Gaining shallow depth of field

[Mj882]

I tested the Letus35 Elite outside yesterday for the first time. I'm still learning how to use it and need to work on several areas; I have a few questions;

1. How do make the depth of field shorter, so it goes even blurrier. I increased my aperture size, but it seems limited, do I really have to be that close? I used a 50mm lens by the way. I'm aware that the closer you are, the more shallow depth of field, is it not possible to have a really blurry background and whilst subject in focus, from a medium distance?

2. I didn't touch the backfocus, I'm unsure on what exactly it does. On the Letus35 Elite its a simple ring, so the procedure is easy but I don't quite know what its for.

3. I hadn't turned the Letus35 on, and still managed to get slight depth of field. Could someone tell me what difference it makes on the quality when its turned on.

4. I shot in 720/24pn, however when I export the image looks grainy, the subject doesn't seem completely in focus and it also appears squashed. Any advice on settings?

I made sure I setup the focus before shooting. I use a HPX171e, thus prior to shooting I focused on the ground glass until it was grainy and sharp in focus, then clicked the Iris switch to hold it in place.

Help on my question would be much appreciated, here's an excerpt of my test footage (with MB effects):

http://www.youtube.com/watch?v=scm9uUd2vHs

Thanks

[Richard J. Johnson]

Did you focus on the ground glass with the lens OFF of the adapter?

Make sure your HPX is set to manual focus and when you focus on the GG make sure you lock down the focus ring.

I'm not too sure about the LCD on the HPX but if it's anything like the HVX It is VERY difficult to obtain precise focus using just that. It is possible though.


If you do not turn the adapter on you will be able to see the ground glass and it ruins your image. If you have low batteries in the adapter the GG wont vibrate fast enough and you could still see it.

And with a 50mm lens sometimes you have to get really close depending on the look you wish to achieve.

Also Having the correct amount of light is crucial it getting it to look good. If you search the 35mm adapter thread here you will find every answer to all of your questions. That's what I had to do. good look and have fun with it.

[Mj882]

Did you focus on the ground glass with the lens OFF of the adapter?

Make sure your HPX is set to manual focus and when you focus on the GG make sure you lock down the focus ring.

I'm not too sure about the LCD on the HPX but if it's anything like the HVX It is VERY difficult to obtain precise focus using just that. It is possible though.


If you do not turn the adapter on you will be able to see the ground glass and it ruins your image. If you have low batteries in the adapter the GG wont vibrate fast enough and you could still see it.

And with a 50mm lens sometimes you have to get really close depending on the look you wish to achieve.

Also Having the correct amount of light is crucial it getting it to look good. If you search the 35mm adapter thread here you will find every answer to all of your questions. That's what I had to do. good look and have fun with it.

Yeah the lens was off when I focused the ground glass. The HPX was also set to Manual whilst focusing.

I'm going to do another test with the Letus on.

Ah yeah I'm aware of the importance of lighting, however for this particular attempt it was in the morning and I'm sure there was sufficient natural light.

So what lens would you recommend for more shallow depth of field, even from a certain distance? Or does the light determine that?

[Shibuya Oboya]

While you can get pretty shallow dof with the 50mm all the way open, lenses that are telephoto will shorten dof more without needing to be close to the subject. like 85mm, 100mm, and so on. alot of people like having a good manual zoom lens.

image being squashed sounds like something not being set right in whatever program you edit with.

the adapter needs to be turned on to hide the grain. it doesn't have anything to do with your dof.

[Mj882]

While you can get pretty shallow dof with the 50mm all the way open, lenses that are telephoto will shorten dof more without needing to be close to the subject. like 85mm, 100mm, and so on. alot of people like having a good manual zoom lens.

image being squashed sounds like something not being set right in whatever program you edit with.

the adapter needs to be turned on to hide the grain. it doesn't have anything to do with your dof.

Should I opt for a 105mm Macro f/2.8 or a 105mm Telephoto f/2.5? (Both AI-S)

I do want some detailed close-up shots, as well as shots that would have noticeable shallow depth of field without needing to be too close to the subject.

[Shooter]

Yeah the lens was off when I focused the ground glass. The HPX was also set to Manual whilst focusing.
....
So what lens would you recommend for more shallow depth of field, even from a certain distance? Or does the light determine that?


Longer lenses have a shallower depth of field. Wider lenses have more DOF.
Wider apertures (less light situations) = less DOF.
Narrower appertures (more light situations) = more DOF

Focal length of lens and amount of light are both considered together to achieve the desired result. (althought it is only part of the desired result)

IMHO:

DOF is NOT the most important consideration in cinematography. The "story" comes first followed by lighting, composition, framing, DOF, blocking, framerate, shutter angle etc...
(in no particular order)

[Huy Vu]

The amount of blurriness of the background depends on the focal length, the background's distance from the subject and the aperture. You can of course use a longer lens but the effect is not the same as long focal length compresses the background, bringing it closer to the subject. This can create a very claustrophobic effect or an unnaturally size background relative to the subject. That's why getting the BG out of focus isn't the only consideration you should make.

[Shooter]

Well caught Huy Vu

"the background's distance from the subject "

a very good point that I missed.