TZ110 Diffraction Compensation test and Focus Stack

I had not known of in camera Diffraction Compensation before reading the manual. I was keen to give it a test.

There is no "ON" option; only OFF and AUTO so I am not sure if the software was doing its job or not. Pixel peeping reveals minuscule difference.

Two focal lengths: 25mm and 250mm equiv. Hola Pro1 Digital achromatic (I think it's achromatic) +3 diopter used on all. Focus stack using Post Focus and Picolay.

Given the small size of the experiment I do not have conclusive results but from what I have seen so far Diffraction Compensation doesn't seem to give any benefit. This is with the proviso that I do not know if it was in operation or not.

Post Focus on the other hand might be of benefit BUT it is dependent on the angle of view. Too shallow and the focusing increments are too coarse and results in soft bands where the stacking software did not have sufficiently wide in focus sections. Probably of no consequence for most people.

The relevant information is in the top right hand corner.

btwango said:

I had not known of in camera Diffraction Compensation before reading the manual. I was keen to give it a test.

There is no "ON" option; only OFF and AUTO so I am not sure if the software was doing its job or not. Pixel peeping reveals minuscule difference.

Two focal lengths: 25mm and 250mm equiv. Hola Pro1 Digital achromatic (I think it's achromatic) +3 diopter used on all. Focus stack using Post Focus and Picolay.

Given the small size of the experiment I do not have conclusive results but from what I have seen so far Diffraction Compensation doesn't seem to give any benefit. This is with the proviso that I do not know if it was in operation or not.

Click to expand...

Think the difference is rather clear in the images shot at f/8. Guess that "Diffraction Compensation" just means that the camera uses more sharpening (and maybe NR too) when using the smallest apertures.

Diffraction compensation is a feature of the newer Panasonic processing engines, and is found in FZ300 and GX8, perhaps others.

Have you tried comparing 2.8 and 8.0 at full wide angle? Wide angle is where I've seen the most prominent narrow-aperture diffraction effects.

btwango said:

I had not known of in camera Diffraction Compensation before reading the manual. I was keen to give it a test.

There is no "ON" option; only OFF and AUTO so I am not sure if the software was doing its job or not. Pixel peeping reveals minuscule difference.

Two focal lengths: 25mm and 250mm equiv. Hola Pro1 Digital achromatic (I think it's achromatic) +3 diopter used on all. Focus stack using Post Focus and Picolay.

Given the small size of the experiment I do not have conclusive results but from what I have seen so far Diffraction Compensation doesn't seem to give any benefit. This is with the proviso that I do not know if it was in operation or not.

Click to expand...

Looks to me like it was operating as both of the "Auto" photos clearly look sharper than the "Off" photos.

btwango said:

Post Focus on the other hand might be of benefit BUT it is dependent on the angle of view. Too shallow and the focusing increments are too coarse and results in soft bands where the stacking software did not have sufficiently wide in focus sections. Probably of no consequence for most people.

Click to expand...

The intent of Post Focus is not for focus stacking, but rather offering multiple focal points from which to choose the most relevant. So I think it's likely doing its job but, unfortunately, trying to take advantage for focus stacking will see more limited success. Those who desire focus stacking typically also desire full resolution over 8 MP as well, further limiting stacking of Post Focus frames.

Wouldn't it be nice if we could just front-focus and let the camera shoot a focus-stepped burst until we reach the rear and let go of the shutter? Perhaps they'll add focus stacking to the app some day...

kkardster said:

btwango said:

I had not known of in camera Diffraction Compensation before reading the manual. I was keen to give it a test.

There is no "ON" option; only OFF and AUTO so I am not sure if the software was doing its job or not. Pixel peeping reveals minuscule difference.

Two focal lengths: 25mm and 250mm equiv. Hola Pro1 Digital achromatic (I think it's achromatic) +3 diopter used on all. Focus stack using Post Focus and Picolay.

Given the small size of the experiment I do not have conclusive results but from what I have seen so far Diffraction Compensation doesn't seem to give any benefit. This is with the proviso that I do not know if it was in operation or not.

Click to expand...

Looks to me like it was operating as both of the "Auto" photos clearly look sharper than the "Off" photos.

kkardster said:

Post Focus on the other hand might be of benefit BUT it is dependent on the angle of view. Too shallow and the focusing increments are too coarse and results in soft bands where the stacking software did not have sufficiently wide in focus sections. Probably of no consequence for most people.

Click to expand...

The intent of Post Focus is not for focus stacking, but rather offering multiple focal points from which to choose the most relevant. So I think it's likely doing its job but, unfortunately, trying to take advantage for focus stacking will see more limited success. Those who desire focus stacking typically also desire full resolution over 8 MP as well, further limiting stacking of Post Focus frames.

Wouldn't it be nice if we could just front-focus and let the camera shoot a focus-stepped burst until we reach the rear and let go of the shutter? Perhaps they'll add focus stacking to the app some day...

--
Bruce
You learn something new every time you press the shutter

Click to expand...

Hi Bruce,

Thank you for your comments.

I would like to add a qualification to my post.

This was an experiment. That is, the out comes were unknown. I am not suggesting that this travel cam is a replacement for Olympus's (is that correct or should it be "Olympus' "? ) Focus Bracketing. I am actually a little surprised my stack turned out as well as it did. As a travel cam I am somewhat smitten by it at the moment.

All that is missing is the travel.

Regards,

B.

btwango said:

Thank you for your comments.

I would like to add a qualification to my post.

This was an experiment. That is, the out comes were unknown. I am not suggesting that this travel cam is a replacement for Olympus's (is that correct or should it be "Olympus' "? ) Focus Bracketing. I am actually a little surprised my stack turned out as well as it did. As a travel cam I am somewhat smitten by it at the moment.

All that is missing is the travel.

Click to expand...

Understood - good to know what we can and can't do. Glad you like the new camera and hope you get to test it on travel soon!

I was wondering about the “Diffraction Compensation” feature too. I haven’t yet received my TZ100 but I’ve received my TZ80 which also has that feature. As the pixels are smaller (about half the width) on the FZ80 than on the TZ100, the TZ80 is affected more by diffraction at f/8.

I tried the feature today using a printed calendar and with the TZ80 at 50mm EFL. There is a note in the TZ80 manual which says “Noise in the periphery of the picture may stand out with higher ISO sensitivity.” So I tested at 800 ISO to see if there was any effect.

Below are 100% crops comparing Diffraction Compensation Off and Auto, for f/4.1 and f/8. The full sized OOC JPGs can be found in my DPR TZ80 gallery.







Although it’s only slight, there did seem to be a sharpening effect which was visible at 100% and f/8. I couldn’t see any effect at f/4.1, although I assume the added sharpening is applied progressively at each aperture setting as diffraction begins to impact the image, which for the TZ80 would be above about f/5.6.

When I tried some PP on the f/8 JPG taken with DC off, I found that applying some USM as for “haze removal” (local contrast enhancement) seemed to give a fairly similar result to the DC feature. By using RAW a better result should be obtained than by using that JPG only feature.

The TZ80 manual says for Diffraction Compensation “The camera raises the resolution by correcting the blurriness caused by diffraction when the aperture is closed.” I think that could be misleading since the resolution/detail that is lost by diffraction can’t be recovered by processing. Maybe it would be better to say that the apparent IQ of of OOC JPGs may be improved slightly by using the feature.

Ian

--
Ianperegian