Depth of Field

Krzys

Member

Joined

May 28, 2009

Messages

505

Location

Brisbane, QL

Format

35mm

• Jul 28, 2009

• #1

I seem to have fallen in love with f/4 on my Canon 50mm f/1.4 FD. My question is that what aperture on my (medium format) Mamiya Sekor C 80mm will give the same depth of field as the (small format) 50mm at f/4 and what is the sharpest point for the lens?

 

Herzeleid

Member

Joined

Oct 31, 2008

Messages

381

Location

Ankara/Turkey

Format

Multi Format

• Jul 28, 2009

• #2

I find this site quite useful for DOF, www.dofmaster.com
No idea with Mamiya Sekor.

 

Rolleijoe

Member

Joined

Dec 16, 2004

Messages

524

Location

S.E. Texas

Format

Medium Format

• Aug 3, 2009

• #3

Those lenses are totally different. So their bokeh won't exactly be the same. Experience is the best teacher, just shoot a roll and see if it gives you want you're looking for.

 

elekm

Member

Joined

Sep 12, 2004

Messages

2,055

Location

New Jersey (

Format

35mm RF

• Aug 3, 2009

• #4

I agree. It might be f/5.6 or f/8, but either way, different lens designs will yield different characteristics. It's one of those things that you'll only learn through experience -- often known as trial and error (or in my case, just error).

 

Nicholas Lindan

Advertiser

Advertiser

Joined

Sep 2, 2006

Messages

4,245

Location

Cleveland, Ohio

Format

Multi Format

• Aug 3, 2009

• #5

The same DOF at ~f6.8, but experiment with a roll of film and find the one you like the best.

Optimum resolution should be around f11 +/- 1 stop. Print out a resolution chart and put it in the test roll you shoot, above. Finding the best aperture doesn't require anything fancy in a resolution chart, it's pretty obvious where the sharpest apertures are.

 

mweintraub

Subscriber

Joined

Dec 22, 2008

Messages

1,730

Location

Dallas, TX

Format

Medium Format

• Aug 7, 2009

• #6

Plus the distance from the subject changes the DOF.

 

ic-racer

Member

Joined

Feb 25, 2007

Messages

16,546

Location

USA

Format

Multi Format

• Aug 7, 2009

• #7

A good rule of thumb is to match absolute aperture size; ie around 12mm. You can look in the lenses side-by-side and get a rough guide. You can also calculate it as others have indicated (around f6 to f7 on your 80mm).