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05-12-2013, 09:34 AM   #946
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QuoteOriginally posted by RKKS08 Quote
1) Change the path of light before it reaches the mirror. This affects sensor and VF.

2) Change the path of light between mirror and VF. This would affect VF only.
Item 1) is possible, with the SpeedBooster, et al., but wasn't what I was referring to. Of course, any such adapter would make the viewfinder brighter, but we would need to change the optics for the viewfinder to make it bigger (which would make it dimmer).

Item 2) is what I was referring to. I'm saying that if you have a hypothetical 33mm F/0.92 lens on APS-C, you can make the viewfinder as bright and as large as a 50mm F/1.4 lens on FF. The size and shape of elements 5/6/7/8 in the picture below might have to change, and 6 + 8 might likely be multiple elements, but the function would still be the same. In this thought experiment, the size of the mirror remains unchanged.









In practice, camera makers don't optimize viewfinders for F/0.9 lenses, or even F/1.4 lenses, so bigger, brighter viewfinders are the province of full-frame cameras.

If you want to have some real fun look through a MF viewfinder. Truly awesome.

05-12-2013, 09:55 AM   #947
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QuoteOriginally posted by thibs Quote
Please no politics, it will again degenerate very quickly !
QuoteOriginally posted by bossa Quote
I doubt that he's personally responsible for the fact we've just had the hottest week in May for 100 years..
I was only being sarcastic. In another discussion I would gladly share my views about climate change (or the actual lack of it).

QuoteOriginally posted by Digitalis Quote
Though you do have to admit - politicians have contributed a considerable amount of hot air to the environment...
Indeed. They shouldn't have need for central heating at the capital building!

And all of their senseless carrying on in which they waste our tax dollars could be documented with the new full frame 64 megapixel DSLR that Pentax will be releasing later this year.
05-12-2013, 10:07 AM   #948
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QuoteOriginally posted by Raffwal Quote
Now that we've finally come to the long awaited question of the difference between Holland and the Netherlands, here you go:

https://www.youtube.com/watch?v=eE_IUPInEuc
Very nice! Thanks for clearing that up for me, it really helps to eliminate the confusion.

There was one error though.

New Holland is not a place, it is a tractor. New Holland tractors used to be Ford tractors, but now they are New Holland tractors, and have little, if anything to do with Holland (or the Netherlands.

05-12-2013, 10:10 AM   #949
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QuoteOriginally posted by rvannatta Quote
I'm not sure earthshaking things are needed in the line. I do wish they would deliver on the roadmapped converter modern enough
to actually support autofocus.
A set of extension tubes that support autofocus and other lens functions would be nice too!

05-12-2013, 10:12 AM   #950
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QuoteOriginally posted by monochrome Quote
Oh now I understand. So that's why the global average temperature hasn't changed in 15 years, despite all the dire hockey sticks. What a load of crap.

Tell the Chinese and the Indians to stop burning coal. We'll burn natural gas and in five years we'll be exporting crude oil since we can't use all that we produce. We're already exporting raw gasoline for the same reason.

The whole thing is anti-capitalist jealousy - an interestingly ironic position on a Forum devoted to spending thousands of dollars on what amounts to wasteful ephemeral entertainment, demanding that a certain company produce certain products at whatever risk of loss to themselves there might be so that we can pursue our selfish pleasures. /rant.
Sure. Gas and diesel is running $3.50 to $4.50 a gallon and we have such a surplus that we have to export it.

I want my money back!
05-12-2013, 10:21 AM   #951
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QuoteOriginally posted by tclausen Quote
Yes, but that's probably waaay too detailed for Racer X 69 this early in the morning

All I need to do is visit one of the many "coffee" shops they have there, and smoke a bit of the "product" that is served there.

05-12-2013, 10:32 AM   #952
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QuoteOriginally posted by ElJamoquio Quote
Item 1) is possible, with the SpeedBooster, et al., but wasn't what I was referring to. Of course, any such adapter would make the viewfinder brighter, but we would need to change the optics for the viewfinder to make it bigger (which would make it dimmer).

Item 2) is what I was referring to. I'm saying that if you have a hypothetical 33mm F/0.92 lens on APS-C, you can make the viewfinder as bright and as large as a 50mm F/1.4 lens on FF. The size and shape of elements 5/6/7/8 in the picture below might have to change, and 6 + 8 might likely be multiple elements, but the function would still be the same. In this thought experiment, the size of the mirror remains unchanged.









In practice, camera makers don't optimize viewfinders for F/0.9 lenses, or even F/1.4 lenses, so bigger, brighter viewfinders are the province of full-frame cameras.

If you want to have some real fun look through a MF viewfinder. Truly awesome.
I'm under the impression that the only real way of making the viewfinder bigger and bright is to increase the size of the mirror. After all, if you want more light you need to reflect more light into the pentaprism. No?
05-12-2013, 10:39 AM   #953
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QuoteOriginally posted by Racer X 69 Quote
There was one error though.
They pronounced "Curacao" wrong at 2:01.

Curaçao - Wikipedia, the free encyclopedia

"Curaçao (pron.: /ˈkjʊərəs/ KEWR-ə-sow"

05-12-2013, 10:39 AM   #954
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QuoteOriginally posted by IchabodCrane Quote
I'm under the impression that the only real way of making the viewfinder bigger and bright is to increase the size of the mirror. After all, if you want more light you need to reflect more light into the pentaprism. No?
You need to reflect more light - but you can do so by concentrating the light, which is what large-aperture lenses can do.

An APS-C camera with a 33mm F/0.92 lens has the same amount of light in a smaller area than a FF camera with a 50mm F/1.4 lens. So you can use that light to have the same amount of brightness and the same amount of area; but with the APS-C setup you'll need to 'diverge' the light more.

If sensors were enormously expensive we'd be going to shorter, faster glass and APS-C sized sensors. The opposite is true, glass is more expensive than larger sensors.
05-12-2013, 11:06 AM   #955
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QuoteOriginally posted by Racer X 69 Quote
Very nice! Thanks for clearing that up for me, it really helps to eliminate the confusion.

There was one error though.

New Holland is not a place, it is a tractor. New Holland tractors used to be Ford tractors, but now they are New Holland tractors, and have little, if anything to do with Holland (or the Netherlands.
Did ya have to post an image of one of their cheaper tractors? :P
05-12-2013, 11:10 AM - 1 Like   #956
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QuoteOriginally posted by Phosphene Quote
Did ya have to post an image of one of their cheaper tractors? :P
What? Half a million dollars isn't enough?
05-12-2013, 11:32 AM   #957
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@ElJamoquio

Sorry, but to me it seems your concept will not change the shortcomings of APS-C view finders in respect to size and brightness, as you are using the same amount of light that would reach the APS-C sized sensor. Whatever optics you would put in this "cropped" light path, would not change the amount of light. Additional optics could just make the view smaller and brighter, or bigger and darker.

However, my suggestions would probably also not help. I had only occasionally followed the discussions on dpreview some months back, as it seemed not to bear any relevance for my photographic attempts.
Only just before writing this post I a had a look at the speedbooster "white paper", and after doing this it seems my ideas are not mirroring the speedbooster concept. Condensing the light on the sensor/VF side means in fact changing the focal length, which is not what I had in mind. It would make the picture brighter, but magification factors of the sensor and the VF picture would not match anymore.
05-12-2013, 02:10 PM   #958
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QuoteOriginally posted by Racer X 69 Quote
All I need to do is visit one of the many "coffee" shops they have there, and smoke a bit of the "product" that is served there.
You mean that you didn't do so already, before posting in this thread?

I heard in the radio here, that some place in the US legalized this "product" already...Denver, Delaware or something (I think it started with a D...) so you'd not have to even get a passport....?
05-12-2013, 02:38 PM   #959
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QuoteOriginally posted by tclausen Quote
You mean that you didn't do so already, before posting in this thread?
No. I have a commercial driver's license, and am subject to random drug and alcohol tests. And marijuana is on the list of prohibited substances they test for.



QuoteOriginally posted by tclausen Quote
I heard in the radio here, that some place in the US legalized this "product" already...Denver, Delaware or something (I think it started with a D...) so you'd not have to even get a passport....?
Colorado has had medicinal marijuana for some time now, California and Rhode Island have "looked the other way". Alaska decriminalized possession of small amounts long ago.

Washington and Colorado voters passed legislation to legalize recreational use last fall. Washington lawmakers are sorting out the details of licensing dealers and taxing sales, Colorado lawmakers are watching, and the federal government is poised to arrest ans incarcerate everyone who violates federal law, as it is still a controlled substance.

Either way it goes I will be ready to document the proceedings with my new full frame Pentax camera, due out this summer!
05-12-2013, 05:34 PM   #960
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QuoteOriginally posted by Racer X 69 Quote
Sure. Gas and diesel is running $3.50 to $4.50 a gallon and we have such a surplus that we have to export it.

I want my money back!
Price is a function of global demand and supply, independent of whether we in the United States have excess supply of product to sell into the global market.

At least we're finally getting back some of the money we've exported in exchange for product since 1973.

Don't even get me started on farm products, or putting food in our gas tanks for no reason other than to enrich ConAgra.
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