirrors in some of their patents, and they haven't released one for many years.  Many patents are filed to protect a technology and prevent someone doing something clever with it.

Companies are often blind to inventors ideas, the company I worked for turned down a patent by a employee that covered a method to deal with the Y2K situation.  They signed over the rights to him, and he had it patented.  When it became a very popular solution, he popped up with his patent and cleaned up.

Software & Accessories / Re: shutter actuation software for Mac
« on: February 16, 2011, 12:32:31 AM »
Canon dropped the ability to check this. 

They offer a free "System Developer Kit" which contains the core software that many third parties use under license to readout the 40D, etc.  The capability to read the newer cameras is not included, so the only current way is to send it into Canon.

I am not for or against square sensors, there is no doubt that they would be more versatile. 

My father just passed away at 93, and I, being the holder of many thousands of old family photos decided to scan them all.  Much to my delight, I discovered many old 120 format negatives as well as more modern 620 square negatives.  I have a Epson photo scanner, and the large negatives allowed me to make copies directly without resorting to old wrinkled or faded prints.  The negatives sometimes had a few flecs of dust, so I had to clean the scanner frequently, but were basically in original condition.  The quality of the images from what was probably a fairly simple fixed lens consumer camera is amazing, I did not expect them to be so sharp.

There were also a few very old 35mm negatives, but they were scratched and very difficult to get a good scan, even with a lot of tweaking of the scanner settings, and post production. These were 1940's negatives, and looked pretty primitive.

Just when I thought I was through after 2100 images, I found another large stack of 620 negatives.  I also have my own 35mm images to scan from over 40 years ago.  We have several photo albums and a large number of old polaroid prints.  The color ones have faded badly, and may not be worth scanning.  I am very disappointed with this, since I will lose a lot of family photos if I can't recover them to a reasonable quality.

It makes me want to buy a medium format digital, but, It would not really be a practical walk around camera compared to my 5D MK II.  I've been thru the develop your own film and print the photos back in the 1960's.  I don't have the patience to do that any longer.

Here is a Canon white paper about manufacturing sensors.  You can do the math about cost, but it will jump a huge amount.

As you can see, a 8 inch wafer holds 200 APS-C sensors and yields about 180 good ones.  only 20 FF sensors fit, and the yield is incredibly low.  I'd extimate 14 33 X 33 sensors would fit with even lower yield.

Undoubtedly, the yield is better than it was in 2006, but the wafers likely cost more as well.  Its also easy to see why round sensors don't make economic sense, we use rectangular images almost everywhere, and to get a equivalent 24 X 36 out of a round sensor requires one larger than 36mm in diameter at a huge cost.

Lenses / Re: EF 300 f/4L IS II Patent
« on: February 15, 2011, 02:09:03 PM »
I respect your thoughts, I was looking at reliability in just the opposite way. 

A pizoelectric crystal is extremely reliable, and if the moving lens group in the IS were eliminated, the reliability might be greatly increased.   One of the big hits lenses took in reliability was with the introduction of the moving IS elements.  This is not to say that they are horribly unreliable, but they are a weak link.

I really do not expect to see a lens that uses the principle soon, but it would be interesting to see what actually happens to reliability.  We do not have enough information about the actual construction to do a accurate analysis, and early implementations will likely be improved on later.

Lenses / Re: 24 - 105 mm f/4 L IS II
« on: February 15, 2011, 01:45:00 PM »
Ken Rockwell is not to be taken seriously, neither is Canon Rumors, its for fun. 

In reality, a good photographer can work around the shortcomings of almost any decent lens.  The real result is the affect of the image on the viewer, not the technical aspects.

Lenses / Re: Your lenses wishlist for 2011.
« on: February 15, 2011, 01:30:35 PM »
I may have to set my 10-22mm to the 20mm setting and see what I think ...

Always a good idea if you have a zoom covering the range of prime lens(es) you're considering.   8)

Another way to see what you like is to review your existing images.  Adobe Lightroom will let you look at various combinations of camera and lenses and see how many images were taken at various focal lengths, shutter speeds, and a ton of other things.  I did this when considering whether to get the 24mm 1.4 or 35mm 1.4.  I had twice as many images at 35mm, so thats what I bought.

I found a older Tokina 17mm prime locally on Craigslist for $150.  Its not a crop lens, and not f/2.8, but it fills the need for ultra wide on my Canon 5D MK II and was actually good enough that I sold my Canon 17-40mm L.

Lenses / Re: 24 - 105 mm f/4 L IS II
« on: February 15, 2011, 01:16:32 PM »
When I saw the Nikon 24-120 I thought that most Canon users won't like such a high zoom lens. I don't like a one lens for everything with quality penalty strategy. Considering this lens launched 5 years after the Canon 24-105, it seems to be a bit inferior to the Canon equivalent.

The Nikon 24-120 VR was a "D" lens and launched in 2003.  It should not even be mentioned in the same breath as a Canon 24-105mm L.

It was considered to be horrible, and made the 10 worst lenses of all time list.

That is why they replaced it in 2010, no one knowledgable wanted it.  The new lens (AF-S 24-120 mm f/4G ED VR ) is a G lens and much better, it has a ultrasonic focus motor, but optically is not anything to brag about, particularly edges and corners.

I certainly would not consider trading one for my 24-105mm L.

Canon General / Re: Photographer Profile: Drew "Rukes" Ressler
« on: February 15, 2011, 12:13:26 PM »
I'm all for training, but training is a two edged sword.  You might learn what your teacher knows, but if he has it wrong, so do you. 

Experience, like most endeavors is where you really learn, and you can teach yourself if you really want to learn.

I received a engineering degree from a large University, but when I went to work, the training really began, I was in no way ready to take on real world engineering responsibilities.

Canon General / Re: Photographer Profile: Drew \
« on: February 14, 2011, 11:50:54 PM »

"Any formal training in photography?
None at all."

It shows.

This is your first post.  Post some of your images.  You have no credibility as a expert as it stands.

Lenses / Re: EF 300 f/4L IS II Patent
« on: February 14, 2011, 11:12:18 PM »
This lens has elements whos refractive index is controlled electrically.  Its not a conventional lens by any means.  I have no idea as to the practicality of mass producing them, but, it is a very interesting idea, one that we all have hoped would come.

Although it gives a 300mm f/4 lens as a example, it is a new type of IS that might appear in any lone telephoto lens.  Perhaps one of the new super teles.


JPO and INPIT are not responsible for any
damages caused by the use of this translation.

1.This document has been translated by computer. So the translation may not reflect the original precisely.
2.**** shows the word which can not be translated.
3.In the drawings, any words are not translated.


[Claim 1]
It is an optical instrument which has an optical system,
A shake detection means which detects deflection,
An electro optics element which constitutes said a part of optical system and from which internal refractive index distribution changes with the electro optic effects according to voltage impressed, An optical instrument having a driving means which impresses voltage to said electro optics element so that an image shake by deflection detected by said shake detection means may be reduced.
[Claim 2]
The optical instrument according to claim 1, wherein refractive index distribution inside said electro optics element is unsymmetrical to an optic axis of said optical system.
[Claim 3]
The optical instrument according to claim 1 or 2, wherein said electro optics element shows the secondary more than electro optic effect.
[Claim 4]
An optical instrument of any one description of three from Claim 1, wherein this optical instrument has a vibration control means for reducing an image shake by deflection detected by said shake detection means apart from said electro optics element.
[Claim 5]
An optical instrument of any one description of four from Claim 1 having a photosensitive element which records an object image formed of said optical system.

[Translation done.]

•Patent publication number 2011-27864
◦Publishing, Feb 10, 2011
◦Filing, Jul 23, 2009
•Implementation example 1
◦Focal length f=294.00mm
◦8. 24 ° Angle of view
◦Image circle 43. 28 mm
◦Lens length 245 mm
◦Back focus 86. 2 mm
•When shooting in runout
◦Human image stabilizer is approximately 0.1 to 10 Hz (low frequency)
◦Of a tripod is 4-35 Hz
◦Number of Hz etc vehicle camera-several hundred Hz (high frequency)
•For the image stabilizer of the conventional correction technology in mechanical movement, high-frequency fluctuations and cannot compensate
•Electro-optic effect if 100 Hz-kHz up to meet
•Patent technology
◦High-frequency blur to correction
◦Using electric Optics (electro-optic crystals)
◦Vary depending on voltage (electric) refractive index (electro-optical effect)
◦Asymmetric distribution of refractive optical axis.

Lenses / Re: EF-S L Lenses
« on: February 14, 2011, 07:13:42 PM »
Many people are already confused by the difference between EF-S and EF lenses
:D  With full names like EF 70-200 mm f/2.8 L IS II USM, EF 100-400 f/4.5-5.6 L IS USM, or EF 70-300 f/4.5-5.6 DO IS could anything about a lens name be confusing?   

Maybe they should be something like "Tamron AF 70-300mm f/4-5.6 SP Di VC USD"  :)

Lenses / Re: Canon EF-S 18-55mm 1:3.5-5.6 IS II
« on: February 14, 2011, 07:04:48 PM »
Wow, another FAIL from Canon. If they wanted to launch a new EFS they should have replaced the 17 55. any lens with  variable aperture is a FAIL. And that includes the new L 70 300. Whatever happened to the good old days of the 70 200 series...Gone, lost in the wake of the credit crunch...  :'(

Not all users can afford expensive lenses, thats why every camera and every lens maker has variable aperture lenses. We are talking a kit lens for a $700 camera kit, and you think it should be a $1500 lens?

EOS Bodies / Re: T3 Sensor - question...
« on: February 14, 2011, 07:00:27 PM »
Resolution of a lens / sensor combination is going to always be much lower than a person would expect.  The system resolution is equal to the product of the MTF of the individual components.

If your lens has a mtf of .7 and your camera 0.7, the result is 0.49, much lower than either one.  The way to increase the system resolution is to increase the mtf of the components.

Increasing the megapixel count in a camera increases its mtf.  noise reduction, noise, and AA filters as well as other factors including the firmware also affect the mtf of the body.

This was exactly the same issue with film, each layer of the emulsion has a mtf and the total mtf of the film is the product of the three, then multiply that by lens mtf, and very quickly, the system mtf drops off sharply.

A printer or a computer monitor screen drops it a whole lot more.  Its a struggle to keep the resolution up.

Lenses / Re: EF-S L Lenses
« on: February 14, 2011, 12:56:22 PM »
Many people are already confused by the difference between EF-S and EF lenses, not to mention E lenses like the TS-E tilt and shift.

It would be better not to further confuse things by having a EF-s L lens.  Perhaps a different designator for luxury lenses might work.  I'm not going to suggest one.

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