Homemade 35mm Adapter

[Filip Kovcin]

here is a link to my page where you can see my latest prototype of agus35 - made of aluminium. it's anodised and almost finished.

take a look.

http://www.astercity.net/~tarasuma/agus35.htm

[Nicholi Brossia]

That looks really nice Filip. You've obviously spent some time with the fabrication. Do you plan to use actual glass? or will you be using the plastic cd? I'm hoping that, after all that work with the body, you'll be using some high quality, finely ground glass.
Also, can you explain how exactly that wedge works... I can't really figure it out from the pics.
Great job on the adapter.

[Filip Kovcin]

<<<-- Originally posted by Nicholi Brossia : . Do you plan to use actual glass? or will you be using the plastic cd? -->>>

...

yes, you are right, i'm looking for really fine glass, but this is relativelly difficult to find here in warsaw. i'm in contact with an optician who is thinking now how to make it. the main problem for him is the hole in "frosted/glass CD". so we will see. until then i will test what is possible with fake CD version.

...
<<<--Also, can you explain how exactly that wedge works... I can't really figure it out from the pics. -->>>

the wedge is really simple. i just made shallow " L- shape" on the both parts of adapter in the absolutelly centered position, (let's call it "negative" shape) and after that i made "positive" part from aluminium. this positive L-shape is conecting both cover and bottom part, so when is positioned properly everything is in rock solid position.

and because i made both - the cover and bottom parts of the adapter with "positive" and "negative" screws - allways is possible to make small mistakes when you want to close- tight the whole adapter.
you never know is THIS position ok or a fraction of milimeter further... with that wedge you just know where you are.

so, in my opinion this wedge will keep all adapter in properly centered position. and the lenses will then work ok.

thank you for your feedback.

[Brett Erskine]

Filip-
Very professional setup. Great job! I like the adjustable motor mount and swapable lens adapter rings.

Are you planning on adding a condenser lens?

Did your parts come with the flat black finish or did send them in to have it done?

Why did you decided to rotate the GG instead of moving it in a overall circular motion?


Brett Erskine

[Filip Kovcin]

<<<-- Originally posted by Brett Erskine : ... I like the adjustable motor mount and swapable lens adapter rings. -->>>

thank you for your opinions.

<<<-- Are you planning on adding a condenser lens? -->>>
yes, definitelly. there is lot of space inside the adapter for that. but i'm consulting that with "my" optician. i must say that i can't work each day on this, so it goes very slowly, but i'm satysfied, because i can see more and more progress on this.

<<<-- Did your parts come with the flat black finish or did send them in to have it done? -->>>

i sent them to the special workshop where they finished parts in black. it's called ANODISING, (this is my "best guess" translation") - i decided to use black color - it looks kind od professional, at least more professional then yellow or dark brown, which was also the option there.

<<<-- Why did you decided to rotate the GG instead of moving it in a overall circular motion? -->>>

i know that this is not the smallest possible solution etc, but i said to myself something like this: you must finish at least ONE prototype in this manner (rotating GG, CD motor etc.) this is my fourth prototype, and i was ALWAYS borrowing something from the previous model, so the only reminiscence of my previous work were the pictures, nothing physically existing. so i decided to make it AS IS. and then to go further. with probably smaller glass, with different system for revolving or moving it etc. BUT...

i thing i owe something to Agus and this forum and this is kind of hommage to all of you. and that's the reason i decided to build it like this.


filip

[Bob Hart]

Filip

Talk with your optician. Ask him if he can polish one surface of a 150mm diameter disk and dress the other side to be the groundglass finish. The disks are cut optical glass with ground finish. I am ordering 10x pieces from Ohara in Japan which will have the 15mm hole in centre.

If you want to contact Ohara direct, the email is as follows :-

Hiro@ohara-inc.co.jp

When you receive a reply, be careful not to delete it as it will look like junk mail. It has a code on front of the address when you receive it.

Following is an extract from his last email to me with costs information.

""""
Dear Mr. Hart;

OK, let's assume that the total weight of the package for 10 disks will be 5Kgs maximum. In this case the freight of the International Parcel from Japan to Australia is JPY8,200. So the additional cost per piece is Y820. Therefore our F.O.B. Japan Price of Y3,400 / pc turns into C & F Addressee Y4,220 / pc.

The total amount to be transferred to our bank account is Y4,220 X 10pcs= Y42,200.-

""""

Wedge (key) idea is very crafty. It eliminates my idea for using a lens tube right through the whole cover assembly. I am curious about the threaded mount for the PD150. The 58mm front filter mount
on the PD150 is plastic. If the Agus is to be mounted and dismounted from this, I would be inclined to use a 52mm mount and install a permanent 52mm to 58mm in the PD150 to avoid damage to that plastic thread. Alternatively I might stay with using the bayonet mount on the PD150. That is made of plastic but is wider. It has been strong enough so far to hold my Agus35. I made the matching mount of plastic to avoid damaging the plastic case on the PD150.

[Dino Reyes]

Filip that is so beautiful! excellent!

[Lyndon Golanowski]

is this the spindle pack everyone is using?

http://www.walmart.com/catalog/product.gsp?cat=3951&dept=3944&product_id=2326562&path=0%3A3944%3A3951%3A3955%3A4460

try and find an image of the pack your using so its easier on us stupid guys to build this thing..thanks

[Bob Hart]

TWO-LAYERED GROUNDGLASS.

For those who are following the fixed groundglass path, here is something which may be of use or worth developing to a higher level than I have time to do.

Whilst educating myself with microscope slides in the method of polishing glass before I turn myself loose on the real glass disks, I decided to see if I could replicate the partial polishing back of the plastic CD disks which seems to confer an improvement in the brightness and sharpness of the projected image.

I discovered after polishing back some of the frosted finish on glass slides to a semi-opaque condition, it would be of little use as a groundglass screen because of hot spot and some of the aerial image being apparent.

But with two such groundglasses mounted with polished-back frosted surfaces face-to-face, a more useful projection surface can be found with the finer texture remaining, therefore hopefully better resolution than with a single more opaque frosted surface of coarser texture.

The downside will likely be two internal reflective surfaces instead of one and anti-reflective coatings on the clear sides will likely be mandatory to avoid ringing or spill around pinpoint bright spots in the image analagous to halation with motion picture film.

[Bob Hart]

Furthur to above.

I have sent Chris some frames from my first workmanlike excursion for the non-inverting AGUS35 - PD150P combination. It was to record some performances of an R and B gig for shots to be extracted to include in a no-budget music video for the performers. The image filenames are "mtatk2f1.jpg", "mtatk2f2.jpg" and "mtstk2f4.jpg".

Lighting conditions were our autumn (northern hemispherers, = your fall) 4-00pm - 4-30pm, intermittant thin overcast, facing south (northern hemispherers = facing your north). The images were shot in electronic 16:9, squeezed, inverted and captioned in Ulead Photoplus4, but otherwise not altered.

The AGUS35 setup was rotating plastic CD made opaque in two processes, pressing with 600 grit, subsequent dressing with fine aluminium oxide then partial back-polish with a soft cloth. The disk has several deep scratches in it.

As a practical work tool, the AGUS35 has a long way to go yet. The non-inverted image is a serious distraction to good framing and if depth of field effects are being pursued, then motion film best practice of prior rehearsal and a focus puller should be followed.

[Chris Hurd]

Yahoo! I got to make post number 1,000 to the lengthiest, most intense thread we've ever had here at DV Info Net.

Bob's images are up! See http://www.dvinfo.net/media/hart.

[Filip Kovcin]

he, he...

and i'm just first in new "millenium" :))))

[Bob Hart]

Brainpick time if anyone can offer advice.

I'm attempting to invert an AGUS35 image in Premiere. The image was aquired on a PD150P in DVCAM in electronic 16:9. Whilst inverting I am letterboxing the image. I am also de-interlacing the image before applying effects in an attempt to reduce the jitters in the final product.

All efforts so far with two music videos have resulted in a severe loss of resolution by comparison with the image played straight off the camcorder into a TV set.

As well as a loss of resolution I am ending up with a severe stepladder effect on straight lines which run obliquely in the image, ie., guitar frets and strings. Te image appears to be segmented with vertical divisions which distort objects as they pass across these divisions.

Vertical objects such as poles will thicken and go thin again as the frame pans across them when small adjustments have been made in the framing.

Is this a product of letterboxing from electronic 16:9. Previous letterboxing has not introduced this problem but it was not AGUS35 footage and was shot with a anamorphic 16:9 lens.

Whilst this would hint that electronic 16:9 might introduce some faults but previous work I have done with electronic 16:9 has not introduced this problem.

Any clues anyone. Advice will be greatly appreciated.

[Agus Casse]

Are you deinterlacing it in Premiere or in AE ? what i do is to first deinternalce, then pre compose, and rotate de image, and then precompose again, so i can apply the filters that i want.

Also be sure to turn off the steadyshot function. That will make some images a staircase problems in some parts.

[Jim Gauthier]

For those experimenting and/or prototyping, you may want to try (if I hadn't missed this elsewhere in the related threads) making the focus screen slightly adjustable to tilt from the top and bottom to give it the tilt/shift adapter look.