EMJ & Moviestuff read in >>>>>>>

[John Jay]

you nuts and bolts engineering types should read all this thread


http://www.dvinfo.net/conf/showthread.p ... genumber=1

[MovieStuff]

:lol: I read the thread. Funny stuff, really. There seems to be this bizarre fascination with screwing up a perfectly good image by shooting off a rear screen, thereby adding the increased risk of vignetting and decreasing resolution as well as depth of field just to pretend that one is shooting 35mm, as if a good 35mm image exhibited those characteristics. This contraption had to be invented by a video guy, that's all I can fathom, but I could be wrong. No film guy would consider copying their film off of a rear screen so I can't imagine they would consider shooting their primary images off a rear screen, either. I've actually seen footage from this funky 35-DV thingy and, personally, I think it sucks. One of the people on the thread said there's no vignetting. Bull. The thing vignettes all over the place. It pretty much has to since it's a rear screen (ground glass). It looks nothing like film and merely succeeds in giving you a crappy image for a whole lot of $$$$. Amazing what people will buy these days.

Roger

[jessh]

I personally think that the principle could be used in some cool ways, such as being able to create a low res image with really shallow depth of field, even smaller than 35mm if you wanted. Might give a cool asthetic for some uses. I would be willing to pay a good $20 for something like this.

~Jess

[john jay]

Roger

Thanks for your take. I am a little confused by your amusement though.

I agree that the Pro35 adapter from P + S Technik is very expensive but shows none of the vignetting or loss of resolution that you speak of. Heres a typical shot to refresh your memory from those you may have seen, more can be found on P + S website



returning to the thread I directed you to, it would appear that such a device could be made for a whole lot cheaper. The current state of play on a 5$ mock up (ref CR) at half size looks like this



obviously there is more work to do to bring it up to the P+S standards, but I would have thought that such a low cost device would be desireable to both S8 and DV users

Further the reason I asked for your take is because of your work on the WorkPrinter which might have similarities to some of the technical problems involved

Regards

[MovieStuff]

I agree that the Pro35 adapter from P + S Technik is very expensive but shows none of the vignetting or loss of resolution that you speak of.

Hi, John!

Actually, there is quite a bit of resolution loss. To really appreciate the difference you have to see a picture made without the Pro35 as well as one made with the Pro35 in place. Any time you collect an image on a screen, particularly any type of rear screen, there is a fair degree of resolution loss. It is impossible to avoid. That does not mean that it can't still look nice but, considering that one is recording to resolution starved miniDV to begin with, lowering resolution just to get reduced depth of field (which is all you really get with this device) seems like going about it the hard way.

Regarding vignetting, every shot produced by the unit on the project I worked on had obvious vignetting. However, there seemed to be a difference depending on whether a letter boxed effect was being used. Unfortunately, I was not the operator for the unit nor had any direct contact with it. All I saw were the end results that my client was producing and the vignetting was there and, as I say, unnecessary for what they were trying to achieve.

Further the reason I asked for your take is because of your work on the WorkPrinter which might have similarities to some of the technical problems involved

Not really any similarites as the WorkPrinter doesn't use a rear screen but, rather, a condenser lens to carry the image.

In my opinion, the best thing that smaller formats have going for them is increased depth of field. Pros on 35mm film shoots have to kill themselves to even begin to get the type of depth of field we take for granted in super 8 or video, which can be minimized very easily to achieve about the same look, should anyone want it. But when you look at really big budget 35mm productions, they have plenty of depth of field when they want it and shallow depth of field is often reserved for isolation with normal to longer lenses, anyway. Using the Pro35 unit means you have crummy depth of field all the time, even when you NEED depth of field.

The unit is clever in its design, I suppose, but provides an answer to a problem that doesn't really exist, in my opinion. I mean, the only 35mm films I see that exhibit shallow depth of field all the time are low budget films where the lighting packages are too small for the format. So the Pro35 unit really emulates the look of a low budget 35mm film since big budget 35mm films seem to have depth of field any time they need it.

Roger

[MovieStuff]

Actually, there is one thing that you do get with this unit and that's more dramatic wide angle shots because a wide angle lens really shows up well in larger formats as opposed to smaller formats. But, again, seems like a lot to give up for something so rarely used.

Roger

[mattias]

the only 35mm films I see that exhibit shallow depth of field all the time are low budget films where the lighting packages are too small for the format.

i disagree. shallow dof is used all the time for effect. enemy of the state is just one big budget example. it's clearly more of a style decision than a budget one. or did you mean that only the low budget ones use it *all the time*? if so i don't really see your point because you don't *have* to shoot at wide apertures and get super shallow dof with these devices -- but you can.

one more thing: these adapter lets you use lenses that are probably a million times as sharp as the ones commonly used on the xl-1, and the lens inside the device itself is highly optimized for imaging off the groundglass only, so the "loss of sharpness" is probably compensated for to a large extent. not to mention that these are real movie lenses which you can easily pull focus on and attach various follow focus gadgets to, unlike the "video lenses" commonly used. oh, and you have full control over dof independent of the lighting, since you have two apertures to play with of which only one affects the dof.

/matt

[john jay]

Hi Mattias

To some extent the tomfoolery with 10mm DOF at the beginning of "Swordfish" is tongue in cheek.

My understanding of shallow DOF in Cinematography terms is to direct the viewer to key parts of a scene without the distracting background, for example to add weight when the lead actor has an important line to deliver, in a figure and ground philosophy.

For my part I love projected S8, and the notion of being able to make it look like a 35mm movie would be a desirable thing. (eg make it look like a S8 dup off a 35mm movie) I feel the homemade approach to such an adapter may be the only way for us for cost reasons.

So if anyone has ideas how to produce a low cost high quality unit let them speak.

Regards

[MovieStuff]

i disagree. shallow dof is used all the time for effect.

Yes but all the time "for effect" is not quite the same thing as all the time "whether you want the effect or not"!

or did you mean that only the low budget ones use it *all the time*?

I mean that big budget 35mm films have adequate lighting packages and the time to implement them. Therefore, they have shallow depth of field only when they want it. Low budget 35mm films usually have thin lighting packages and are more often forced to endure shallow depth of field, even when they don't want or need it.

if so i don't really see your point because you don't *have* to shoot at wide apertures and get super shallow dof with these devices -- but you can.

But if you want better depth of field, you will need more light using this device than without. I mean, to me, it seems easier to remove ND from a standard video camera than to add lights, which is what you have to do with this do-dad when you do want more depth of field.

one more thing: these adapter lets you use lenses that are probably a million times as sharp as the ones commonly used on the xl-1, and the lens inside the device itself is highly optimized for imaging off the groundglass only, so the "loss of sharpness" is probably compensated for to a large extent.

Okay, let's pretend that the 35mm lenses help to offset the degradation of the image by the ground glass. Certainly you'd agree that the image can't be BETTER than it would without the ground glass? Ground glass just doesn't have that degree of resolution at all. Again, the images I saw looked much softer using the device than without. Of course, that doesn't mean it can't look nice, (even though what I saw certainly didn't).

not to mention that these are real movie lenses which you can easily pull focus

Good thing, since you'll be pulling focus all the time unless you pump the set with a butt load of light. The ability to pull focus is more of a necessity than a benefit, I'd say. Again, I personally feel that increased depth of field is one of the best things about smaller formats like video or super 8 and that achieving shallower depth of field can be addressed with simpler methods.

and you have full control over dof independent of the lighting, since you have two apertures to play with of which only one affects the dof.

Yeah, kind of like the two position lamp switch on Elmo projectors.

"You know, honey, this image just isn't dim enough for me. Better cut that switch down a notch." ;)

Roger

[mattias]

well, i think the large dof of video cameras and super-8 is easily their biggest problem, while you think it's their biggest assett, and aside from that we seem to agree on the technicalities. :-)

and you have full control over dof independent of the lighting, since you have two apertures to play with of which only one affects the dof.

Yeah, kind of like the two position lamp switch on Elmo projectors.

"You know, honey, this image just isn't dim enough for me. Better cut that switch down a notch." ;)

no, not at all. the point is that if you have lots of light, which you often do outdoors for example, and still want a shallow depth of field you can open up the front aperture, which controls dof, and close the rear, which affects only exposure, and vice versa.

/matt

[MovieStuff]

the point is that if you have lots of light, which you often do outdoors for example, and still want a shallow depth of field you can open up the front aperture, which controls dof, and close the rear, which affects only exposure, and vice versa.

Ah, but I've never been on a 35mm shoot, indoors or out, where there was the feeling that they had "lots of light" to work with. Depth of field for 35mm is so shallow that it is one of the things that the DP is constantly fighting to gain, even outside.

I think that there might be a perception that I am suggesting things should be in focus from the front lens to infinity or something when I talk about the benefits of increased depth of field on smaller formats. It can be that way but doesn't have to be. But the *size* of the area you want in focus will be easier to maintain in a smaller format than in 35mm. With smaller formats, it's really just a matter of removing lights or adding ND filters, both of which are cost and time effective. Using the Pro35 adaptor means adding more light to the package, just to achieve *reasonable* depth of field to begin with, since the unit itself eats up a considerable amount of light on top of the needs of the 35mm lenses.

I do realize we are talking about stylistic choices. I just find the whole idea of the Pro35 kind of a contradiction in concepts. Many of the proponents praise the idea (though most have not actually seen it in action) by saying that it will give their projects the characteristics of a 35mm production. But the question is what KIND of 35mm prodution? A big budget production or a low budget production? Adding the Pro35 to the front of the video camera doesn't magically add more money to the lighting package or increase the size of the crew or add more time to the shooting schedule. And, frankly, if you HAVE these resources accounted for, then why in the world is your project going to miniDV?!!!

Like I say, the idea of the Pro35 seems like a contradiction in concepts to me and works against what I feel are the inherent benefits of video and smaller formats. Didn't the inventors ever hear of ND filters?

Roger

[mattias]

Ah, but I've never been on a 35mm shoot, indoors or out, where there was the feeling that they had "lots of light" to work with. Depth of field for 35mm is so shallow that it is one of the things that the DP is constantly fighting to gain, even outside.

but we're not talking about 35 mm here, we're talking about video. this device is designed to get less dof on video, not to get more on 35 mm, right?

Didn't the inventors ever hear of ND filters?

video has lots and lots of dof even wide open.

/matt

[MovieStuff]

but we're not talking about 35 mm here, we're talking about video. this device is designed to get less dof on video, not to get more on 35 mm, right?

Correct. But you can't transfer the benefits of shooting in 35mm without also inhereting the problems.

video has lots and lots of dof even wide open.t

Well, again, we are talking about subjective choices. Still, I've worked on lots of video projects where we simply added ND to achieve depth of field that was shallow enough to convey the feeling the director wanted. The choice of focal length also comes into play. Using longer lenses to achieve isolation is very common, in both larger and smaller formats, and doing so combined with ND filters will cut the depth of field more than enough for smaller formats.

Now, if the desire is to have shallow depth of field on wide angle shots in video, then I guess you'd have to use the Pro35! Or, better yet, simply use a real video camera instead of a prosumer cam like the XL1. Broadcast cams generally have a backfocus that will let you suck up and modify the infinity setting for the lens. We've done that many times to give a scene the "35mm" look without resorting to things like the Pro35 do-dad.

But, really, I haven't found DPs on 35mm shoots often wishing for less depth of field on wide angle shots and, in fact, generally go to shorter focal lengths to GAIN depth of field, something easy to do in smaller formats when you need to.

Roger