35mm adapters, DOF, and reality ?'s

[snodart]

I was hoping to get a little help...

First:
I recently built my own Ed35 (Edwierdo's static GG adapter) and am using it with my DVX-100b. Works great and has a nice shallow DOF. But...

I am limited to around f2.8 or f4 before I start seeing the grain from the Nikon D screen. I am pondering forking out the cash for one of the many moving GG adapters, but wonder if there would be that much of a difference in being able to close down the f-stop and achieve a deeper DOF. I am the focus puller and cam operator, so keeping focus on jib, steadicam, dolly, etc shots with a lot of actor movement is a challenge (no surprise).

Second:
For those of you who have utilized your 35mm adapters in making a short/feature...

Did you keep the adapter on the whole time, or only use it when you were seeking a shallow DOF?

If you were using a 35mm adapter, did you find that maintaining the focus was a major challenge in shots with actor/camera movement? How did you get around or accomplish these shots?

I know this is a loaded topic, but any help, experiences, or advice would be great.

[carlone]

I have the Redrock M2 Adapter. I use it with an assortment of Nikon's. Honestly it looks great. The shallow DOF and the ability to choose what you want the focus on is amazing .... but.

I'm starting to believe that it really depends on WHAT you're shooting, how many lights you have available, how much time will you have to frame your shots, lights and focus.

If you're shooting something where you have the time then it's an amazing enhancement to your production. If you're budget forces you to move quickly then sticking a 35mm lens in front of your camera "may" not be the right thing to do.

I've tried shooting some things with it and some without but the softness of the shots and the overall lens difference make it difficult to match the footage.

The catch is that after you get everything adjusted, you get some pretty amazing looking footage with the Redrock Adapter and you don't want to take it off.

[HansK]

I am the focus puller and cam operator, so keeping focus on jib, steadicam, dolly, etc shots with a lot of actor movement is a challenge (no surprise).
Tell me about it. I just finished filming a short with a M2 and without the use of a followfocus. One of the actors had a tendency to rock forward and back. It took me a bit to get the feel but it was still tough keeping up with him. Now if I had a follow focus it might not of been so bad.

You don't mention if you are using a FF.

Also, using a wider angle lens can help with and did help us for keeping more in focus. Only needed for a few shots.

Note, if you watch/listen to lots of director/DP commentaries on DVDs you will hear them talk about this problem and how they worked around it.


Did you keep the adapter on the whole time, or only use it when you were seeking a shallow DOF? Yup, the whole time. Trying to match shots taken without the M2 to shots with the M2 would be really tough.

For the look and feel I get from using the M2 it's worth the troubles of focusing. The image just looks great.

Btw - There's a few grabs from the short film I shot with the M2 over the in the grabs section:

http://www.dvxuser.com/V6/showthread.php?t=51859

[snodart]

Wow, great info HansK and carlone. Everything that both of you have said makes great sense. This is exactly the type of info I was hoping for.


You don't mention if you are using a FF.

I have a FF on the way.

Funny that you both have the M2, I have been considering buying one. 4-6 weeks is a long time though (before it is shipped).
:eek:

I'm curious, with the M2 and its small amount of recorded light loss, how far are you able to close down the f-stop on your 35mm lens before issues arise?



Note, if you watch/listen to lots of director/DP commentaries on DVDs you will hear them talk about this problem and how they worked around it.


I've watched quit a few commentaries. Are there any specific ones that you can think of that do a good job at addressing this issue?

[carlone]

I'm curious, with the M2 and its small amount of recorded light loss, how far are you able to close down the f-stop on your 35mm lens before issues arise?


Well, outdoors of course things get much easier. Outdoors I can put a .6 ND filter on front of the 35mm lens and vary the F Stop between 3.x and possibly 8 - depending on how much DOF I want. It looks great outdoors without much extra work on my part.

Indoors, for me this is where you'll have to work much harder. Typically you'll need to have the 35mm lens pretty much wide open (So having a fast lens should be considered a requirement). My fastest lens is a 50mm 1.8. Of course if you have the lens at 1.8 even the slightest movement of the actor and he's out of focus.

This is where having a wide assortment of lights comes in handy. Depending on the size of the room you'll need a minimum of (2) 650's and a couple of 300's to help bring up the overall level. Now you can run your F Stop closer to 3.x up to possibly 5.6. This makes the actors a little happier because they can have a little more movement and still be somewhat in focus.

It's all about give and take but there is potential for some beautiful footage (or some really useless footage that will need to be re-shot). Bottom line is plan to take much more time than usual.

[TimurCivan]

let me ask you, when youre using the M2, lets say youre shooting a F1.2 at wide open, instead of putting a ND filter over the 35mm lens, if you were to activate the DVX/Z1/XL2 's ND filters, wouldnt that create the same result? or does the GG "blow out" if theres too much light?

[snodart]

carlone, great info. Seems like the M2 allows for some pretty good DOF (narrow/deep) options compared to my static GG.

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[carlone]

let me ask you, when youre using the M2, lets say youre shooting a F1.2 at wide open, instead of putting a ND filter over the 35mm lens, if you were to activate the DVX/Z1/XL2 's ND filters, wouldnt that create the same result? or does the GG "blow out" if theres too much light?

Someone else will probably be better suited to comment with the true technical reason for or against an external filter vs. the built in ND filter. For my own personal taste, I like to use an external filter and attempt to get control of the amount of light "before" it hits the 35mm lens (or the internal lens for that matter). I use the camera ND filter only if I don't have my external filters handy.

There's a fine line between what you have the 35mm lens F Stop set to and what you have the camera (I use a DVX100a) F Stop set to. There's a sweet spot somewhere around (DVX set to 3.4 - 5.6) and the 35mm lens NOT set to extreme wide open or closed, somewhere in the middle gets a sharper focus (4 - 5.6).

Just my 2 cents - hell, I could be way off.

[HansK]

if you were to activate the DVX/Z1/XL2 's ND filters, wouldnt that create the same result? or does the GG "blow out" if theres too much light?
That's an ineresting question and one I hadn't thought about. I'm not usually letting in so much light that there might be artifacts generated from the GG. But it might occur. Personally, I would rather use the internal camera ND filter because the M2 eats up light. The more that can get through the M2 and into the camera the better. This is all personal choice though and I haven't compared image quality when using an external vs. internal ND filter.

[TimurCivan]

yeai was wondering about that, whether too much light on the GG fogs up the blacks, through dispersion.