FORUMS: list search recent posts

shallow dof lens for alfa 7s

COW Forums : DSLR Video

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
doriana zuolaki
shallow dof lens for alfa 7s
on Aug 13, 2015 at 7:34:57 pm

Hi, I'm new on this forum. I'm a amateur cinematographer and until now I've worked with amateur camcorders. Now I'm about to buy Sony a7s and as I don't know much about world of lenses I would like to ask you people for suggestion of a lens for a7s.
What I would like to have is
- good image stabilization
- shallow depth of field
- zoom
- if possible light and small (least priority)

Doriana


Return to posts index

Steve Crow
Re: shallow dof lens for alfa 7s
on Aug 14, 2015 at 1:41:18 am

The first question to ask is what will you be filming? Sports? Documentaries? Dramas?

Outside of shooting sports, I think a great first lens would actually be a either 35mm or 50mm prime lens. I'd first get a 50mm as that is the "classic" movie focal length and is very versatile , in my opinion, and then get something wider to go with it - either the 35mm or maybe even a 24 (25?)mm for your wide shots. There are many models to choose from that will fit the bill. Yes, they can get expensive and so budget is going to dictate your choices.

Canon is very well respected for their lenses but you have other manufacturers to select from. You will have to get an adapter to fit non-Sony brand lenses on your A7s but those are available and relatively inexpensive.

To start off you can always just get a 50mm prime and then rent whatever else you may occasionally need.

I'm not against zooms at all, in fact many would probably point out that a 24-70mm is a great option for lots of uses and if you are shooting sports then a zoom would make a lot of sense. Ideally you want a lens with a constant aperture of say 2.8 or wider. If you have a zoom lens, then a constant aperture model won't darken the image as you zoom in. For a prime lens you're obviously not zooming.

Steve Crow


Return to posts index

Steve Crow
Re: shallow dof lens for alfa 7s
on Aug 14, 2015 at 1:49:03 am

Oh and if you want to be one of the really cool kids :-) then buy an old vintage lens (are there "new" vintage lenses?)

They will most likely be all manual so you will set focal length, focus and aperture all by yourself but there have been many experienced cinematographers who swear by the old glass and the unique looks they are able to achieve with them.

Frankly, a lens I am excited about doesn't even work on a DSLR type camera - it's made for the iPhone and gives you an anamorphic perspective just like big budget movies from Hollywood. (check out Moondog on Google)

Steve Crow


Return to posts index


Steve Crow
Re: shallow dof lens for alfa 7s
on Aug 16, 2015 at 12:17:52 am

Just as a last note - you may want to check out my Flipboard magazine on DSLR Filmmaking as I recently linked to several articles on lenses, including some new options in the cinema lens category that may (or may not) be out of your budget range but are none the less very interesting. I can't afford owning them myself but I like knowing they are available.

Go to:


https://flipboard.com/section/hd-dslr-filmmaking-byqgog

Steve Crow


Return to posts index

doriana zuolaki
Re: shallow dof lens for alfa 7s
on Aug 16, 2015 at 1:46:09 pm

Thank you Steve for all responses. That made me sure I'll go for constant apperture, but as I'm filming mostly festivals so portability and zoom are important for me so I'll check out 24-70mm you suggested. Does apperture allows good artistic s dof?

I'll certainly check out your flipboard.


Doriana


Return to posts index

Steve Crow
Re: shallow dof lens for alfa 7s
on Aug 16, 2015 at 3:38:49 pm

Doriana,

Basically if you are at an aperture of 2.8 or wider (1, 1.4, 1.8, 2, 2.8) you will get that blurred background or shallow depth of field.

Here's a thing to keep in mind though - the blurred areas look like that because they are out of focus of course. That means you really have to get your focus right on your subject AND if they move you have to refocus because a shallow depth of field is just another way of saying shallow focus. How "deep" your focus is determined by factors like how far away your subject is, the lens aperture and by what your lens focal length is - 24mm, 70mm or somewhere in between for instance.

At very wide open apertures, the smaller numbers, the depth of field may be an inch or even less, meaning if you focus on the performer's eyes, their nose may be out of focus. So if they move too much towards or away from you, your shot could be ruined. So you may find that shooting performers on stage who are always moving with a shallow depth of field is just too hard - in that case set your aperture to a high number (or more closed down in the language of photography.) Setting your aperture at 8 is usually more than safe enough to get everything in focus.

There are paper and online calculators and even apps for your phone that will tell you what your depth of field will be after you input your camera's settings.

Steve Crow


Return to posts index


Jason Jenkins
Re: shallow dof lens for alfa 7s
on Aug 19, 2015 at 5:26:14 am
Last Edited By Jason Jenkins on Aug 19, 2015 at 5:26:49 am

This is a really nice lens I've been shooting with today:

http://www.bhphotovideo.com/c/product/1001009-REG/sony_sel1670z_16_70mm_f_4...

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


Return to posts index

doriana zuolaki
Re: shallow dof lens for alfa 7s
on Aug 21, 2015 at 7:38:01 am

Thank you Jason for your response.
I guess that max apperture f/4 doesn't give much sdof ( thats a must for me ) . And how is stabilization doing? Is it strong enough to shot videos handheld?

Doriana


Return to posts index

Jason Jenkins
Re: shallow dof lens for alfa 7s
on Aug 21, 2015 at 4:10:16 pm

[doriana zuolaki] "I guess that max apperture f/4 doesn't give much sdof ( thats a must for me ) . And how is stabilization doing? Is it strong enough to shot videos handheld?"

Doriana:
I did a short test so you can see the DOF and the handheld look with steadyshot on. You can download the file here: http://1drv.ms/1NAnBke

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


Return to posts index


Aaron Star
Re: shallow dof lens for alfa 7s
on Aug 21, 2015 at 8:42:45 pm
Last Edited By Aaron Star on Aug 21, 2015 at 8:43:42 pm

If your image sensor is around 35mm, a 35mm at F4 will give you a soft background. Be careful shooting to wide open, as your DoF gets so small that you risk a lot of soft shots to cut around. Hand held large sensor shooting is generally best with an AC pulling focus, as most cameras prosumer suck at smooth follow focus. Also shooting WFO, most lens will soften up, that is why most DPs shoot around 4 or above. That is not to say you do not want a T2 lens to starter with, as the faster lens generally means better construction.


Return to posts index

Steve Crow
Re: shallow dof lens for alfa 7s
on Aug 21, 2015 at 4:21:47 pm

I think you should consider a monopod. Having a fairly steady shot, particularly if you relatively far away from the performer on stage, is going to make focusing accurately much much easier for you.

Steve Crow


Return to posts index

doriana zuolaki
Re: shallow dof lens for alfa 7s
on Aug 22, 2015 at 9:27:06 pm

Thanks so much Jason
The example you did makes me want this lens - boekh is nice and IS is good too - this might be my first lens then. Anyway as I don't have a big budget I'll keep searching and learning before final decision.

About focus issues Aaron mentioned ... Jason did you noticed and difficulties with follow focus on A7s when shooting wide open?
Also I'm considering having an AC with a smartphone connected trough wifi - is it possible with A7s to control focus this way?

Steve - about external stabilizer - I decided to go for an electronic 3axis gimbal - most likely Nebula 4000 ( still to choose among alternatives - beholder and pilotfly h1 ) .


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]