Wide aperture - Pictures out of focus

Started Aug 3, 2014 | Discussions thread
tedolf Forum Pro • Posts: 27,130

Truthiness wrote:

tedolf wrote:

Truthiness wrote:

tedolf wrote:

Jizzy wrote:

tedolf wrote:

So, stop down to about f/8 and you will get a DOF of about 8-10 inches.

Now, you have to ask yourself why did you spend so much money for a f/1.8 lens when you really can't use it wide open for the types of photo's you want to shoot!


Yeah, thats what I am asking myself now

with lenses shot wide open (higher shutter speeds, lower ISO) the u 4/3 format is probably ideal.

No one forces one to shoot wide open. You know, it's perfectly fine to stop down. Typically the optical properties improve then too.

Except when you need the higher shutter speed.

f/4 on FF equals f/2 on m43.

For DOF purposes yes.  That is my point.

So I can use the same shutter speed on FF with f/4 I can at f/2 on m43.

This is absurd.  The exposure value is different by two stops at the same shutter speed.

The only way you can do this, and keep the shutter speed the same is to increase ISO on the FF camera by two stops.

Your argument is not rational.

There is something very fundamental you do not understand about exposure

Personally I would find m4/3 too limiting for portrait photography.


It doesn't offer enough separation when the background is not far enough and the subject is not close enough. That is just a personal thing, nothing objective.

Look at some DOF tables for portrait FOV lenses for the two formats (say 85mm for the FF, and 45mm for the 4/3 sensor) and see which one has the more usable DOF profile.

There is nothing ideal about m43 in this use case, far from it. Are you sure your personal attachement to m43-system is not clouding your judgement?

My personal attachment is absolutely clouding my judgment. Portrait photography is exactly why I chose the 4/3 format.

4/3 offers ZERO advantage for portrait photography when it comes to image quality. If you think it does, please inform me how (other than IBIS in some cases when the subject is really still and the shutter just has to be slow with enough DOF).

Good God, do you have the capacity to follow an argument? DOF is part of image quality.  Did you see the OP's original picture.  You can not get the full head, front to back in focus on a tight head and shoulders shot using a FF camera at ten feet with an 85mm lens at f/1.8.  The DOF is only 3 inches.

What about that are you incapable of understanding?

Also, the sensor aspect ratio is a better match for printing than the 3/2 format so you aren't cropping so much.

Are you serious? 3:2 is very common ouput format, certainly more so than 4/3.

It is, but the 3:2 format doesn't match 8" x 10", 11" x 14", 5" x7" or 8.5" x 11" nearly as well as 4/3 does. Those are common print sizes in the U.S.

But so is 3:2. You're cherry picking the print sizes you like.

Those are the standard print sizes in the U.S. The only print size in the U.S. that matches a 3:2 aspect ratio is 4" x 6" (hardly an enthusiast size print) and 20" x 30", which hardly anybody prints on a regular basis.

Today all kinds of print ratios are very common.

Really? Have you ever worked at photo print shop?  Do you have any idea what size the most common large print is?

I will save you the research: in the U.S. it is 8" x 10".  In the UK it is A4.

And in the cases you're more interested in not printing, but using a computer screen, 4:3 is hardly optimal.

The vast majority of computer screens actually in use today is 4:3.  The next most popular size is 16:9 which matches neither 4/3 or 3:2.

With the camera you have, f/4 is about as wide open as you can go for a head and shoulders shot and your focus placement has to be perfect.

It is worse with FF if that is any consolation.

Lenses can be stopped down.

Unless you need the higher shutter speed.

But f/4 on FF is the same as f/2 on m43. If f/2 is wide open on both, then only FF can get more shutter speed from that point on.

Except you can't use f/2 on a FF for a tight head and shoulders shot at 10 feet with an 85mm lens.

The DOF is too narrow.

How many times do we have to go over this?

If you want to shoot wide open portrait length lenses at base ISO, the 4/3 crop factor and aspect ratio is an advantage.

Why you insist wide open?

To get a faster shutter speed.

Please, try to keep up!

Assuming same f/# Wide open on iPhone is not the same as wide open on FF, is it?

No it isn't.  That is the point I am making!

Nor is wide open on m43 is not the same as wide open on FF (assuming same f/#).

Yes, finally you are getting it!

Aspect ratio is disadvantage for digital output mediums (TV, monitors) for m43, for printouts it's irrelevant as all formats are very widely available.

Depends on your TV.  My Sharp Equos LCD TV is 4:3.

When you shoot with different formats, do you first decided that "ah, I'll shoot this wide open", regardless of what "wide open" means with the system?

Yes, if you are in a dark environment and need the light or if you want to shoot at base ISO.

FF is no worse than APS-C

Mostly true.

For portraiture there is nothing APS-C can do, FF can't. On the other hand FF can do more. Thus FF is better for this purpouse.

or your belowed m43 for this kind of use.

Not true. See above.

You offer no logical reason for your argument.

See above, I am not going to repeat it again.

The printout-reason isdemonstrably false -


I even checkoud out typical US based photolabs and they all offered all kinds of output formats on all sizes.

Tell me what these U.S. 3:2 print out formats are, other than 4x6 and 20x30?

I will give you a hint.  York Photo is the largest photo printer in the U.S.

This alone makes you sound like biased for your favorite brand or format.

The "wide open" logic is just silly.

Now I am not following you.  The maximum aperture of a lens is often the first thing a photographer considers after deciding on a focal length for purchase.

Should you fist decide what kind of photo you take, and then choose the appropriate aperture instead of just blindly taking "wide open" which creates different results with different formats.


For the reason FF is better for this job than APS-C it's better for this job than m43.

Except that it isn't.  Just like medium format is no longer superior for portraits over FF once FF resolution became high enough for good large prints.  Almost no on is using medium format for portrait work at the large commercial portrait studios (e.g. Yuen Lui) anymore.  First of all, it is too expensive, and by using larger apertures possible with the 35mm format you don't have to use such powerful lighting, etc.

If it ever becomes necessary to replace the lenses, I wouldn't be surprised if commercial studio's switch to APS-c or 4/3 sensors.  The real problem with APS-c is that the best lenses are still made for FF format.



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