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Sorry guys, but it's probably not a glass prism

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David Kilpatrick

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Because the leaked specifications clearly state it has a new INTERNAL COATING. That mean's its mirror prism, with improved reflective surfaces. You can not coat glass internally.

Now of course they could have got the wording wrong, but the other specs which used the 'roof mirror pentaprism' term (Sony's language for a porroprism) made it unlikely it would be a solid glass prism, and this one just backs that up.

So don't get annoyed and disappointed if they turn out to have made a brighter, better mirror prism and not fitted a glass prism.

David
 
--
fjbyrne
 
If the prism is as you suggest a porro-type David I do hope Sony have sealed it adequately. While I have nothing against mirrors per se, I have experienced major problems with another maker's 35mm SLR cameras when working in harsh atmospherics.

For example working for several months around volcanicly active landscapes, geyser or mud pool country, where not one, but three cameras' hollow mirror prism assemblies became heavily discoloured as sulphurated gases in the atmosphere gained access. No knowing how, or why, but obviously sealing of the mirror box housing was deficient.

The manufacturer quickly replaced one, then a second unit. Didn't have the heart to send the third back. Just bought no more of that unit.

XE 5 kept going throughout those years and environs without missing a beat. (Still does)
--
Sonnarman
 
That's the funniest joke you've come up with so far!

I believe that what you are referring to was the "Spherical Acute Matte" coating, which is also featured on the KM 7D.

Did you miss the mini-site?

It stated Pentaprism, nothing less. It even had a blurb about it, and a comparison with the Alpha 100...

Alpha 100
Mirror
95%
0.83x
20mm
-2.5 to 1.0m-1

Alpha 700
Pentaprism
95%
0.9%
25mm
-3.0 to +1.0m-1

(This matches the KM 7D in every respect.)
--
Stuart / the Two Truths
http://www.flickr.com/photos/two_truths/
http://two-truths.deviantart.com/gallery/
 
David Kilpatrick said:
Because the leaked specifications clearly state it has a new INTERNAL
COATING. That mean's its mirror prism, with improved reflective
surfaces. You can not coat glass internally.
Click to expand...
From I can remember of the microsite before it was taken down, I gather that they use improved AR coatings on some of the surfaces. I presume it is for the AE sensors and perhaps the one adjacent to the viewscreen.

Cheers,
Daniel.
 
I'm pretty sure it's a pentaprism. However I was a little disappointed to see it's still only a .9x magnification and 94% coverage. On an APS-C camera, that still adds up to a relatively small viewfinder. Especially in light of the D300's 100% view at .94x magnification.
--
Good luck and good light.
http://www.kennedyphotography.net
 
Have seen it clearly on the sony site when is was there ... comparing the alpha100 (mirror) with the alpha700 (pentaprism).

Sorry, but this time you were wrong ;)

Stephan
 
Yes. you're right. In the comparison it clearly states "pentaprism". One thing I didn't like in the comparison was the statement that the PC sync terminal was a Sony/Minolta proprietary terminal. Now I'll have to buy an adapter to use as a "standard" terminal. Oh well.
--

' You don't have to have the best of everything to get the best out of what you do have'.

 
mezman said:
I'm pretty sure it's a pentaprism. However I was a little
disappointed to see it's still only a .9x magnification and 94%
coverage. On an APS-C camera, that still adds up to a relatively
small viewfinder. Especially in light of the D300's 100% view at
.94x magnification.
Click to expand...
It is 0.9x with 95% magnification.

The D300 costs over two-fifths more than the Alpha-700!

The nearest competitor to the Alpha-700 is the Canon 40D...
That is 0.95x with 95% magnification.

However; the 40D is 1.6x crop rather than 1.5x crop. That gives you approximately the equivalent of 0.89x, which is smaller than the Alpha-700.

--
Stuart / the Two Truths
http://www.flickr.com/photos/two_truths/
http://two-truths.deviantart.com/gallery/
 
That doesn't make much sense.

The PC sync terminal on the KM7D is industry standard, there is nothing proprietary about it. The flash shoe, on the other hand, is.
Bill Force said:
Yes. you're right. In the comparison it clearly states "pentaprism".
One thing I didn't like in the comparison was the statement that the
PC sync terminal was a Sony/Minolta proprietary terminal. Now I'll
have to buy an adapter to use as a "standard" terminal. Oh well.
--
' You don't have to have the best of everything to get the best out
of what you do have'.

Click to expand...
--
http://avicdar.com (my portfolio - please visit!)

-----
KM7D
Sony-Zeiss 135 1.8
Sony-Zeiss 85 1.4
Minolta 50 1.7
Sony 35 1.4G
Tamron 28-75 2.8
Minolta 70-210 F4
Sigma 15-30
 
I makes great sense if you have a terminal like I have on 2 Olympus cameras that only fit their proprietary cords. Get out in the world more?
--

' You don't have to have the best of everything to get the best out of what you do have'.

 
Two Truths said:
mezman said:
I'm pretty sure it's a pentaprism. However I was a little
disappointed to see it's still only a .9x magnification and 94%
coverage. On an APS-C camera, that still adds up to a relatively
small viewfinder. Especially in light of the D300's 100% view at
.94x magnification.
Click to expand...
Click to expand...
Two Truths said:
The D300 costs over two-fifths more than the Alpha-700!

The nearest competitor to the Alpha-700 is the Canon 40D...
That is 0.95x with 95% magnification.

However; the 40D is 1.6x crop rather than 1.5x crop. That gives you
approximately the equivalent of 0.89x, which is smaller than the
Alpha-700.

--
Stuart / the Two Truths
http://www.flickr.com/photos/two_truths/
http://two-truths.deviantart.com/gallery/
Click to expand...
True, no doubt about it the D300 costs more then the A700. But I was hoping for a little better viewfinder. That's been one of my biggest complaints with my move to digital is how tiny the viewfinders are, making manual focusing nearly impossible.

--
Good luck and good light.
http://www.kennedyphotography.net
 
Yeah, I get out in the world just fine, thanks.

The previous post stated that the PC sync was a proprietary KM/Sony PC sync. My point was that the KM7D had a standard sync, therefore to state that the PC sync on the A700 is 'proprietary KM/Sony' makes no sense, since KM never had a proprietary PC Sync.

Get it?
Bill Force said:
I makes great sense if you have a terminal like I have on 2 Olympus
cameras that only fit their proprietary cords. Get out in the world
more?
--
' You don't have to have the best of everything to get the best out
of what you do have'.

Click to expand...
--
http://avicdar.com (my portfolio - please visit!)

-----
KM7D
Sony-Zeiss 135 1.8
Sony-Zeiss 85 1.4
Minolta 50 1.7
Sony 35 1.4G
Tamron 28-75 2.8
Minolta 70-210 F4
Sigma 15-30
 
Two Truths said:
It is 0.9x with 95% magnification.

The D300 costs over two-fifths more than the Alpha-700!

The nearest competitor to the Alpha-700 is the Canon 40D...
That is 0.95x with 95% magnification.

However; the 40D is 1.6x crop rather than 1.5x crop. That gives you
approximately the equivalent of 0.89x, which is smaller than the
Alpha-700.
Click to expand...
Thanks for the explanation. I never knew how you were supposed to compare those vf figures from different cameras.

--
Henry Richardson
http://www.bakubo.com
 
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