View Full Version : Will an adaptor make me happy?
July 2nd, 2008, 07:06 AM
I have been drooling over the footage I've seen coming out of the Letus and other adapters since I first got my eyes on them last autumn. Philip Bloom in particular has been an inspiration.
I own an EX1 and I guess a Letus extreme would probably be my choice. A few days ago I borrowed a friends HVX200 with a Letus Extreme, Nikon-mount and three Zeiss lenses (24, 50, 85).
My impressions during filming were that it was quite a big think to drag around. I also really missed being able to use the zoom when framing.
When I looked at the footage I was a bit disappointed. The image quality was so much lower than what I am used to with my EX1. Not very sharp (even though I filmed in 1080p) and the highlights blew out in a very unatural way. Now, I don't mean to bash any of you owning a HVX, but I am wondering how much of these arifacts can be blamed on the HVX and what can be blamed on the Letus/Zeiss?
Does anybody have any experience using both an EX1 and a HVX200 with the Letus? Also - what is you general impression of picture degradation when using an adapter versus shooting "naked"?
Also - like I mentioned - I missed the zoom. So, is using a zoom lens with an adapter any good? Is it too awquard? Are many of you using one?
I don't want to get an adapter and realise that I miss the crisp sharp images of the naked EX1. Please enlighten me!!
July 3rd, 2008, 12:57 AM
Only you can make yourself happy.
Your own self-training and skill set will determine what the EX1/Letus Extreme combination can do for you.
A quick test with a borrowed camera won't tell you the whole story of what you and the camera/adaptor are capable of. You need to take more time to learn to drive it and discover the rules and limitations.
As for using the zoom lens for framing? This is desirable when you must be agile and work quickly.
If you are able to take more time and care to compose your shots, then you might as well use the corresponding prime lenses.
Think of a groundglass device as another creative option for you choose from, part of the toolkit. You will not use it for all things.
Un-natural blown out highlights? My personal preference is to try as much as possible to keep over-exposures from the groundglass with added filters on front if the available range of iris control from the SLR lens is exceeded.
I too had far too short a time with the EX1. I did find but maybe am wrong, that I needed to try to keep the EX1 iris at about f4 for best relay sharpness.
I found I was over-exposing my shots initially when using the LCD and the resolution loss was very apparent. I did not have enough time to set the LCD brightness like I do the Z1 which I can work to quite well. "If in doubt, shoot under" seems still to apply here.
In agile work, matte-box filters might not be so convenient and you must fall back on the in-camera ND and iris controls.
Sony claim 1000 lines of more of horizontal resolution for the EX1. Most of today's groundglass adaptors should be able to give you 862 lines or better. There are previous comments on forums that the HVX200 imager has fewer pixels and that the image can be apparently softer compared to other brands.
The only valid judgement would have to come from controlled testing. The HVX-200 and a Redrock M2 have been used in a cinematically released feature movie "Sarah Landon And The Paranormal Hour", so it can't be all bad.
There will be an "apparent" loss of sharpness with groundglass adaptors. Some of this can be attributed to the optical performance of the adaptors but some can be as a result of the adaptors forcing a video camera to be "honest".
Artificial image sharpening becomes less pleasant to look at if the groundglass grain is captured. There are much fewer sharp areas in the actual relayed image due to operator choices of selective focus for the artificial sharpening process to sharpen. Operator incompetence in focusing becomes more apparent with 35mm lensing and groundglass relay. I come in for my fair share of that because I am short-sighted and accumstomed to "soft" images and have to conciously prompt myself to chase focus.
I found that the relay focus via the EX1 had to be maintained with much more care. Autofocus does not work as well as the Z1. Within reason, I can turn the autofocus loose on the Z1 momentarily when I think I may have bumped something off and be confident the camera has recovered the best groundglass image sharpness.
I found that the EX1 must be managed manually and for my own confidence, this meant shooting a resolution chart each time I checked.
Once the groundglass is running, it seems you can sneak in just a few more lines of resolution if you shoot a chart rather than rely on the sharpness of static grain. The Z1 autofocus finds this point, the EX1 does not.
July 4th, 2008, 03:40 PM
Only you can make yourself happy.
So true... I guess my title was a bit ironic. Thank you so much Bob for your great and lenghty answer! Anybody else that cares to comment on how zooms work with an adapter and what differences in image sharpness and overall quality of image (not considering the new DOP) the adapter produces?
July 4th, 2008, 04:04 PM
Using the adapter allows you to use prime lenses. You can't zoom in and out like a TV news cameraman. The camera's lens has to be set at a certain point, and it stays there. You change the focal length by using different primes. As you noted, it's more cumbersome than normal shooting. I would not want to use one for run-and-gun, hand held type things; that's not what they're for.
To my eye, the ground glass adapters add some softness. After all, you are shooting an image projected onto the ground glass. This softness isn't all bad, in fact looks pretty good on closeups. On wide shots stopped down too much, you might pick up the texture of the glass itself, and that's not good at all. So it takes more care to learn to use properly; if shallow depth of field is what you want, then it's a good tool.
As noted above the HVX is lower resolution and a little softer than the other 1/3" chip cameras. Since you're using the 1/2" chip EX, you're going to notice an even greater difference.
July 4th, 2008, 04:40 PM
An adapter will make your life more complicated. It also means more can go wrong. So question is it worth it. For avid users, the production value associated with the look and feel of 35mm depth of field is worth it. It definitely does not improve optical resolution.
You have to focus two times for every shot.
I shot a film recently with HVX200 and Letus FE (predecessor to the Letus EX). It was first time I worked with both pieces of equipment. About half way through film, the FE broke, (a wired connected to the vibrator had a bad connection). The vibrating screen would go off and on intermittently. We were in the field and I did not have access to soldering capabilities, so we had to go to my own older Letus35a. It wasn't near as nice in terms of optical capability, yet we had to try to finish film with it because of the contrast be straight camera shooting.
Next, with variable frame rates, you will want to do slow motion. Shooting at a slow motion (60p) results in ground glass imperfections showing up on screen more. Essentially, by shooting slow motion, you are also slowing the vibrating ground glass.
Just recently, I was doing a competition shoot theDVChallenge. I weighed going with the adapter as opposed to not using. Because of all of the complications, I simply decided to go without to simplify the shoot, and I think it worked out alright.
July 4th, 2008, 09:06 PM
This is where I might receive a slap over the ears.
I left some open interpretation in my wordstuff on the previous post relating to zoom lenses which should have confined my commment to putting a zoom lens on front of the adaptor.
In regard the lenses which go on front of the adaptor, my personal preference is prime lenses, - two reasons, wider available aperture and as a general rule, sharper for a similar build quality unless you buy a modern constant aperture zoom where the performance gap is much less apparent. A zoom will allow you to work faster, not necessary better.
The wider available aperture is not sought for a paper thin shallow depth-of-field, the typical signature of first time adaptor users ( a sort of "I do because I now can" syndrome. ). It is a sort of general rule of thumb that any lens performs better when the aperture is not at its widest.
So given a choice between using a f2.8 lens wide-open or a f1.4 lens at f2.8, I would favour the f1.4 at f2.8. There are exceptions to this rule. There are published accounts on Nikon forums that the 35mm f2 is sharper wide-open than the older 35mm f1.4 at f2.
As most lens kits for adaptors are babies on a budget, many lens purchases are of used older lenses. The older metal bodied manual lenses are often of superior build quality with tighter focus mechanisms but common sense says that you will not find modern optical innovation in old lenses.
With the Letus Extreme and some other alternative groundglass adaptors on "lens-in-camera" style camcorders, you can with care, use a little of the camcorder zoom movement for framing trims or dynamic effects but it is not something I would actively encourage as there is risk the camcorder relay focus will not accurately track the zoom movement. Magnify the groundglass = magnify the
grain and softness.
Chris has alluded to another fact, that a good groundglass adaptor does not replace the skillset of an accomplished operator, who can make the image out of the bottom of a glass bottle look good. It is just a tool, not a magic bullet.
I assisted an experienced DP who was operating an adaptor who like Chris suggests that life with an adaptor can become complicated.
He liked the look and the creative options but disliked adaptors because of nagging concern in back of mind over working around known limitations plus the added layers of potential error and mechanical failure which can go undetected. This can impede fast work and intuitiveness.