1. What is the purpose of the vibrating gg-holder?
The heart of a DOF adapter is a ground glass screen also named "gg" or "focusing screen". Like all ground glass, it has a very grainy structure (not to mention any dust or other contaminants on it). To lessen this the ground glass is oscillated rapidly to smear this graininess and therefore improve the (apparent) image quality. Disguising the grainy structure of the ground glass in this way, also produces the very subtle feeling, or impression, of moving film grain in a projected film emulsion, so the vibrating gg-holder itself contributes an additional element to the "film look" of the images it produces. (even if this is on a more subconscious level, and has no direct relationship to traditional film technology). For HDV a vibrating gg-holder is a must. For standard resolution a static gg-holder is okay because the grain is acceptable.
2. What is the best Canon focusing screen Ee-A or Ee-S?
The Ee-A has less light loss, but is harder to focus than the Ee-S.
The Ee-S is easier to focus because it has a special microlens pattern on it that makes the focusing much easier (Super Precision Focusing Screen) but its also a little bit darker than the Ee-A. Which one you choose depends on your needs and tastes. So there is no best focusing screen both are very good.
3. What is the difference between the VH-57 Ver. 1.1 and VH-57X Ver. 2.0?
There are two possibilities to build the dof adapter using the VH-57X or the cheaper VH-57 Ver. 1.1:
The VH-57X Ver. 2.0 has optional interchangeable gg-holder-plates for Nikon D, Canon Ee-A / Ee-S and for custom made focusing screens, its focal flange ready for Canon EOS tubes, space for a 49mm UV-Filter and has already its own vibrating motor included. Its easier for beginners to build their dof adapter because of the already fixed focal flange for Canon EOS tubes.
The VH-57 Ver. 1.1 is very compact, only for Canon Ee-S / Ee-A, needs a pancake motor i.e. 12-BMM Black Mamba Motor. The focal flange is adjusted by the user i.e. 41.6mm from the Canon EOS bayonet ring. If you have Canon FD lenses you should use the VH-57 Ver. 1.1 and adjust the focal flange for your Canon FD lenses.
4. What does the achromat actually do in the adapter configuration?
On camcorders without sufficient macro capability, a macro lens, preferably an achromatic doublet (to minimize chromatic aberration), is usually attached directly to the camcorder so that the camcorder can zoom in and focus on the focusing screen. Without the macro lens, certain camcorders would be unable to zoom in well enough to frame the entire focusing screen and still achieve sharp focus.
5. Help I have a woblling/shaking or blurry image with my dof adapter!
1. Check if your image stabilization is switched off! If its on then switch it off!
2. For best results don't use a shutter above 1/50.
3. Did you glued the VH-57X Ver. 2.0 to the bayonet ring of the Canon EOS tubes like mentioned in the HV20 tutorial?
If its loose the whole adapter will vibrate in the tubes and thats not right.
4. Try to lower the voltage with the 50 Ohm microrheostat until you barely can hear the motor. A big vibration is not always good. Tune it until the grain disappears and you will get a nice sharp picture. If the vibration is too big you will get a unsharp wobbling image.
5. Check if your focusing is fixed well into the gg-holder. If its loose it may begin to vibrate chaotically.
6. Always use manual focus on your camcorder! Autofocus will not work!
6. What parts do I need to build a dof adapter for my camcorder. I have a "...xyz..." camcorder.
There are only three designs for all camcorders. The main difference is only the achromat and some extra extension rings.
Big camcorders:
Panasonic HVX200, Panasonic DVX100, Canon GL1/GL2, Canon XM1/XM2 and other camcorders too...
For camcorders with a filter threading bigger than 43mm follow this design: http://www.jetsetmodels.info/pics/hvx200.jpg
Big camcorders with insufficient macro capability:
Sony Z1U, Sony FX1, Canon XH-A1, Canon XL2, JVC HD100, JVC HD200...
Especially for these camcorders you have to lenghten the whole dof adapter a little bit by adding some more extension rings
to be able to zoom in and focus on the ground glass element (focusing screen).
For camcorders with poor macro capability follow this design: http://www.jetsetmodels.info/pics/sony_z1u.jpg
Small camcorders with filter thread 43mm or smaller::
Canon HV20, Canon HV30, Canon HF10, Sony HC1, Panasonic NV series...
For camcorders with a filter threading 43mm or smaller follow this design: http://www.jetsetmodels.info/pics/hv20.jpg
7. I bought these tubes from ebay... Which gg-holder is compatible with my tubes?
Please checkout the macro extension tubes overview: http://www.jetsetmodels.info/pics/tubes_overview2.jpg
8. I have Nikon lenses why do you use Canon EOS extension tubes in your tutorials?
I use Canon EOS extension tubes because this is one of the largest lenses mounts. It makes it easy to adapt converter rings for other lenses like Nikon, Pentax, Leica, Olympus, M42, Contax-Yahica...
If you use Nikon extension tubes for your dof adapter you have to stick only with Nikon lenses and you're not able to use other lenses.
9. How does the Opteka HD² 10x macro lens achromat looks like?
I know the sellers in amazon and ebay do not write the diamter of the achromats in their description. Just ask them for the 55mm version of the achromat. The glass element of the achromat is always the same approx. 38mm. Only the thread diameter is different 52, 55 and 58mm.
For the DIY dof adapter you will need the 55mm version!
Click on the below image to get a bigger picture.
10. What are the best settings to get a really good image quality with a dof adapter?
1. Use good prime lenses from Canon or Nikon with apertures of f1.2, f1.4, f1.8 or max. f2.8. Everything above that like f4.0 or f5.6 will produce vignetting! Also don't use your lenses wide open or you will get a very soft image. Most lenses performs best and are very sharp if you close its aperture by 1 or 2 stops. Better checkout some SLR lens reviews for your lenses to know what its best setting are. Avoid zoom lenses they are not that sharp and most of them will produce vignetting when used with a dof adapter.
2. Use your camcorder always in manual mode! Don't close the aperture on your camcorder past f4.0 or you will loose sharpness. Most camcorders performs best at approx. f2.8 - f4.0.
3. If the image is too bright use the integrated ND filter (neutral density filters) from your camcorder or external ones. Avoid to compensate by closing the aperture of your camcorder or SLR lens!
4. For best results don't use a shutter speed above 1/50.
5. For focusing use an external 7" LCD screen. It's hard to focus with the small integrated LCD or viewfinder of most camcorders.
6. If you are serious about filmmaking go and learn lighting techniques. There are also special movie lighting techniques.
Checkout the internet. If the lighting is poor than you can't get good footage even if you own a very expensive dof adapter!
7. Only if you want to add a slow motion effect to your footage later in post production then shoot using a shutter speed of 1/250 or 1/500.
This will only work with static dof adapters or very fast spinning dof adapters! On vibrating dof adapters the image will start to shake. Turn your vibrating dof adapter off and use it static!
Informative links:
Here are some basic infos about dof adapters:
http://en.wikipedia.org/wiki/Depth_of_field_adapter
