BJ35 Static Adapter w/ self-ground 5 Micron Nikon PCX from Chris Adler on Vimeo.
For more information click here.
The 35mm adapter blog is a resource to aid you in your understanding of 35mm adapters and help source products and parts.
I've finally got around to cleaning up the look of this site. I plan on adjusting a few things over the next few days. Hope everyone enjoys the nice clean look of the site.
*Update This is not a 35mm adapter in terms of the adapters discussed on this site. It actually allows attachment of lens extensions to produce macro footage (which has a shallow depth of field).
The following footage I came accross comes from the Showtime 35mm adapter out of Taiwan. Granted all the footage are macro. Unfortunantly the site is not in English, so i am unable to translate. (If anyone want to translate this site it would be greatly appreciated as this is some of the better adapter footage I have seen.)
dragonfly TAIWAN from frankwu on Vimeo.
Megalaima oorti TAIWAN from frankwu on Vimeo.
Labels: Showtime 35mm adapter
Today I will provide insight on grinding your own glass for your adapter. There are a few options to consider when grinding your own glass such as glass type and desired grain (determined by grit).
Why grind your own?
You could purchase a Canon EE-A EE-S focusing screen and achieve great results, however these screens are extremely fragile and can get costly to replace. DIY ground glass can a budget friendly alternative and can be washed with soap and water and not be harmed. One advantage the aforementioned focusing screens have is a built in condenser (Fresnel lens) that reduces vignetting and light loss, however there are ways to compensate for this with your own ground glass which I will get into.
What glass should you use?
A lot of people use cheap microscope slides which work fine, however you will have hotspotting and vignetting if a separate condensor lens is not installed. An alternative that does not require a separate lens is to grind the plano (flat) side of a plano-convex lens. Justin Snodgrass(snodart.com) suggests using the plano-convex lens from a Nikon F3 series focusing screen***. This is a good option for size and quality.
***Update Nikon F4 and F5 focusing screens also utilize the same quality PCX glass
What grit do you use?
Aluminum Oxide grit works well and comes in different flavors (sizes in microns). The size grit you use comes down to adapter type and personal preference. For static adapters I would suggest a grit size of 5 microns. For vibrating or spinning adapters it is pretty open to preference. Aluminum Oxide grit can be purchase from GotGrit.com.
How do you grind it?
Grinding is a pretty simple task.
I posted a while back that there was a new maker of GG holders. Seems like he makes his own ground glass and full adapter solution as well. Introducing the GT35pro.
Ground Glass (focusing screen) Holder
The kit comes in a set. The gg holder (including the metal legs, the vibrating motor and 2 ground glass of your choice. All the parts have been tested over and over again to make sure that the vmotor vibrates the focusing screen correctly.
Ground Glass (focusing Screen)
- 5 micron grind USD$20 up to 40mm x 30mm size
- 9 micron grind USD$15 up to 40mm x 30mm size
- 20 micron grind USD$12 up to 40mm x 30mm size
These glass can be touched washed and cleaned, unlike those canon EE-A or EE-S screens that spoils after you touch it.
GT35pro Vibrating 35mm adapter
The Price of the adapter without achromat and lens is $260.
Footage from the GT35pro
35mm DOF DIY adapter motor and pcx lens test from Greg Tay on Vimeo.
Just recently can across a few 35mm adapters on ebay that are going for great prices. See below.
Labels: great deals
I'm back from vacation bearing a gift :). Here is the final in the four part tutorial of building a vibrating 35mm adapter.
35mm Adapter Tutorial Walkthrough 4 from Martin Frericks on Vimeo.
Just a quick note. I will be on vacation from 8.4 - 8.10 so there will not be any updates for a week.
I have a quick correction that I plan to follow up with a new post on condensors, specifically using a PCX lens as a condenser. I mentioned below that the PCX condenser spreads light...this is not true. the PCX condenser actually converges light on it's own, however, it can be used to counter the diverging light coming from a 35mm lens and produce and even consistant light stream...I will have a new post on this topic soon.
Actually I should say “Spreading Some Light”. One of the least talked about elements of an adapter is a condenser. A condenser is most commonly a plano-convex lens (PCX) and basically spreads light. You would want to use one in you adapter to help eliminate the center hotspot and reduce vignetting.
The condenser would typically go between your 35mm lens and your ground glass (focusing screen). In essence it will take the incoming light from the 35mm lens and widen it to a larger area on you ground glass resulting in more light and less vignette.
Is a condenser necessary
Most would say a condenser is an optional element to an adapter, but I personally feel the benefits from a good condenser are too great to ignore. Overall image quality is much improved and PCX lenses are inexpensive.
When to use a condenser
I would recommend a condenser if your footage suffers from vignetting forcing you to zoom in extra on your ground glass. Also, if you are using custom made ground glass, wax screens, or other (example: I am utilizing a focusing screen found in the LCD of an old cell phone) I would say you will most likely want to use a condenser.
Canon EE-A/EE-S screens got you covered
If you are using a Canon EE-A/EE-S focusing screen then you already have a condenser. The EE screens have a fresnal lens attached which is actually a condenser.
Footage from a 35mm adapter utilizing a condenser
<>35mm adapter demo reel from AlexeiP on <>Vimeo.
Sourcing Plano-Convex lenses
Just make sure you get the right size for your adapter.