Will the upcoming Oly 40-150mm f/2.8 be inferior in shallow DoF compared to the 75mm f/1.8?

[blindinglight]

The prime has bigger Aperture so I was wondering if I should just buy this now and save a bit more money. Of course the 40-150 has better focal length legroom but if we talk strictly bokeh effects/shallow DoF/background blur, will the bigger aperture prime still be a better glass for this case?

Thank you for the thoughts and opinions.

Keith

Edit: I'm using the E-M1 body.

 

[barry13]

At 75mm, the prime would win.

150mm is probably arguable.

Barry


Sent from my iPad using Mu-43

 

[blindinglight]

Thank you for the quick reply, Barry. So basically if I step back to maintain equal framing and use the 150mm at its longest, I might get better shallow depth of field than the prime (newbie lesson for me). That's good to know since having flexibility in focal length might after all make the newer Pro lens a glass to strongly consider for a bokeh whore noob like me . Thanks again.

 

[LowriderS10]

Use an online DOF calculator and plug in some random numbers.

At 75mm, definitely. At 100-125mm? They'll likely be close. At 150mm? Who knows...the 150 might edge out the 75. (Since 150 2.8 equates roughly to a 200 f4 on APS-C or a 300 f5.6 on full frame, you could always check out pictures made with those combinations to get a ROUGH idea on what sort of images you'd be looking at out of this lens at 150mm wide open).

 

[Klorenzo]

This should give you a rough indication of the blur amount (that is related to the dof)

http://howmuchblur.com/#compare-2x-75mm-f1.8-and-2x-40mm-f2.8-and-2x-75mm-f2.8-and-2x-150mm-f2.8-on-a-0.9m-wide-subject

 

[blindinglight]

Use an online DOF calculator and plug in some random numbers.

At 75mm, definitely. At 100-125mm? They'll likely be close. At 150mm? Who knows...the 150 might edge out the 75. (Since 150 2.8 equates roughly to a 200 f4 on APS-C or a 300 f5.6 on full frame, you could always check out pictures made with those combinations to get a ROUGH idea on what sort of images you'd be looking at out of this lens at 150mm wide open).

= 300mm f/5.6 for FF systems. Will jot down those figures, thanks. Yeah I like dofmaster calculator but was curious more insight from the photo community.

Thanks, Lowrider.


Edit: Klorenzo thank you for the awesome link.

 

[blindinglight]

This should give you a rough indication of the blur amount (that is related to the dof)

http://howmuchblur.com/#compare-2x-75mm-f1.8-and-2x-40mm-f2.8-and-2x-75mm-f2.8-and-2x-150mm-f2.8-on-a-0.9m-wide-subject

I updated your choices and narrowed the lenses down to two.

http://howmuchblur.com/#compare-2x-75mm-f1.8-and-2x-150mm-f2.8-on-a-0.9m-wide-subject

So basically, if the subject to background distance is 10 meters, they both have roughly/approximately (of course barring the quality of each lens) the same amount of background blur?

 

[Klorenzo]

So basically, if the subject to background distance is 10 meters, they both have roughly/approximately the same bokeh?

Yes, but only when you are filling the frame with the subject head and shoulders. There is a small selector above the chart to try other subject sizes.

Here you can find a few samples of what a X% blur should mean

http://www.dpreview.com/articles/6091822765/background-blur-and-its-relationship-to-sensor-size

 

[blindinglight]

Yes, but only when you are filling the frame with the subject head and shoulders. There is a small selector above the chart to try other subject sizes.

Here you can find a few samples of what a X% blur should mean

http://www.dpreview.com/articles/6091822765/background-blur-and-its-relationship-to-sensor-size

Wow, totally appreciate the info and the link.

 

[arch stanton]

Just as an aside, if you want to take a landscape full-length shot of someone (<6ft tall) with a 150mm lens you have to stand 70 feet away.
Bring a megaphone!

 

[blindinglight]

Just as an aside, if you want to take a landscape full-length shot of someone (<6ft tall) with a 150mm lens you have to stand 70 feet away.
Bring a megaphone!

Thanks. But of course people looking to buy these lenses already know the long focal length restrictions.

 

[eteless]

I think the 40-150 will be far better at 40-74 and 76-150, but at 75 the prime will always win.

You don't generally buy a zoom for bokeh (I laugh every time someone uses the word bokeh, I don't think that word means what you think it does... common usage aside), it's more for how it can work in a variety of situations and be very flexible. To get that flexibility you give up some performance, use the right tool for the right job - they're just different tools for slightly different situations.