Looking to purchase a Letus

[Jarrod Fegley]

I am in the market for a DOF adapter. The camcorder I would be using is a Panasonic HDC-TM700. This camera has a 46mm thread on the front. Could I get a Letus to work on this cam? I am guessing I could use a step down ring but would that create a vignetting issue?

[Bob Hart]

Your post hints that you may be chasing something which is pre-owned.

I would not expect that you would have problems using an adaptor ring. You may find on the Home or Letus Corporation - Manufacturer's Website websites that there is a direct mounting 46mm ring for your camera type for the Letus Extreme/Elite/Ultimate style of adaptors.

If you are buying off ebay or elsewhere and the Letus comes with an achromat suited to another camera type, you may need to be mindful of the chance that the special achromat lens for the Sony PMW-EX1 cameras may not suit your camcorder.

In practical terms, I found that the special achromat did not cause me any problems with the Sony Z1 I also used it with.

Provided your camera lens can cover the zoom range 40mm to 70mm, I think it will work fine.

If you intend to buy new, check the Letus "Mini" which might be more suited to your camera.

I strongly recommend you buy some sort of support rails system from the start. You will eventually do so anyway if you are serious about creative value adding to your images.

A 46mm diameter filter thread may fail if subjected to the bending loads the weight of the adaptor plus lenses will impose on the camera casework.

If you intend to mount your camcorder/Letus combination on a tripod, it will be almost impossible to do so with satisfaction without a rails system as the balance will be way out frontwards if you try it with your camera's own tripod mount and all the weight will be on that skinny screw, the camera casework and the forementioned 46mm filter thread.

The filter threads are often molded into the plastic of consumer/prosumer camera bodies and the threads are inclined to tear away in overloads or crossthread into ruination if operators are not careful.

Don't forget to use some bounceboards and creative lighting. Value adding does not come from an expensive camera or camera/35mm adaptor alone.

[Phil Murray]

Jarrod,

I'm sure no expert with Letus, but I just started working with a Letus Mini over the past 2-3 weeks and am learning to love it.

Looking on their website, it appears that none of their adapters has a 46mm mount, but the Letus Mini has 43mm mount available. Since you will have to zoom some anyway to get rid of the adapter's vignetting, the very small step more needed, if any, for a 46-to-43mm step-down ring shouldn't make a noticeable difference. Given the size of your camera, this adapter would seem to be a much more cost effective way to go as well as being a good size match.

Bob is definitely right in that rails are pretty much mandatory. You can play around with handheld shots, but since I assume that you are getting it for critical DOF adjustments then a tripod is necessary and the support across the camera, adapter, and lens is really important. (I use a set of Cavision 15" rails that I bought from B&H mounted on a Manfrotto 501 head.)

For what it's worth, I went with a Canon FD mount since there are some excellent lenses available which are very inexpensive. I have a 50mm f/1.4, 50mm f/1.8, 85mm f/1.8, and an 80-200 f/4 which is my favorite by far. (I do have a Nikon mount as well for an 80-200 f/2.8, but have never used it.) While I had quite a few Canon EOS lenses already, they were not fast lenses that would give me the shallow DOF that was the reason for the Letus in the first place. I don't think any of my lenses cost more than $100, though I was very patient in shopping the used lens market for good deals. You can pay more if you're in a hurry, but not necessarily a lot more.

I don't know how good is the viewfinder or LCD screen on your camera, but you may find yourself needing an external monitor. For critical focus, without a lot of sharp lines or a well-lit subject, it was very difficult for me even using my cameras focusing aids. I have a Manhattan LCD monitor with 1280x768 resolution, but a lot of folks seem happy with the much less expensive and more common 1024x600 resolution. (I would have gone that way, too, but got a great deal on mine.)

I really like the look that it gives and I hope to put it to even more use as I continue to learn how to use it. Shooting with a shallow DOF forces me to look at shots much more critically than before and that seems to have a positive effect on my work in many ways.

Phil

[Phil Murray]

Originally Posted by Bob Hart

Don't forget to use some bounceboards and creative lighting. Value adding does not come from an expensive camera or camera/35mm adaptor alone.

Bob,

Did you you add that last paragraph in relation to 35mm adapters, or just as an added comment? As I wrote in my post to Jarrod, I'm learning how to effectively use my Letus and would love to know your thoughts on specific applications of lighting with 35mm adapters.

Thanks for any insight you'd be willing to share with this rookie!

Phil

P.S. I agree that creative lighting, like sound, is so often overlooked. That's another area that I'm trying to imrpove in.

[Bob Hart]

My comment was an added afterthought.

Lighting for camera is a distinct craft in its own right, learned and developed by specialists over entire lifetimes.

Like paint artists, DPs and lighting specialists gain experience by testing and experimentation. Their interpretations even evolve into identifiable signature styles. Art wordstuff like "palette" will be read and heard. The lighting style of "CSI Miami" is a case in point.

Camerawork is an art form and let's face it, movies are fully intended to be larger than life as is so much other art.

DP Shane Hurlbut is apparently quite generous with craft information on his website which should be worth a look.

For myself, I don't have a clue beyond setting a key light, a fill light to soften the shadow the key light causes and back or kick lighting to make the hairs on the silhouette of the head stand out and separate the subject from an otherwise indistinguishable background.

All 35mm adaptors reduce the amount of light reaching the camera sensor. Where you might get away with shooting with no lights and no adaptor, you may have to add light with an adaptor on front. If you are forced to gain your camera up, with an adaptor on front, you will inevitably lose apparent sharpness as camera gain noise and textures conferred by the groundglass are additive in overworking the compression system of the camera's processor.

In low light, you also lose with non-cinema lenses in that the affordable stills lenses become less sharp with wide-open aperture settings. So with a f1.4 lens, your sharpness and contrast sweet spot may start at about f2. This is the logic of buying the fastest lenses you can for adaptors, not the razor-thin depth-of-field you can achieve with them wide-open. Try to light so that your front-end lenses are in the ballpark of f3.5.

At f4, you might risk some artifacts in some conditions with some lenses. It seems that artificial lighting is kinder to adaptors than outdoors.

A mattebox with flags and ND filters is preferable over camera internal ND filtering for managing exposure outdoors, also for keeping stray direct light from hitting the lens. It is desirable to maintain both your front-end lens in its sweet spot of about f3.5 to the limit of f5.6 and your camcorder iris in the zone f4 - f6.3 or thereabouts.

If your camera does not provide you with a shutter speed control option, outdoors you may be forced to use internal ND filtering to force an automatic shutter speed to be slower. 1/50th - 1/60th is best and is consistent with film camera shutter speeds. Hopefully the camera does not gain up instead of slowing the shutter speed.


So in short. A golden rule which should be broken when needs must :-

Front-end lens - as fast a lens as you can afford to buy.
Set iris - f2 - f3.5 unless you want razor thin DOF.
Shutter - 1/50th-1/60th sec.
Gain - 0db if possible. ( Some camcorders are apparently less than honest and are already gained-up at 0db. More = noise. ).
Use external ND filters or in-camera ND to maintain camera lens iris in the zone f4 - f6.3.
Avoid shooting against light without mattebox and flags. Direct light on front of lens causes unwanted flare. ( A sort-of DP's 1.01)
Avoid high bright midday overcast outdoors conditions for wide-shots if possible.
Sunrise - 0900am and 1600pm - sunset are nice times for outdoors imaging at geographical Latitude 32 degrees.


The lighting techniques you learn to use with an adaptor are equally valid in making vision direct-to-camera acceptable.

Relating to adaptors, although they may now embrace the new Canon 7D and 5D DLSR cameras, Philip Bloom and Tom Guilmette are worth reading on the subject of 35mm adaptors. They both have websites, www.philipbloom.co.uk and Tom's I cannot recall. Both have clips on YouTube and Vimeo.

There are DPs who participate here, Chris Barcellos and Charles Papert are two who spring to mind who have been generous with their information.

Ted Ramasola is also worth looking up. He built an adaptor for medium format lenses and used it successfully on a JVC GY-HD series camera. He is of a family which has worked stills cameras and portraiture for three generations.

These are people who make a living at this craft. Me, - I am more of a tourist and tinkerer.

[Kris Koster]

Relating to adaptors, although they may now embrace the new Canon 7D and 5D DLSR cameras, Philip Bloom and Tom Guilmette are worth reading on the subject of 35mm adaptors. They both have websites, Philip Bloom - DP, Director, Filmmaker and Tom's I cannot recall. Both have clips on YouTube and Vimeo.

Those guys may be embracing the DSLR technology, but if you're ever serious about getting your stuff broadcast, stick with the Camcorders + Letus for now. CMOS chips have lots of issues and the footage is getting rejected by the networks because of artefacts. aliasing, moire and rolling shutter issues.

Our independent company on a recent commission has been instructed that no more than 20% of footage will be acceptable for clips taken with DSLRs. The XH A1 + Letus? No problem.

DOF adapters aren't dead yet! DSLRs are fine if you're amateur or making corporate / non-broadcast material.