The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

New gig, four thirds micro

scott kirkpatrick

Well-known member
telecentricity...

Such a lot of misinformation is shared about telecentricity. First of all, modern rangefinder lenses are far from symmetric. Consider the pair of rangefinder wideangles below. The 1960-ish Canon 19/3.5 on the left extends 19mm in back of the mount, and only 12 mm in front of it. The front element is more than twice the size of the rear element, but at least the exit pupil must be behind the mount frame. The 2000+ Zeiss 21/2.8 on the right extends only 12 mm behind the mount frame, but extends about 50 mm out in front. As a wild guess, the exit pupil might be 30-40 mm away from the image plane. (it takes an optical bench to find out these things; they don't seem to publish the information.) All of the currently manufactured Leica M lenses are similarly much longer than their focal lengths, at least up to 35mm focal lengths and probably beyond as well. The extra length is being used to accomplish the degree of correction now offered.

I think it was corrected far above in this thread, but light rays coming from a lens cannot all be parallel. No focused image would result.

scott
 

etrigan63

Active member
I'd love to see a nice rangefinder using this lens standard - just give me an optical viewfinder as well. Sensor quality on 4/3 format is of course critical for demanding use, but I understand it is decent today and will get better over time. This is an interesting development.
A shoe mount viewfinder could be added at little cost. The issue becomes framing if you use a zoom lens. Not knowing how many shoe contacts there are on a μ-4/3 body but if the lens mount has two extra contacts, could be transmitting focal length data for use in an electronically linked optical viewfinder. Such coolness would probably be a Leica-class add-on goody.

I for one will look at the Leica version.
 

Lars

Active member
A shoe mount viewfinder could be added at little cost. The issue becomes framing if you use a zoom lens. Not knowing how many shoe contacts there are on a μ-4/3 body but if the lens mount has two extra contacts, could be transmitting focal length data for use in an electronically linked optical viewfinder. Such coolness would probably be a Leica-class add-on goody.

I for one will look at the Leica version.
I have to say I prefer a (good) built-in viewfinder to an external one. The whole idea of a compact system fails a bit if you have to attach a viewfinder. And I prefer an optical viewfinder to an EVF (still getting by without reading glasses but it's only a matter of time).

Sure I too look forward to seeing where Leica goes with this u43 standard. But what is the likelihood of an affordable Leica system? I think more interesting is that u43 is an open standard where multiple vendors can market lenses as well as bodies.
 

Martin S

New member
I hope that this interesting concept of a smaller, thinner camera includes some type of VIEWFINDER!!! The thought of using a camera like this thru Live View only is not very appealing to me. I still find it unnatural to hold a camera out in front of me to see the image, compose, and make the image.
Using some of the larger, current 4/3 lenses in this awkward position seems unrealistic at best, and unwieldy at worst.

Just my opinion.


Martin
 
D

derek324

Guest
Not necessarily 'in front' if the LCD panel is articulated, and allows to use a camera at waist level. This makes it rather natural, easy to compare composed picture with reality, and allows more discreet photography (very important in some countries!). Having said that nothing prevents designers from including a viewfinder - this is what the outline in dpreview seems to be showing.

I hope that this interesting concept of a smaller, thinner camera includes some type of VIEWFINDER!!! The thought of using a camera like this thru Live View only is not very appealing to me. I still find it unnatural to hold a camera out in front of me to see the image, compose, and make the image.
...
 

Steen

Senior Subscriber Member
How open a standard is Four Thirds actually, can anyone join, or what does it take to become a member ?
I have always wondered why Zeiss doesn't participate with Four Thirds lenses.
 

Jorgen Udvang

Subscriber Member
I believe anyone can participate, but don't to what degree they have to follow the concept with regards to lenses being telecentric etc. While the lenses from Olympus and Panaleica are all designed for the concept, Sigma's are just lenses from their standard lineup with a new lens mount.

There are also suppliers that have signed up, but not yet participated. Fuji is one. It would be interesting to see a 4/3 camera and some Fujinon lenses from them. A Micro 4/3 camera should be well suited to replace their long sequence of bridge cameras.
 

Jorgen Udvang

Subscriber Member
So it's only the lens which is open standard? I thought Riley was referring to the entire system including the sensor/camera size.
The whole system, including lens mount, lens to camera communication, sensor size and format etc.) is an open standard, but I used the lens example, since that is the only part that has been supplied from anyone outside the Olympus/Panasonic/Leica sphere. Those three apparently cooperate so closely, that it doesn't really matter if it's an open standard or not.

Should Sigma decide to launch a 4/3 DSLR (something that would have given the Foveon sensor a big boost), that would obviously change things a bit, and even more so if Fuji does the same.

But the concept is probably of most interest for suppliers who "fit in", who has something that isn't there already, but lack their own complete system.

Surprisingly, image stabilisation is not a part of the standard, and even though the IS in the PanaLeica lenses will work on an Olympus body, not all of the functionality will be available.
 

jonoslack

Active member
The whole system, including lens mount, lens to camera communication, sensor size and format etc.) is an open standard, but I used the lens example, since that is the only part that has been supplied from anyone outside the Olympus/Panasonic/Leica sphere. Those three apparently cooperate so closely, that it doesn't really matter if it's an open standard or not.

Should Sigma decide to launch a 4/3 DSLR (something that would have given the Foveon sensor a big boost), that would obviously change things a bit, and even more so if Fuji does the same.

But the concept is probably of most interest for suppliers who "fit in", who has something that isn't there already, but lack their own complete system.

Surprisingly, image stabilisation is not a part of the standard, and even though the IS in the PanaLeica lenses will work on an Olympus body, not all of the functionality will be available.
Hi Ben
Hmm - it isn't really 'open standard' as in the Linux development community - more like a consortium, but the idea is that everyone can join, and there are clear definitions for sensor size / lens mount / lens telecentricity.

Incidentally Jorgen - you're right about image stabilisation - but it's worth mentioning that the Olympus E5xx (eg 520) and the E3 both have very good 'in body' stabilisation - it's only the E4xx series which don't
 

atanabe

Member
Interesting format/concept! The flange to film distance of the micro 4/3 is 20mm, Leica M ~26mm, adapters M to micro 4/3????? With a 6mm gap, maybe a reader for 6 bit codes?
With a 2x crop factor and EVF with focus confirmation you will get a 270mm f3.4 APO out of the 135, throw in vibration reduction and you may have something there.
 
A

alfred_uy

Guest
Hi,
There is a very informative interview on this topic with Masakazu San from Olympus at fourthirdsphoto.com
Regards,
Alfred
 

jonoslack

Active member
Interview with Ogawa Haruo at dpreview.

Hi there - I couldn't find the interview on fourthirdsphoto.com, but here is one one dpreview.

Part 3 has some mention of making it compatable with m mount lenses which is interesting (I still find the concept of my 75 'cron as an f2 150mm to be rather exciting!).

Link to Dpreview thread
 

Jorgen Udvang

Subscriber Member
Interview with Ogawa Haruo at dpreview.

Hi there - I couldn't find the interview on fourthirdsphoto.com, but here is one one dpreview.
It's gone. It was a translation of an interview they had found somewhere else, so they may have bumped into some copyright issue.

It's the same one on dpreview :rolleyes:
 
Top