Disappointed in Redrock M2 adapter
 

Boy, I know it's been a while since I've been here but since starting my own biz it's been 18 hour days. Listen, I have a question. At NAB I saw what I thought was the answer to my problems. At the JVC booth there was a Red Rock M2 display that had this converter that not only allowed me to use prime lenses but gave me great depth of field as well. When I talked to the RedRock people they told me that's the beauty of the Red Rock...great DOF. So I get one and put it on and NOTHING. I mean my primes fit but the depth of field is just like it always was...long and crystal clear. Has anyone else had this problem? I was promised that the M2 wuold give me film-like DOF but it doesn't. Anyone?

DOF is also affected by which prime you're using, distance from subject and your aperature settings. If your fstop is set around F4, you're using a "normal" lens (not super wide) you should have a pretty shallow DOF. If you're using a very wide prime and small aperature (F8 or 16 for example) you'll still have deep focus.

Give us some more particulars on your set up.

First, Warren, hey. Back on the board after those hellish weeks and pony-shows. And Joyce, my Joyce says Hi. Now, to your issue. We used the M2 with a standard 50mm lens and experienced the same thing. In point of fact, I spoke with a number of people I met at the JVC booth and everyone is experiencing the same problem which is why "24" is having issues with the 1/3" cameras; DOF. The M2 and the PS Teknik both allow the use of primes but, until I saw the Red Rock demo at NAB, I thought that neither addressed the DOF issue. When I saw the Red Rock though, the DOF was great. I could rack focus from the table to the bookcase and the fern, all within a few inches to a couple of feet of each other and that was with a stock, older 50mm Nikon (I took notes). Excited, I came back to LA, told alot of people about how a $1000 box beat a $10,000 box and borrowed a Red Rock and 50MM Nikon to prove my point. How embarassed was I? I couldn't replicate the DOF I saw the Red Rock produce either. So, in short, I don't know what to tell you except that I'm having the same issues. So, Warren, given she was using a 50 like I did, what's the answer. You were at NAB and I think saw the RedRock demo. What do you think?

Have you guys thought about going directly to the source -- and asking this question on Redrock's message board? After all they are the best people to help you, since they built that thing. The link is:

http://redrockmicro.com/forum/index.php

Chris- Thanks. I didn't know about that board. Your work makes so many of our lives easier. Thanks.
Jonathan

Ditto. Thanks for the heads-up. I'll check over there. Now it's back to the dungeon for me!

I suspect it's just like the HD100 stock lens--if you create the right conditions, you can get a shallow DOF with it. It's just lots harder. The whole point of the Red Rock is to simulate the base conditions of a 35mm lens but it won't automatically be shallow. Without having my hands on one, I suspect it will take some knowledge and practice to get the look you want but I've seen that you can get it. With a 50mm lens I think you'd need to be fairly close to the subject with the lens wide open. Nate and Tim would know better what conditions are needed.

It may sound obvious, but check to make sure you've got an open iris on the prime lens you're shooting through. Set the iris on the prime for the DOF you want, then use the iris on the "master" lens (presumably the HD100 stock you've attached the M2 to) to set exposure.

Joyce, what lens are you using with the M2?

Jonathan, over in a post in another thread you mention that Taylor Wigton came over and showed you "a great solution" to this problem. For the benefit of everybody else here who might encounter the same trouble, would you mind sharing with us what that solution is?

I haven't worked with the Redrock, but as an early adopter of the Mini 35, I can tell you that it absolutely addresses the DOF issue. In fact it creates the exact dof and fov of a 35mm format camera.

I was surprised to read from Taylor and from another friend here, both with experience with the M2 and the Mini35 that the M2 was actually preferable in image quality and light transmission to the considerably more expensive P&S, so much so that I decided to setup an HD100 with a M2 for our dramatic work. In fact I'm just about to order a setup today.

So, without the M2 expereince but a ton of Mini35 experience all I can suggest is operator error or not enough experience in working with the sysytem. I'm assuming that, aside from the upright image that the P&S system provides, that the prinicple is essentially the same, and that is to project the image from a traditional 35mm lens onto a screen that "rear" lens then focuses on and sends to the 1/3" CCDs, thereby providing it with all of the characteristics of the front 35mm lens.

As has been suggested, proper iris settings (on both lenses) and proper distance to subject and background/foreground are the essential ingredients, and they should be exactly the same as shooting with any 35mm format camera - still or motion.

Jonathan and Joyce, if you really can't duplicate what you saw at NAB, drop me an email and I'll be glad to give you a quick primer on getting the shallow dof that you should absolutely get from your system...we can get on the phone for a bit if it would help.

Of course, Chris. I'm grabbing a quick early lunch here in the coach and checking e-mails while the crew is setting up so let me do that this evening when I get home. I took some notes on the things he was doing to pass along to the camera guys here and without those, I'd probably screw the methodology up.
Jonathan

The thing is, as you are filming an image projected on a ground glass by a 35mm lens, there's no way you wouldn't get the exact same DOF from that lens as you would if it was mounted on a 35mm camera. As simple as that. The problem is not the M2.

The problem is either (1) they are shooting with a wide prime lens like a 35mm or a 28, or (2) Aperture on the prime lens is shut way down the f stop scale to F 16 or F11. They need to shoot with the lens set at wide or near wide open aperature ( F 1.2 to F 2.8), in order to have a maximum shallow depth of field.

Either way, they would get the same DOF if they were using a film camera and doing the same things they are doing now with the M2. That was my point. But you are right. It's either focal length, aperture or both.