Old Canon DSLR

[jbcohen]

I have an old Canon EOS Digital Rebel XT and would like to get the old manual for it.  Does Canon keep copies of old models?

[tallrob]

"Another benefit to the crop series of camera is less expensive lenses as it can use any lens Canon makes where the 6D can not."

I would not necessarily consider that an advantage.  After all it would be better to get a Rebel and spend the money on a better lens.  I would however say that the crop sensor does use the better part of any lens you put on it since it's cropping out the edges and corners.

[ebiggs1]

And this is one of the reasons so much confussion abounds with the term "crop sensor".

      "...  the 7D (and all other DSLRs with a APS-C sized sensor) "crops" the image."

It does not crop anything.  It never did and never will.  The difference is in the angle of acceptance of the lens.  All lenses waste some portion of their AOA because they all produce circular imagaes.  The sensor is square so some is lost to whatever sensor you have.  So, I guess it means all cameras are "crop-sensors".

Most people would consider the larger choice of lenses an advantage.  If you don't so be it.  But the bottom line is the 6D and 5D series users don't have that option at all.  It is, however, all about choices and what fits you best.

[tallrob]

Hey, man, with all due respect you really need to get over it. If we're going to use the term, which you yourself do too, then we have to concede that one way of looking at it is that the standard or typical image circle thrown by a lens is "cropped" more drastically than on a full frame sensor camera, OR the size of an APS-C sensor is simply a "crop" of a full frame, OR that you can achieve the equivalent angle of view of the APS-C image from a full frame image by cropping it. Any or all of these is true. So to say "it does not crop anything" is just not true. Chill out about it. You seem really defensive.

And I can't speak for "most people" (I don't know why you think you can), but I was just stating my opinion. Again, chill.

[Skirball]

---

@tallrob wrote:

And I can't speak for "most people" (I don't know why you think you can), but I was just stating my opinion. Again, chill.

---

Good luck.  I've been trying to convey the same message to him for some time now.  I found it best to just sit back and laugh at his nonsense.

Edit: Ok, I lied.  I can't help but comment on his nonsense.

[ebiggs1]

"Hey, man, with all due respect you really need to get over it."

I agree with everything you say but nevertheless the terminology is incorrect.  And, yes, I do use the term exactly as everyone else does.  I am guility as charged.  Also, I don't mean to sound defensive just trying, maybe poorly, to set the true facts about a crop camera.  I must get asked the same question dozens of time by beginners not understanding why their new Rebel crops the picture.  And why some yo-yo on forums like this one keeps calling it a crop camera like it had ebola.

And with all due respect to to you too,  I am not likely to get over it.  Sorry.

[tallrob]

I'm not sure what you expect to happen when you and everyone else keeps using the term.  It seems like you're setting yourself up for tons of arguments.  Logically, if one sensor is called "full frame", as it hails from the 35mm era, then a smaller sensor termed "cropped" is derived from cropping the full frame.  Any way you slice it (yep that's right), it is what it is.  Beginners need to do their research and learn lots of new terms.  I've yet to hear a better way to describe the APS-C sensor in a way that allows for a mental picture of what's happening between lens and sensor.

So my suggestion to get over it is just an appeal to logic.  You seem like a reasonable guy.  

[John_]

Thank you all for the information on this subject. Another novice question Im sure but for me a logical one pertaining to the physical characteristics of the lenses and sensors.

The lenses are round then why aren't the sensors round?

Or why aren't the new lenses square then since the sensors are ?

Adapters could be made so that people could still use their old lenses on square lens mounts.

Round sensors would be more efficient, perhaps it's harder to manufacture them ?

Im surprised at the temperature of a few responses of those who are just expressing their thoughts and experience. Luckily I'm to new debate lol !

[ebiggs1]

John_,

Sensors are not round because we as users expect to see and produce a square or rectangle photograph.

Round lenses make round images because they have to.  A camera has a square mask inside the mirror box that makes that round image look square.

This is the way it has been since all this started way way back when.  I suppose sensors could be made round or any other shape for that matter.

"I'm surprised at the temperature of a few responses of those who are just expressing their thoughts and experience. Luckily I'm to new debate lol !"

Don't be.  There is always some guy with a superiority complex that believes he must become the internet police. It is best for you to just ignor him.  I do and don't give him the satisfaction of a reply.

 I teach classes for Park and Rec and probably get asked the question about, what is a  "crop camera", more than anything else.  So you are not alone in this confussion.

The bottom line for you is to remember a "crop camera" does not crop anything.  It will produce exactly what you are seeing in it's viewfinder or LCD.  The rest is just numbers.

[John_]

ty ebiggs, thats interesting so if I am right the square mask inside the mirror box removes part of the circle outside of the square which I never see anyway though the veiwfinder or LCD.

And yes the lighbulb went off when you said we expect square pictures and produce square pictures !

I would guess manufacturers do not think it is worth the time or effort to produce a line of square lens cameras to go along with the square mask, square sensor and resulting square or rectangular photo.

[RobertTheFat]

---

@John_ wrote:

I would guess manufacturers do not think it is worth the time or effort to produce a line of square lens cameras to go along with the square mask, square sensor and resulting square or rectangular photo.

---

Except possibly as a full-employment project for optical engineers. I presume that the various aberrations and other screwy effects one might encounter near the corners of the lens would present a challenge.