Marty:

From my experience, you cannot expect an image size any larger than a 35mm image. You start running into vignetting issues, and in fact, your effective image size might be slightly smaller.

As far as increasing depth of field, I think you do hit on something that happens a lot. We tend to shoot adapters wide open, because of light issues. Also, in closing down the lense, vignetting starts creeping in on a lot of lenses. I think shooting at a f4 or 5.6 will give you a better chance of getting the full face/head in the field of focus. I got a hold of Nikon F 1.4 that does not have the vignetting issues for some reason going into the higher F stops, and it gives you more control of that zone of focus.

Thanks everyone. Just to be clear I do not desire a larger ground glass area. I just recall reading that so many of the 35mm adapter have a softer more shallow DOF than even 35mm camea because the area that they project onto is larger than a 35mm sensor would be. Oh well.

But, I need to get my hands on one of these soon. Thinking about all of this I cannot imagine how far I need to zoom to get a 35mm size little area directly in from of my lens to fill the frame. In doing this the aperture of the camera decrease significantly I would imagine. It doesn't seem plausible....yet it is.

On the bright side, if you can use the iris inside the camera to set your exposure properly and you have enough light then you should be able to use just about any fstop you desire with the external lens. In other word, iris on it would simply be used for setting DOF and not necesarrily for exposure. right?

Assuming you have adequate light in your scene, you are correct.

Thanks for sharing Steve, very nice & sweet work :D.

:)


Thanks for all the input everyone. There's never a dull moment in my threads :)

Marty,

At the heart of the design in most 35mm adapters are 35mm SLR-sized ground glasses. Since the targeted market is for most who cannot afford high end adapters and for those who already owns 35mm SLR lenses, the ground glasses are made to work in that way, i.e. the image area is 36mm x 24mm.

Actual usable image area is debatable since it depends on which adapter, on which camera and on which lenses. These are the vignetting or edge to edge sharpness issues that are well documented in these forums. DOF characteristics for the SLR lenses are still the same regardless of how much image area you use.

Compare that to 35mm motion picture film. The Super35 format has an image area of 25mm x 19mm. Usable area here depends on which aspect ratio you shoot at. DOF characteristics for the format remains the same throughout all aspect ratios.

So as far as your concerns for adapters being shallower than 35mm motion picture film....I highly doubt it. My only concern with these adapters is the use of cine lenses on a 36x24 ground glass.

But that's for another topic another day. Now back to the topic!

Great images with the letus! May I ask which Letus are you using with the A1? The LetusA or FE? Best shots for me were at 0:35 and 1:05!!!! There is a story to those shots! I definitely agree that your kids have the best photographic childhood anyone can get!

Not only iris, but shutter speed and gain, too !

Can we look forward to topic next Friday ? :)

You said the G word!

I understand that the cropping of the image doesn't affect the DOF. I was talking about if the image size projected from the "front" lens was different....caused by distance perhaps. Say light enters through the lens and projects onto a 35mm print. Then say that same lens is mounted on a 50mm print camera and the distance between the lens and the sureface area of the film is increased. At the same settings wouldn't the depth of field be far shallower on the 50mm print?

I am assuming this based on working with a photographer who does amazing portrait work and he used large format film to accomplish great DOF effects. He described to me that this is a byproduct of the film size and not just the lens.

If that is true, then a 35mm adapter that projected the image onto a larger area of the ground glass (potentially furhter away?) should affect the DOF also.

Zooming or not zooming into the ground glass by the camera would not affect this...that would essentially be like cropping the image.

Either way it is a moot point! Just some BS theory!

OOPS... and I forgot to mention NDs too...

Would not affect depth of field, but the farther way you get a 35mm from lens from the GG, the less ability you will have to focus to infinity. In other words, one of issues with any adapter is it set up with the right distance to the GG so the lens has the proper focus range. Too close to the GG, and the lens focuses past infinity, to far away, and you don't get focus at infinity, but you start getting macro focus capability.

Now there are those who are trying larger format, cameras that throw a larger image. I've gotta Kowa Six Ive threatened to do that with, but I think depth of field will be even shalower in those cases, as a normal lens is 85mm, wide is 55. One of these days I'll try the 55 in a makeshift way on my DIY adapter, but I am not expecting much.

Chris I think that you are getting the idea of how it works.

There are two kinds of 35mm that are being talked about as one.

First there is the 35mm Film camera and then there is the 35mm still camera.

The still is about 2 and change times larger than the film. Therefore the 35mm adaptor that uses 35mm still lenses have a shallower DOF because the film plane is twice as big as a 35mm film. That is why a film camera's regular lens is about 20mm and an still camera is about 50mm.

That is what someone meant when they said that the image area of an adaptor is bigger than a 35mm. Meaning that it is larger than a 35mm film plane.

Another thing, by analyzing the still picture you can tell that the focus is behind the eyes.

Most lenses are sharper when closed 2 f stops from fully open. This specially true on under $10,000 video cameras. 35mm still lenses are no exception. You can't expect a $400 lens to be as sharp at full open as it would be by stopping it down a couple of stops.

To achieve a sharper image on a 50mm f1.4 you have to stop down to f2.8 while on a 28mm f2.8 you would have to stop down to f5,6.

Someone did a comparison of some of the 35mm adaptor (sorry I can't remember his name. An English fellow I think) and he came to the conclusion that they all looked better with the lens stopped down from fully open.

Another thing to consider when it comes to digital camera is that it introduces electronic sharpness on the blacks to make the image look sharper.

A more contrasty lighting help the perception of sharpness. In the case of Steven's daughter a harsher lighting wouldn’t have help sharpness because the young girls face is silky smooth. Instead an old wrinkled person with harsher/contrasty lighting would have the image appear sharper.

Sorry about the long rant but I am still at Vegas Airport. I have another 5 hrs before I get in the plane for a 6.5 hour red eye flight ;D

Douglas,
Thanks for the info. I knew somewhere, someone had mentioned something about 35mm lenses being something else or something.....

:)

Seriously I think you hit it. It was that a 35mm still camera is larger than the area of a 35mm film camera. That has to be what I was thinking of......I think.

So potentially some of the perception of sharpness can be caused by the Nikon lenses that Stephen is using. IF he were to stop down it could do 3 things. Expand the "in focus" area of the image, potentially having all of his subject in focus and increase perceived sharpness too.

I do know that my 16x manual lens for the H1 I can see a serious kick in the sharpness pants when I can film at f5.6 vs. f1.6. So I guess optics are optics and I should expect to live by these same rules for 35mm glass too.

Thanks.

Douglas, many thanks for your insight. This has been an education :)

From what I understand, what Doug was saying is that 35mm for a film in production, the width of the image is measured inside of a strip of 35mm film if held vertically, whereas, if we were shooting 35mm film in a still camera, the height of the image is that same measurement, and width is about 2.5 times that height. Do I have that right ?

Not ever having seen a 35 mm film camera up close, this makes sense to me.

That is exactly right, a 35 still shoots +- 36 mm wide while motion film is +- 24 mm wide.

2.35:1 aspect ratio
 

Steven -- I understand you apply a matte in post to achieve this aspect ratio, but when you shoot, do you have some sort of markers that remind you where your frame is? How do you frame for this aspect ratio? Put tape marks on your LCD??

Thanks.

the XHA1 has a 2.35:1 guide bars

Well I'll be danged, so it does. Thanks, Marlon. Had glanced through the book, didn't find it, but there it is as a menu item...

I was a bit late downloading this.. Brilliant as always Steven. The music works really well too.

Wow.... really, Wow.

Steven, you mentioned what lenses you used. Is it fair to assume that the order you listed them is the same order you shot with for this piece?

Not really DJ. You can judge the extreme closeups with the very narrow depth of field were shot with the 100mm, the long shots were shot with the 28mm and the medium and medium/close shots were with the 50mm (for the most part, there maybe some variations, I just don't remember)

Hi Steven,
Just curious what kind of support do you use for the letus. If there is no support wouldn;t it damage the thread on your A1?

thanks ys

I don't use any support because the lenses I use are small and relatively light. I think the whole thing, including the lens is about 1.25lbs. With a bigger lens, I would definitely use support.

Hey Steve, outstanding work. I've enjoyed watching all of your films.

I've also shot with the Letus Flip enhanced on my FX1. The biggest thing I notice in your footage is the same thing I saw in mine - the texture of the ground glass always seems to be there. It isn't terrible and is almost a stylistic thing but I sold my letus and bought a Brevis. I think you should try and check out a Brevis if you get the chance. The Brevis is MUCH BETTER. The ground glass in the Brevis completely disappears, no grain, no texture of the ground glass. And it loses a whole lot less light. And it's constructed much better (not plastic). And it runs off a rechargeable battery. I could keep adding Ands.

...and it costs twice as much and it need to be flipped in post.

Seriously the all have their plus and minus.

Agree with Douglas here.. I am, frankly surprised how now nice the Letus does for the price. In my case, I am not using flip version. My understanding though, is that Cinevate is working on a flip version....

I had wanted to go with the Brevis, just because it looked more, hmmm, classy, but buying the Letus handyman special at $375 with the combo Nikon/Canon mount was just too tempting, and my first months fun with it made it worth the risk....I am shooting it with the HV20 and FX1, and it is working well with both.... With HV20 flip the whole camera with a device I made that is mountable on a tripod, and that works out flip issues, mostly....

By the way I don't know if you heard that the M2 is coming out with a flip.

I saw it at NAB in the Panasonic booth and it looked really good.

I've owned both. Paying more for Brevis is the difference between home-made and professional. Brevis is much better in every respect but most importantly Brevis produces a better image. The Flip enhanced is brutal with light loss (and $700 vs. $1000 isn't a huge difference in price). With Letus I had to shoot everything wide open and I was still stretching my lighting package. Flipping the image in post is super easy and options to flip during capture are more common. Flipping is just not a meaningful feature to me. Plus you can always shoot with the camera upside down and then your image will correct if it's such a big deal to you. Losing a whole stop more of light is a huge price to pay for such a simple convience. But the texture of the ground glass on the image is the deal breaker for me. With Brevis there is no texture and hardly any light loss - less than a stop. The letus flip enhanced loses at least two stops and I'd rate it 2.5 stops of light. Losing less light makes Brevis so much easier to shoot with.
Everything is a trade off, but there is no question that Brevis produces a better image.

And I bought my Brevis used. I got the Brevis, the Red Rock Macro, the Cinevate rails, & 2 lenses for $800.

Hi Nathan,
Just wondering will we be able to handhold the camera plus brevis setup during filming? say i am using a small 50mm lens? if i do not use rail support will i risk damaging the camera's thread?

thanks
ys

No you won't damage the threads. You don't need rails with the Brevis. It's very run and gun friendly especially with small lenses like a 50mm.

wow that means with the brevis HD bundle i am ready to start filming?

One last question which may sound silly... that is can i still use the zoom in my camera when i have such adapters attached? Or i must follow some rules like it should always be set to the widest?

Thanks
yslee

It does sound as though you need some expereince using these adapters. Here's a short explanation and this goes for all of them, M2, Brevis, Letus, SG Pro, Mini-35. The adapter is basically a film frame size piece of ground glass. The ground glass spins (sg pro, M2) or vibrates (Brevis, Letus). All of these units attach to the front of your camera (M2 and SG Pro require rails). You use the zoom on your cameras lens to fill you frame with the ground glass focusing your cameras lens on the grain of the glass. Then you won't change your focus or the zoom of your camera. It stays locked in. You attach a lens on the front of the adapter and you use that for zoomin(if you have a 35mm zoom lens) and focusing. You turn your adapter on and it vibrates the glass or spins the glass making the grain dissappear. The lens in your camera is now kind of out of the picture (pardon the pun). Because you are now recording the 35mm frame from your 35mm lens projected onto the ground glass you record it upside down. Some adapters have a flip option, or you can just flip it in post.

While the image is not as sharp as your camera's stock lens, as you can see from Steven's fine example video in this thread, the image is nothing like video anymore. If you want the film look - this is it.

Before I got the Letus, I used a self built. While I had a an achromat for the necessary close focus, I added a 5 inch extension tube which gave me a zoom range on the ground glass image. However, remember, that ground glass image will deteriorate as you zoom on it...so using as much of the ground glass as possible seem prudent to me.

Hi Nathan
Thanks a million, yes i have not used one before. but from your explaination i now know what i am heading for.
Thanks again
yslee

I would like to say that your young model is absolutely beautiful. i hope that she is making top dollar for allowing you to photograph her.

Don