DIY "mini35" using mediumformat lens

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Ted Ramasola

Ted Ramasola

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Hey guys i'm about to test tomorrow my DIY adapter based on rotating GG, but I'm attaching medium format lenses from Mamiya 645. it casts a bigger image on the ground glass compared with 35mm. I'll post results when I'm done tom. (will someone help me how? the posting instructions are "complicated" for poor ol'me).

Wish me luck.
 
Take the prism finder off and point the DVX camera vertically at the ground glass on your Mamiya.
You'll need some level of diopter lens for the video camera, but that's for you to figure out.
 
I'm testing it now. Actually I tested on an RB67. -much bigger than 645. If the concept works 'll use the rb67 GG on a smaller housing using the 645 lens.
 
The DVX will pick up the grain, dust and scratches on a static GG. I the rotating "GG" is much better. I have to add an extension to the lens "mount", made from the lens cap, because the rb645 lenses needs a farther focusing distance to the "GG" than a 35mm lens.
 
teddybear said:
The DVX will pick up the grain, dust and scratches on a static GG. I the rotating "GG" is much better. I have to add an extension to the lens "mount", made from the lens cap, because the rb645 lenses needs a farther focusing distance to the "GG" than a 35mm lens.
Click to expand...

When I did mine, I mounted to the sunshade, rather than the lens itself. Just made a plate to attach the two cameras. (I used a 6x6 SLR and focused on the viewfinder.)

And, yeah, gotta clean EVERYthing. :)

Dan
 
can u guys post some pix, clips anything????????????????????????????
is this based on the micro35 design ? or that DOF machine tutorial?
 
Unix said:
can u guys post some pix, clips anything????????????????????????????
is this based on the micro35 design ? or that DOF machine tutorial?
Click to expand...

If you do a search in Hardware for "Marla66" and go to the last page of the thread, you'll find a pic of what mine looked like, plus links to sample vids.

Or wait until next week or the one after...I think I'll be rebuilding it and geting some better video samples.

But all it is is a 6x6 SLR attached to the DVX. :)

Dan
 
I've done it guys. Finally finished the main construction part of the adapter. The extension cylinders for connecting to the dvx is still temporary until I can fix its distance to the adapter box. I've tested and calibrated the MAMIYA SEKOR 80mm lens for focusing up to infinity and DOF. -and I must say the results are worth the effort! The lens I tested has a max opening of 1.9 giving me a shallow DOF. Racking focus gave results I could never achieve with the built in lens. I'm cleaning up the wires today and continue to test.
I would like to share my test and design with you guys, please tell me how to post pics or footage.
 
teddybear said:
I would like to share my test and design with you guys, please tell me how to post pics or footage.
Click to expand...

You need to put pics & footage on another website, then link to it here in your message.

Using the "advanced" editor is the easiest way to do that...just click on the little pic of mountains and fill in the address for pictures you want to appear her, and click on the globe-with-chainlink to make a link to video (or another webpage, etc.)

Dan
 
ummm. sounds complex. I'l have to ask our multimedia dept. to find a host site. Thanks for the info Dan. In the mean time I'm testing it outdoors today.

If any of you guys wish to see the set up and samples before I can post in this forum my pics, email me at ramasola@globelines.com.ph
 
Hey teddybear --- RU on Bohol ?

wow -- I was there last November -- I wanted to put one of the Tarsiers monkeys in my backpack !
 
Sanchez,
Yes I'm a bohol based production house.
I sent u a private message.

overlandfilms
Thanks for your offer to post, I'll email to you still pics first then it's up to you if its worth it.
 
teddybear said:
Hey guys i'm about to test tomorrow my DIY adapter based on rotating GG, but I'm attaching medium format lenses from Mamiya 645. it casts a bigger image on the ground glass compared with 35mm. I'll post results when I'm done tom. (will someone help me how? the posting instructions are "complicated" for poor ol'me).

Wish me luck.
Click to expand...


Hi Teddybear, have you had success on your trials?
I am very curious to see some results since I am also considering some investments in this area.

How do you manage the fact that the image appears upside down? Fisicaly switch the monitor?
Do you know if it only appears upside down or if it is actualy recorded upside down on the tape?
 
It will be upside down on the tape, too. Not big deal...NLEs let you flip vertically with no great trouble.

note: the first adapter I made flipped vertically AND horizontally. THAT, you don't want...takes forEVER to render.

Dan
 
Alceujr

I have already emailed e at overlandfilms the pics of my adapter and waiting his response to post them so I can send him test result video to assess also.

If you wish to assess them also please email me at ramasola@globelines.com.ph
so I can send you my test video in DV format and pics of adapter with medium format lens attached since I don't have a host site for posting pics.

Yes, the pics are upside down in the adapter but turning the LCD around but not all the way will give you a right side up image.(pics provided)
The recorded image will have to be flipped in post. But this is a minor issue since most NLE's have this feature.

For all other forum readers who are interested, please feel free to email me for further correspondence. I can provide the design of the adapter also for you guys to further improve.
 
Here are pictures of the adapter for medium format lens and sample frame grabs.

80 mm lens on the adapter
adapter_w_dvx1.jpg


a grab
stairbalusters.jpg
 
i have a question for teddybear or for anyone in that matter: What would be the advantage of using a medium format adapter versus a 35mm adapter?
 
kyledroid said:
i have a question for teddybear or for anyone in that matter: What would be the advantage of using a medium format adapter versus a 35mm adapter?
Click to expand...

In my experiments, the medium format lens casts a bigger image onto the rotating ground glass as compared with a 35mm lens. I think this is better for the dvx to record from as it doesn't have to zoom in to a small area thus getting a clearer image.

I also think you have more illumination in your image from the much larger "hole" of the medium format giving you more flexibility.
 
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