Mamiya 645 AFD and FD canon 85 1.2
/forum/topic/771979/0

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Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

Ok, for those of you who ever wonder what would be if we take really fast lens and use it on the larger sensor area

At the moment, this convertion is in the middle stage and the far focus is about 3 meters - need to trim Mamiya mirror and position the lens in its mount a bit deeper inside the mirror box, in order to achieve infinity focus and need to make a new aperture control lever or ring. I just want to know, would this lens cover the larger sensor area and what drawing it will show.

The result really amazed me in terms of double character of the lens. It could be more pronounced then the Oly OM 55 1.2 and it could defocus the background like 200mm 1.8

So here are just test snaps handheld so it is possible that there are some mis-focused and out of focus objects (I have already bought microprism screen and will install it when the mirror will be trimmed)

Mamiya 645 AFD + Canon FD85mm f1.2

wideopen Velvia 50

This image is copyrighted by the owner

bigger size

wideopen
Kodak ektar 100 (120)

This image is copyrighted by the owner

stopped down arround f4-5.6

This image is copyrighted by the owner

check the same scene with fast normal primes here

samples from the 50mm group

So here is 55-58 group

double click to enlarge

http://www.fredmiranda.com/forum/topic/763806

joeisayo
Registered: Apr 15, 2004
Total Posts: 554
Country: United States

The images look very similar to my 85L II with an extension tube at the closest focusing range.

Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

Do not forget the field of view is like 50mm lens on 35 format, but the defocus if you have 50mm f0.7-0.8

pentaxshooter
Registered: Jun 23, 2007
Total Posts: 225
Country: United States

This is beyond awesome. I would have never expected that to cover the 6x4.5 frame. Tooo awesome.

wayne seltzer
Registered: Dec 22, 2007
Total Posts: 3201
Country: United States

Great job Dimtry!
Sounds like a lot of work but well worth it.
I really like the dandalion shot. Incredible.

ulrikft
Registered: Apr 17, 2008
Total Posts: 2316
Country: Norway

Very cool indeed!

sirimiri
Registered: Dec 10, 2007
Total Posts: 2561
Country: United States

Impressive amount of work. I bet it would make engineers who worked on both pieces of equipment happy, to know they someone is tinkering with their work, adapting to new and heretofore unthought of uses. "Homebrew" as they say.

As Pentaxshooter said, I'm impressed there's enough image circle!

ovredal73
Registered: Jun 21, 2005
Total Posts: 2478
Country: Norway

You never stop amazing me Dmitry - that is a feat for the books. Wow.

GoGoGoGo
Registered: Apr 18, 2006
Total Posts: 487
Country: United States

Wonderful look in these images, beautiful really beautiful.

Ed Sawyer
Registered: May 08, 2007
Total Posts: 1992
Country: United States

it is impressive it covers the image circle, which must be what, about 75mm?

nice work!

-Ed

fourfa
Registered: Oct 24, 2005
Total Posts: 2281
Country: N/A

I always suspected from the total lack of falloff at f1.2 (I'm ALWAYS adding vignetting with my EFII lens) that it has a much-larger-than-35mm image circle. Very interesting!

RyanFlynn
Registered: Dec 15, 2005
Total Posts: 2250
Country: United States

freaking awesome. ~50mm ~f/0.7? yes, please!

deepbluejh
Registered: Feb 20, 2005
Total Posts: 5901
Country: United States

I'm curious as to how much frame coverage you're getting.

Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

There is one trick - it is possible to use this combo if you remove the last lens element - which is the element of floating design and it is very useful in 35mm format. In this case you have 100% coverage without any sign of the vignetting wide open.

here is the light box for slide viewing

Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

So finally finished - have shaved the mirror about 7mm - really hard task, the mirror is thick and have aluminium base plate.
will try to show more samples from this combo, but after all these 10 fast 50-58 f1.2 that i have tried - this one is out of this world - it is 2 (or more) times extraordinary then Oly 55 1.2

Check this out - it is absolutely crazy - under direct sunlight without hood

wideopen
Kodak ektar 100 (120 film)

This image is copyrighted by the owner

Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

Here is something between f1.4-f1.8

Kodak E100G

Dim.ka_
Registered: Apr 30, 2008
Total Posts: 388
Country: Latvia

wideopen

kodak e100g

Graham Mitchell
Registered: Jul 14, 2005
Total Posts: 3699
Country: United Kingdom

Wow, very interesting indeed. Makes me want to try this with my digital back on the Mamiya! Please let me know if you ever bring this kit to Tallinn. Would be great to see it in person and meet such a passionate gear head

ovredal73
Registered: Jun 21, 2005
Total Posts: 2478
Country: Norway

Wow, you really need a specific point for sharpness reference or else the whole image might appear soft at these extraordinarily wide apertures. Last couple of shots almost feels like a lensbaby. This stuff is never-seen-before material - very cool, Dmitry.

Ed Sawyer
Registered: May 08, 2007
Total Posts: 1992
Country: United States

Wild stuff! It looks like the front-bokeh (foreground) has strong biotar-type characteristics, very swirly, while the rear-bokeh is a lot like OM 55/1.2 with a heavy dose of cat-eye type stuff showing too. Very cool!

so, do you have to remove the rear floating element to get full coverage of the image circle? Or can you get full image circle coverage w/o removing that?

-Ed

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