View Full Version : Do I need an F1.8 lens v. F2.8?


Dave Allen
November 28th, 2013, 09:12 PM
I have a Sony Zeiss 16-35 zoom that works quite well during the day, but have not had a chance to test it for real low light work.

Sigma has a new 18-35 zoom that is fast at F1.8. The zoom range quite overlaps the Sony Zeiss lens I have. The Sigma is also $1000 USD less expensive.

Has your FS700 sequences in really low light like candle light worked out well with an F2.8 lens without an ISO so high as to add too much noise, or do you think the Sigma Art F1.8 lens night be a better low light choice, or even all around choice. I hate buying a new lens whose focal length overlaps what I already have, but I really want to nail low light.

Stephen Brenner
November 29th, 2013, 07:41 AM
I can't speak for how it relates to an FS700 since I'm using a Black Magic Pocket camera and a NIkon D600, but it seems to me that unless you find the image characteristics of the Zeiss lens so special that you need to keep it, the new Sigma apparently is so extraordinarily sharp (even at f/1.8) that if you could sell the Zeiss and get the Sigma and have money to spare, you'd have very little tradeoffs. It's nice to have that low light capability when you need it. But then you also have the decreased DOF issue which may be a plus when you need it, but a hassle in focusing when you don't. In most cases, it really just gives you more options (since you can always stop down).

Bill Kerrigan
November 29th, 2013, 11:18 AM
I haven't used candle light with the 700 yet... but I'm pleased with it's ability to shoot in low light.
One of my fav lenses for interviews, is the Rokinon Cine 85mm T1.5.
I'm able to shoot in a small room... and keep the BG soft.
I was considering buying the Rokinon 24 & 35mm T1.5 Cine Lenses, until I read about the Sigma 18-35 F1.8.
Recently, I bought a Sigma 70-200mm F2.8, and I'm impressed by it's image quality...

I'm planning to wait for the 18-35 A mount version, then compare the 3 lenses.
If it's as good as the reviews, I may sell my Sony 16-50 F2.8.

I'd be very interested in knowing what others are using...

Here's what in my lens bag:
Sony 16mm Pancake, Wide Angle / Fisheye - extreme wide and handheld shots.
Sony 16-50 F2.8, - wide and handheld shots.
Zeiss 28-70 F2.8 - main lens on the tripod.
Sigma 70-200mm F2.8 - interviews and telephoto
Rokinon 85mm T1.5 Cine Lens - interviews and general use
Sony 18-200 kit lens - run and gun / face detection
Sony NEX 7 - B roll camera, stills camera and crash camera... instead of a GoPro.

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Bill Kerrigan
Montreal, Canada
http://www.kerrigan.ca

Paul Gale
December 1st, 2013, 10:41 AM
I've just used the SELP18200 on an interview setup - only had the camera since mid last week.

Was very impressed with the face detection - are there any other FASTER Sony lenses that offer this that anyone would recommend?

I also got the set of Samyang cine lenses which seem very good - 85mm as you say is great for interview work, maybe using it at around f4 for best sharpness? These are on the speedbooster.

Canon 24-105 f4 IS seems pretty good too with the speedbooster, although even faster would be good for extreme DOF.

Alister Chapman
December 1st, 2013, 03:38 PM
Paul if your having to stop down your Samyang to F4 to get it sharp something isn't right. Mine are all tack sharp from T2.8 and the sharpness drop off at T1.5 is barely noticeable.

Paul Gale
December 1st, 2013, 03:49 PM
I'll need to do some more testing then.

My 24mm lens has a sticky iris so that will go back this week for replacement.

Have the 14mm on order but not so sure about it now - a few not so glowing reviews compared to the others. What's your favourite super wide?

Bill Kerrigan
December 2nd, 2013, 08:06 AM
Paul if your having to stop down your Samyang to F4 to get it sharp something isn't right. Mine are all tack sharp from T2.8 and the sharpness drop off at T1.5 is barely noticeable.

My Samyang/Rokinon with an A mount is also tack sharp at 2.8.