What I REALLY want from Canon Digital....

Olympus 9-18mm f/4.0-5.6 M.Zuiko Digital ED

05/18/2005 12:42:51 PM · #1

I want a 1x lens extender...

Yes you read that correctly...

A 1x extender. One that is EXTREMELY bright and as close to "0" for light loss. Then I could permanently leave this on my Canon 20D and screw ALL my other lenses into it. This would allow me the advantage of a removable lens system and give me the nice dust free life of my old Olympus E-20!

What do you think? Good idea? is it feasible? could Canon construct such?

jonr

Olympus OM-D E-M5

05/18/2005 12:48:39 PM · #2

That's unpossible!
Unless you want to stick to macro photography only...

Btw, the dustbuster on E-1/E-300 actually works...

PaulMdx

Canon EOS-1D

Canon EF 70-200mm f/2.8L USM

05/18/2005 12:48:49 PM · #3

I suspect Canon can do it, but I don't really see their motive. They're lowering the quality of their lenses to reduce dust issues that I would say are relatively minor.

Maybe in very harsh conditions it might be worth it for pro's, but having seen how they treat their equipment normally, I wouldn't say they seem particularly concerned about dust!

05/18/2005 01:00:25 PM · #4

"Unless you want to stick to macro photography only..." - jonr

That doesn't make sense....right now people use extenders mostly for telephoto work. Why would such limit you to only macro work?

"I suspect Canon can do it, but I don't really see their motive. They're lowering the quality of their lenses to reduce dust issues that I would say are relatively minor." - PaulMdx

They already do this for the extenders. However, since no magnification is necessary they could make it extremely bright (like a single extra lens element in a lens). I bet they could engineer such to be the brightest lens/glass.

As for the loss of quality. How many people add a UV filter or what not to keep their lens safe? This would not be much different. It'd be to simply keep the camera body equally safe.

I think a LOT of people would go for it! And it's not like you'd HAVE TO USE IT... it'd just be available for those of us who'd like the added protection.

- Jason

Plexxoid

Sony 24-70mm F4 Vario-Tessar T* FE OSS

05/18/2005 01:10:43 PM · #5

I think just putting a peice of glass in front of the mirror or right behind the lens mount would do.

Bear_Music

Samsung Galaxy S24 Ultra

05/18/2005 01:11:08 PM · #6

Originally posted by theSaj:

"Unless you want to stick to macro photography only..." - jonr

That doesn't make sense....right now people use extenders mostly for telephoto work. Why would such limit you to only macro work?

By definition, an extender "extends"; an extender without glass is a "macro tube" and moves the lens physically further from the film plane, allowing only close-in focusing, i.e. "macro" focussing. A tele-extender has glass in it to compensate and magnify the image.

I suppose what you are suggesting is an extender with "negative compensation" glass, physically extending the lens and then returning the projected image to what it would have been otherwise. I don't think this is possible, but I don't really know. Certainly any thin extender with plain glass would have the effect or moving the lens out beyond infinity-focus range.

Robt.

Bear_Music

Samsung Galaxy S24 Ultra

Sony 24-70mm F4 Vario-Tessar T* FE OSS

05/18/2005 01:12:04 PM · #7

Originally posted by Plexxoid:

I think just putting a peice of glass in front of the mirror or right behind the lens mount would do.

The tolerances are too tight for that though. There's no extra space in there to do this.

Robt.

Plexxoid

05/18/2005 01:14:50 PM · #8

Originally posted by jonr:

That's unpossible!
Unless you want to stick to macro photography only...

Not "unpossible", but then I'm no optics expert. Additional optics (large and extremely sharp) would be required to essential subtract milimeters. Unfeasible, yes, impossible--probably not.

Edit: What Robt said.

Message edited by author 2005-05-18 13:16:13.

05/18/2005 01:15:39 PM · #9

"Certainly any thin extender with plain glass would have the effect or moving the lens out beyond infinity-focus range." - bear_music

Yes, the 1x extender would compensate....hence, it'd be a 1x extender (as opposed to a macro ring)

Plexxoid

Canon EF 70-200mm f/2.8L USM

05/18/2005 01:19:11 PM · #10

Originally posted by bear_music:

Originally posted by Plexxoid:
I think just putting a peice of glass in front of the mirror or right behind the lens mount would do.

The tolerances are too tight for that though. There's no extra space in there to do this.

Robt.

I think if Canon moved the sensor closer to the back of the mirror that'd allow more space in front of the mirror for a thin peice of well-coated glass. Could actually be beneficial to quality.

Edit: What I mean is that by moving the sensor closer to the mirror, they could move the lens mount further from the mirror.

Message edited by author 2005-05-18 13:20:26.

PaulMdx

Canon EOS-1D

05/18/2005 01:22:19 PM · #11

Originally posted by Plexxoid:

I think if Canon moved the sensor closer to the back of the mirror that'd allow more space in front of the mirror for a thin peice of well-coated glass. Could actually be beneficial to quality.

How would putting another piece of glass in front of the sensor be beneficial to quality?

colda

Nikon D800

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

05/18/2005 01:23:36 PM · #12

Or why not just put a piece of protective glass directly on top of the sensor itself? ;)

05/18/2005 01:24:56 PM · #13

you'd still get dust inside the body which would still land on that protective glass sheet and still be difficult to clean.

Where as a 1x extension lens could be cleaned as any normal lens.

soup

Canon EF 17-40mm f/4.0L USM

05/18/2005 01:25:39 PM · #14

don't change lenses while the camera is on...

jonr

Olympus OM-D E-M5

Olympus 9-18mm f/4.0-5.6 M.Zuiko Digital ED

05/18/2005 01:29:33 PM · #15

Well that is interesting. I'm no optics expert, but when I think more about it, it should be possible.
Lower than 1x extenders are possible, but a 1x extender? Why not? A 0.625x EOS extender would make every Canon lens work like on full-frame. And I belive it would be brighter too, if I understood some lens guy on dpreview.com correctly. 24-70 f1.75? :)

wgoodey

05/18/2005 01:44:32 PM · #16

Originally posted by colda:

Or why not just put a piece of protective glass directly on top of the sensor itself? ;)

it already has one. although it's meant to protect the sensor from damage, not from getting dust on it. and keeping a lens on the body doesn't guarantee that dust won't get in, it just makes it a little less frequent.

Canon PowerShot Pro 90 IS

05/18/2005 01:55:34 PM · #17

"it just makes it a little less frequent."

True,...but much less frequent....

And with people spending $20-$50 for cleanings. Or $100+ on a brush...it seems the lens at a $200-$250 extender price would be a good alternative.

I also think the idea of 0.6x extender might be interesting. If designed to counter the 1.6 crop of the 20D. But, my thought is that the only ones who would likely need such would be professionals. Who will probably just buy the pro 1D line (which I believe all future units will have a 1x focal factor.

coolhar

05/18/2005 02:41:29 PM · #18

There are lots of little changes that Canon, or any other camera maker, could make to their DSLR designs that would cut down on, or eliminate, the dust issue. I think it is Olympus that puts a small piece of sticky tape inside the camera body so that loose dust particles that land on it stay on it. Putting a layer of optically-neutral & easily-cleanable glass somewhere in front of the sensor, or in fromt of the mirror, would be another solution. Running a brief burst of opposite-polarity current thru the sensor at start-up to reverse the static attraction might be possible. With the resources that a company like Canon or Nikon could bring to bear, you have to think that if there was the will to do so, they would find a way resolve the issue.

Market leaders with such a big share of sales tend to become complacent. At least Olympus is trying to address the issue.

kyebosh

Canon EF 80-200mm f/2.8L

05/18/2005 02:57:05 PM · #19

- teleconverters are often used in macro photography as wellas other forms of photography.

- simply putting clear glass inback of the lens will possibly cost infinity focus.

- dust is not that big a problem in 95% of cases. Don't worry so much.

- There is a huge debate on UV filters on expensive glass because of image degrigation.

05/18/2005 05:04:06 PM · #20

Originally posted by kyebosh:

- teleconverters are often used in macro photography as wellas other forms of photography.

- simply putting clear glass inback of the lens will possibly cost infinity focus.

But if neither of these are issues with current 1.4x and 2.0x extenders - than they should not be so with a 1x extender either.

riot

Canon EOS-1D Mark IV

Helios 40-1 85mm f/1.5

05/19/2005 10:09:05 AM · #21

And what about when you get dust on your protective glass cover or extender thingy? It's hardly solving any problem, it's basically doing what the antialiasing filter does but the glass is more vulnerable... and any dust would be further from the sensor and hence would make larger softer blotches rather than small easily cloned out specks.

All that is not to mention the cost of producing a relatively tiny piece of glass that would have to maintain the quality produced by much larger lens elements in the lens itself which you pay a fortune for anyway... to produce equivalent quality on a much smaller piece of glass takes even more precise workmanship because every microscopic imperfection makes much more difference.

Also, i'm not entirely sure, but i suspect that if you try to compensate for the extension tube effect with optical elements (in the 1x extender) so you keep infinity focus, you'll instead lose the equivalent portion of your close focus range.

riot

Canon EOS-1D Mark IV

Helios 40-1 85mm f/1.5

05/19/2005 10:13:51 AM · #22

Originally posted by kyebosh:

simply putting clear glass inback of the lens will possibly cost infinity focus.

Not at all, this is how rear drop-in and screw-on filters work.