My GF1 & some M39 Canon lenses

C

Coco

Newbie
Local time
10:05 PM
Joined
Mar 5, 2010
Messages
9
Finally my adapter arrived from Roxen, it didn't take long (8 days) but seemed like a life time when I was all excited... :)

Its finally here...so what do you think? (image sample soon)

Canon 1.8/35mm

original.jpg


Canon 1.8/50mm

original.jpg


Canon 1.9/85mm

original.jpg
 
Just one Q, what is the max aperture with the adapter, can you still use them open, or what is the new max aperture?


I saw that with the Oly OM adapter, you usually lose at least one f-stop...
and that is the main reason why I'm not convinced with the m4/3 system.

Thanks!
 
re_visible said:
Just one Q, what is the max aperture with the adapter, can you still use them open, or what is the new max aperture?


I saw that with the Oly OM adapter, you usually lose at least one f-stop...
and that is the main reason why I'm not convinced with the m4/3 system.

Thanks!
Click to expand...


Wide open all the way ...

.
 
re_visible, You can shoot wide open with any lens on any mount adapter. I think what you've read about OM adapter losing a stop is the same effect as long extension tubes losing stops (you have to compensate the exposure because the extra length of extension darkens the image) on Hassy or any other system close-up extensions.

When I had OM adapter, I shot wide open no problem but didn't think too much about compensating for the extension. Just shot as aperture priority.

I think with mount adapter for RF systems, you don't really have to think about losing speed because they are very short. If the adapter is for SLR mount, maybe you are losing some speed. It's like my 10mm tube won't change speed on hassy, but 21mm or 55mm does. But that doesn't mean that you can't use the wide open aperture.
 
Please correct me if I am wrong... But the change in aperture is due to the difference in size between 35mm frame vs. micro 4/3rds sensor size. What coelacanth is referring to is "bellows" correction due increasing the focal length for macro photography?
 
re_visible said:
Just one Q, what is the max aperture with the adapter, can you still use them open, or what is the new max aperture?


I saw that with the Oly OM adapter, you usually lose at least one f-stop...
and that is the main reason why I'm not convinced with the m4/3 system.

Thanks!
Click to expand...

There is no light loss as the lens is held at the correct distance from the sensor--these are not extention tubes. The aperture does not change.
 
buzzkill58 said:
Please correct me if I am wrong... But the change in aperture is due to the difference in size between 35mm frame vs. micro 4/3rds sensor size. What coelacanth is referring to is "bellows" correction due increasing the focal length for macro photography?
Click to expand...

A change in format does not effect the f-stop.
 
Finder said:
There is no light loss as the lens is held at the correct distance from the sensor--these are not extention tubes. The aperture does not change.
Click to expand...


FInder is correct. The extra 'tube' reuiqred on an OM lens is only replacing waht would have been the mirror box on an SLR. THere is no reason at all why the lens is physically letting in less light than it was on an OM.
 
Yep. What others said. I was talking about extensions just as reference pointing out what *might* be causing the "loss of stop" someone mentioned that re_visible read. My main point was format change won't affect the use aperture itself.

Just for the sake of argument, if the extension (close up ring or adapter or whatever) is vey long, you DO have to compensate the exposure, but OM or any other adapters for m43 is still quite short so there shouldn't be any loss.
 
Last edited:
Hmmm... Since f stop is the ratio of aperture size to focal length and the change in format from 35mm to micro 4/3 "doubles" the focal length, this would change the f stop shown on the lens by one stop? The amount of light has not changed, just the variables use to calculate f stop has changed?

Not trying to pick a fight... just trying to improve my knowledge.

buzz
 
The formal "focal length" of the lens does not change. Only the sampled area of the available image plane is reduced, giving an "apparent" increase in focal length. There is no change in the minimum stop except as there might be interferences around the edges by the adapter structure.
 
Verifiability?????

Verifiability?????

buzzkill58 said:
Hmmm... Since f stop is the ratio of aperture size to focal length and the change in format from 35mm to micro 4/3 "doubles" the focal length, this would change the f stop shown on the lens by one stop? The amount of light has not changed, just the variables use to calculate f stop has changed?

Not trying to pick a fight... just trying to improve my knowledge.

buzz
Click to expand...

Seems like the verdict on losing an f stop due to the crop factor is mixed with some saying the 2X crop factor loses one stop aperture, and others saying "not".

It would seem simple enough to verify the reality of either one of these points of view by using EXIF data, and comparing to an accurate hand held meter. Use matrix metering against the hand held.

Would this not resolve the discussion, number one. And number two, is one stop really an issue?

Another challenge might be for one to use an OM Zuiko legacy lens (a 50 equivalent on 4/3 is 100mm), and check the metering on an OM film body, vs checking the lens on a 4/3 Olympus body, verifying metered shutter speeds. Have to think about that one to get Apples/Apples.

Not enough of an issue for me to run the test.
 
Last edited:
@DrLeoB - Thanks for you reply.
@kuzano - For me it is an interesting discussion from a theory view point. I do like the idea of M-mount lens on the micro 4/3rds cameras.
 
I find it interesting as well. ....

I find it interesting as well. ....

buzzkill58 said:
@DrLeoB - Thanks for you reply.
@kuzano - For me it is an interesting discussion from a theory view point. I do like the idea of M-mount lens on the micro 4/3rds cameras.
Click to expand...

And like all discussions of the world of physics, I find, as I'm sure you do, the distinctions between theory and real practice often surprising.

I may test this further as I described, after life allows me to engage in this.

I find the comments widely varied on this, but in real practice, whenever I use my OM Zuiko 50mm 1.4 lens on my 4/3 camera, I find two interesting realities.

My bokeh, or OOF areas are as evident as they are when I use the lens on my OM-1 body and film. DOF seems to be, again in reality, not much changed. Furthermore, a cursory look at exposures seems to yield very similar exposure settings on film, as well as the digital. I also find this to be true on other legacy lenses. I do not have M lenses, however.

A disconcerting aspect of the desire to use an existing stable of lenses is that the dedicated lenses (prime and zoom) built by Olympus and Panasonic for the 4/3 and m4/3 systems, are rather remarkable in their own right and cross the divide quite nicely. I hear many "real life" comments that using the legacy lenses is interesting, but many don't see much advantage over the lenses built for the system. It's hard to sort this out from anecdotal comments read on these sites.

I am going to spend the $599 for the Oly E-PL1, after reading a number of quite good reviews. It has the latest sensor for 4/3 and the latest Image Processing engine, plus flash and Image Stabilization. It has the port for the EVF, which I won't buy up front. It seems only to be raising discussions about control wheels vs menu driven controls.

However, it's state of the art, takes all the same adaptors as do all micro 4/3 cameras, and that price point is just slightly above the high end but still tiny sensored Point and Shoot cameras.

It's a justifiable way to test the water on determining reality vs. theory for the adapted lens situation.
 
Last edited:
kuzano said:
And like all discussions of the world of physics, I find, as I'm sure you do, the distinctions between theory and real practice often surprising.
Click to expand...
It is very interesting... practical application of complex theories can be surprisingly straight forward and simple.


kuzano said:
It's a justifiable way to test the water on determining reality vs. theory for the adapted lens situation.
Click to expand...
Sounds like an interesting project!
 
You must log in or register to reply here.
Back
Top Bottom