Olympus High Resolution Mode test w/60mm macro

[austrokiwi1]

Does your Sony allow flash with the silent electronic shutter? I assume it is really silent and not EFCS? That is a huge advantage of the PEN F over most other cameras. An essential feature for me.

The Sony has Standard shutter, EFCS, and Silent shutter. I have just discovered flash doesn't work with the silent ( video scan) shutter.

Something I noticed with the Silent shutter. One issue with that shutter setting is when using mains powered lights with certain exposure settings, you get light and dark bands across the image. Unless your using the Oly OMD-Em10II, and I assume other models, seems the processor in the camera corrects the banding ( you can see the bands in the initial preview but once the image has been saved to the memory card they have gone

[ChrisR]

Wouldn't the "viewfinder" banding be interference/beating between the frequency of the flickering light source, and the scan rate of the display?

Perhaps the Sony also handles flicker like some Canon bodies - delayings the exposure to catch peaks.

[Lou Jost]

I have just discovered flash doesn't work with the silent ( video scan) shutter

That's unfortunate. As far as I know, the PEN F is unique in being able to do that.I shoot objects in liquid, which can sometimes move in response to vibrations from the shutter or mirror. It is not a huge problem but sometimes it is hard to anchor my subjects adequately.

I have never observed banding of any kind in either the PEN F or the EM5 MII, even though I often use continuous LED lights run on mains current.

[rjlittlefield]

Something I noticed with the Silent shutter. One issue with that shutter setting is when using mains powered lights with certain exposure settings, you get light and dark bands across the image.

Is this really unique to the silent shutter? And what sort of "mains powered lights" are you using?

The reason I ask is that light/dark bands across the image are often just the result of light intensity varying at 1X or 2X the mains frequency. See for example http://www.photomacrography.net/forum/v ... 193#137193 , panel #3, where I show that a Cree LED screw-in bulb varies more than a standard incandescent, while a Jansjö LED desk light varies not enough to measure.

I suspect that most of us sort of unconsciously avoid settings that will avoid this problem, but I can easily imagine it "suddenly and unexpectedly" cropping up again while running tests focused on shutter performance.

--Rik

[austrokiwi1]

Is this really unique to the silent shutter? And what sort of "mains powered lights" are you using?

I thought I had discussed this some time ago in another thread. It is a well known fault with silent shutter settings. It is related to the frequency of the mains power supply creating , not normally noticeable, flickering. However, the silent shutter setting is actually a video scan. If you have an exposure setting that matches the power frequency (or is complimentary to that frequency) the previously mentioned Flicker caused by the power frequency translates into the light and dark bands on the image. Sony warn users of that particular artifact. I am sure the Oly silent shutter is the same... that the photos on the card don't show it suggests to me, strongly, they have in-camera processing compensating. All I do with the sony is set slow exposures. In day light there is no problem.

Edit: this link shows an better explanation and includes a picture of what I am referring to.

http://www.fredmiranda.com/forum/topic/1382988

[rjlittlefield]

I thought I had discussed this some time ago in another thread.

Could be. I read almost everything here, but I can't remember it all.

However the silent shutter setting is actaully is a video scan.
...
http://www.fredmiranda.com/forum/topic/1382988

Thanks for the link.

Not only is the scan "video", but it's notably slow as well. Quoting from the link you gave,

This total exposure time, even though each line of pixels is exposed for a short time, takes about 1/15th sec or so. Thus for 60 Hz lighting you capture 4 full sinusoidal cycles of variation in the light output as the sensor lines get exposed from top to bottom of the sensor. You can't use silent shutter in this situation.

--Rik

[pteromalus]

Hi, sorry to revive an older thread but I was curious about this:

That said, I am frequently struck that in large part you're struggling with problems that are created by the small size of the sensor.

To take this particular example... Estimating the size of your frame as 50 mm diagonal, then you're running at 0.43X. With a full frame sensor you'd be at 0.86X. Using a nominal f/4 lens in both cases, focused by extension, the effective f-numbers would be 5.72 and 7.44, a ratio of only 1:1.3 in effective f-number versus 1:2 in sensor size, giving an improvement ratio of 1:1.54 in favor of the larger sensor.

If you have to reduce your images to 40 Mp in order to get an image that is sharp at the pixel level, then your Pen F would be handily outdone by a 50 Mp full frame sensor.
--Rik

I follow the logic up up until the improvement ratio part, but what exactly is being improved by 1.54x? Is it that the pixels are up to 2x wider (if both sensors are the same resolution) in the full frame case while the airy disk is only 1.3 times larger, reducing the impact of diffraction? Or is it just the FF's lower noise at minimum ISO?

[rjlittlefield]

Hi, sorry to revive an older thread but I was curious about this:

That said, I am frequently struck that in large part you're struggling with problems that are created by the small size of the sensor.

To take this particular example... Estimating the size of your frame as 50 mm diagonal, then you're running at 0.43X. With a full frame sensor you'd be at 0.86X. Using a nominal f/4 lens in both cases, focused by extension, the effective f-numbers would be 5.72 and 7.44, a ratio of only 1:1.3 in effective f-number versus 1:2 in sensor size, giving an improvement ratio of 1:1.54 in favor of the larger sensor.

If you have to reduce your images to 40 Mp in order to get an image that is sharp at the pixel level, then your Pen F would be handily outdone by a 50 Mp full frame sensor.
--Rik

I follow the logic up up until the improvement ratio part, but what exactly is being improved by 1.54x? Is it that the pixels are up to 2x wider (if both sensors are the same resolution) in the full frame case while the airy disk is only 1.3 times larger, reducing the impact of diffraction? Or is it just the FF's lower noise at minimum ISO?

It's the impact of diffraction.

Perhaps a good intuition can be provided by thinking about the spacing between lens and subject. Suppose you are set up with the f/4 lens and the smaller sensor, working at 0.43X. When you swap in the larger sensor, you need a higher magnification, 0.86X. In order to get that higher magnification, you have to add more extension behind the lens, and then you have to move the lens closer to the subject to maintain focus. Moving the lens closer to the subject gives it a wider entrance cone, and it's that wider entrance cone that reduces the impact of diffraction.

To work the numbers from this intuition, let's compute the effective aperture on the subject side. That number is directly related to resolution on subject.

Using the standard formulas, the subject-side effective f-number = Flens * (1+1/m). Then plugging in m=0.43 and 0.86 gives subject-side effective aperture = f/13.3 for the smaller sensor (micro four-thirds) and f/8.65 for the larger sensor (full frame). The ratio of subject-side effective f-numbers again gives us that factor of improvement, here calculated as 13.3/8.65 = 1.54.

--Rik

[Scarodactyl]

This is kind of assuming a spherical frictionless lens which performs ideally in both configurations. Maybe that's a safe assumption.

[rjlittlefield]

This is kind of assuming a spherical frictionless lens which performs ideally in both configurations. Maybe that's a safe assumption.

It's unlikely that any one lens would perform equally well in both configurations.

But if we get into haggling over lens aberrations, we can postulate aberrations to make the "result" come out however we'd like.

--Rik

[pteromalus]

Perhaps a good intuition can be provided by thinking about the spacing between lens and subject. Suppose you are set up with the f/4 lens and the smaller sensor, working at 0.43X. When you swap in the larger sensor, you need a higher magnification, 0.86X. In order to get that higher magnification, you have to add more extension behind the lens, and then you have to move the lens closer to the subject to maintain focus. Moving the lens closer to the subject gives it a wider entrance cone, and it's that wider entrance cone that reduces the impact of diffraction.

That makes sense, thanks. So the practical impact of this is (potentially) greater detail resolved? But also shallower DOF due to the wider entrance cone? And does this relation still hold if you achieved the equivalent FOV on the FF sensor by swapping in a lens with twice the focal length? Thanks in advance for answering a beginner's questions.

[rjlittlefield]

So the practical impact of this is (potentially) greater detail resolved? But also shallower DOF due to the wider entrance cone?

Yes to both. Diffraction imposes an unavoidable tradeoff between resolution and depth of field. To get high resolution you need a wide entrance cone, but the wider the cone the shallower the DOF. At same FOV, same pixel count, and same final image size, all size sensors live on the same curve that trades off resolution and depth of field.

And does this relation still hold if you achieved the equivalent FOV on the FF sensor by swapping in a lens with twice the focal length?

Lens focal length does not play the same role with small subjects that it does with large ones. When shooting a landscape with micro four thirds and full frame, you get same FOV by using twice the focal length on full frame. But when shooting a postage stamp, you can get the same FOV with a wide range of focal lengths on both cameras, simply by adjusting the extensions so as to give the appropriate magnifications. The focal lengths don't really matter; at same FOV, the DOF and diffraction blur depend on the angular width of the entrance cone and not whether that cone is long or short.

Thanks in advance for answering a beginner's questions.

You're very welcome. We were all beginners sometime!

--Rik

[pteromalus]

Diffraction imposes an unavoidable tradeoff between resolution and depth of field. To get high resolution you need a wide entrance cone, but the wider the cone the shallower the DOF. At same FOV, same pixel count, and same final image size, all size sensors live on the same curve that trades off resolution and depth of field.

So the advantage of FF sensors is that they by default tend towards the higher-resolution/lower-DOF end of the curve? And you could achieve the same movement along the curve with an MFT sensor by simply opening up the aperture (easier said than done if the FF system is already at f/4 of course).

[rjlittlefield]

So the advantage of FF sensors is that they by default tend towards the higher-resolution/lower-DOF end of the curve?

The way I think of it, the advantage of larger sensors is that they open more possibilities. One of those possibilities is to move farther towards the higher-resolution/lower-DOF end of the curve. Another is to get less pixel noise in a single exposure, if you're willing to collect more light to fill up the pixel wells.

For me, the concept of "default" only kicks in at the level of user choice and lens availability. If somebody just sets ISO 100 and f/11, then for sure full frame will give less noise, more resolution, and less DOF than micro four-thirds. But if they set the full frame to ISO 400 and f/whatever so as to get twice the effective f-number, then the resulting images will be same noise, same resolution, same DOF.

And you could achieve the same movement along the curve with an MFT sensor by simply opening up the aperture.

Yes, subject to physical restrictions that keep you from doing that. The lower the magnification, the tougher it is for a small sensor to compete. Lou's example of astrophotography is one extreme, with big advantage to larger. Near the other extreme is say 100X NA 0.80 where with suitable relay lens either size sensor can easily capture all the detail the objective can offer, and the only remaining advantage to the larger sensor is quieter pixels if you collect enough light.

--Rik

[Lou Jost]

It's been more than six years since I started this thread. I have learned a lot since then, and currently I freely flip back and forth between MFT and full frame cameras, depending on what I am doing. But I do think that some of my points here are still valid.

Pixel-shifting increases resolution and reduces noise to the point where MFT image quality is comparable to, or better than, single FF shots. I think now no one doubts this.

Stacked lenses do indeed lower the NA and we now know that there are many outstanding combinations of such lenses. Robert O'Toole's site closeuphotography,com has created a large database of such combinations, backed up by careful tests. I think no one doubts this now.

Rik questioned why I was so determined to squeeze out as much quality as possible in the MFT system rather than just going with a FF system. Now that I have multiple MFT cameras and multiple FF systems, I can better articulate the advantages of MFT. The main advantage by far is simply the weight and size of the lenses. For field work in rough topography, a set of MFT macro, wide, and tele lenses is much lighter and more compact than the corresponding set of a FF system. In situations where I can handle the weight, though, I prefer the FF system.

For macro work, the high pixel density of the MFT sensor makes it useful for finite microscopy systems and for capturing very small subjects in the field. Things 15mm wide almost fill the frame using the standard 1x macro lenses, while on a FF camera at 1x the same object would only fill less than half the frame.

Full frame systems do much better than MFT systems for low-light photography, as long as portability is not needed. As Rik mentions, the extra quality is not due to the sensor size itself but the much bigger lenses that are designed for FF. For this