DPReview.com is closing April 10th - Find out more

M.Zuiko 40-150mm F/2,8 lens + M.Zuiko MC-14 Teleconverter for Close-up Photography

Started Apr 11, 2016 | User reviews thread
CrisPhoto
CrisPhoto Senior Member • Posts: 1,749
Re: M.Zuiko 40-150mm F/2,8 lens + M.Zuiko MC-14 Teleconverter for Close-up Photography
2

woodybrown wrote:

For a given sensor size, when using different focal lengths if the distance is adjusted to equalize the FOV (or the magnification), then the DOF should be the same (unless the distance is close to the hyoerfocal distance).

It appears that you came up with a greater DOF for the 210mm thru an error in the distance you plugged in for the 210mm to get the same magnification as the 60mm. It should be 210 rather than 250cm.

M (FOV) = FL/Distance = 60mm/600mm = 210/2100.

At 210cm and 5.6 a 210mm FL gives the same DOF as the 60mm at 60cm which is 1.6cm according to the Cambridge in Colour online calculator that I am using.

Yes, for same size on the sensor the DOF is the same.

But you forgot the background magnification in you calculation. As the background is magnified around 3 times more, the bokeh can be quite "buttery" compared to the 60mm lens.

That's another reason to prefer a tele lens for macro: either you have more bokeh or (if you close the aperture) the same bokeh but more DOF which can not be enough for macro work.

Christof

-- hide signature --

OM-D + Sam7.5, O25, O60, O75
O12-40, O40-150, P 14-140

 CrisPhoto's gear list:CrisPhoto's gear list
Olympus E-M1 II Samyang 7.5mm F3.5 Fisheye Olympus M.Zuiko Digital ED 75mm F1.8 Panasonic Lumix G Vario 14-140mm F3.5-5.6 O.I.S Panasonic Leica DG Summilux 15mm F1.7 ASPH +9 more
Post (hide subjects) Posted by
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow