Resolution sharpness and contrast. (2 Viewers)

[Paultricounty]

The use of these terms has come up so many times that I feel they are being misapplied or possibly misinterpreted by us users. When doing a review of an optic here is how I’ve been using the terms.

Resolution, to me means and how Ive been applying it to optics, is how much detail I can see on an object. How many vanes can I see or discern on a wing feather.

Contrast is more a difference in luminance of color difference. An example here for me, I can see more detail , another vane on the feather with SF, but seem to see more coloration difference on each part of that feather better in an Ultravid or Noctivid. Here is where Leica seems dominate to my eyes (always have to add the disclaimer, to me, to my eyes etc. etc.). It’s seems to my small sphere or group, that is a consensus.

Sharpness is how crisp the image is or appears. This can be very subjective but the sharpness in the image will usually add resolution and contrast compared to less sharp Optics. Sharpness can and does help with seeing the small details..
I know there are several methods to test this. The rise distance technique, MTF (modulation transfer function) and some algorithm testing. These tests are above my pay grade in optical knowledge.

It seems that these three terms are being used synonymously and in many ways rightly so, and can confuse a reader of a review. I think part of the reason is that each manufacturer's optical design, coatings and light transmission all play a role in each individuals eye/brain perception. Therefore some people will be able to see a very perceptible resolution difference in Zeiss and others see very little when comparing to a Leica, as the contrast benefit in the Leica makes up in some degree for the better resolution in the Zeiss design.

Paul

 

[Loud Green Man]

Reminds me of a reviewer who described the view through X brand of Alfa bins as having a plasticity-like quality.

Can only think he’d been smoking something other than Old Shag!

LGM

 

[Binastro]

Contrast applies to a black and white photo also..

In astronomy, my eyes are not so good detecting contrast.
I cannot see cloud differences on the planet Venus.
Others can.
Some use filters or just white light.

Regards,
B.

 

[Binastro]

I am certainly no expert in this, but I think that there is colour luminance contrast, of which there are learned papers that come up on a search.

It is suggested that astronomers draw or paint a featureless white egg.
It enables one to learn that the egg is not actually featureless.

Observers vary in detecting faint contrast, faint detail and colour shades.

B.

 

[SeldomPerched]

The use of these terms has come up so many times that I feel they are being misapplied or possibly misinterpreted by us users. When doing a review of an optic here is how I’ve been using the terms.

Resolution, to me means and how Ive been applying it to optics, is how much detail I can see on an object. How many vanes can I see or discern on a wing feather.

Contrast is more a difference in luminance of color difference. An example here for me, I can see more detail , another vane on the feather with SF, but seem to see more coloration difference on each part of that feather better in an Ultravid or Noctivid. Here is where Leica seems dominate to my eyes (always have to add the disclaimer, to me, to my eyes etc. etc.). It’s seems to my small sphere or group, that is a consensus.

Sharpness is how crisp the image is or appears. This can be very subjective but the sharpness in the image will usually add resolution and contrast compared to less sharp Optics. Sharpness can and does help with seeing the small details..
I know there are several methods to test this. The rise distance technique, MTF (modulation transfer function) and some algorithm testing. These tests are above my pay grade in optical knowledge.

It seems that these three terms are being used synonymously and in many ways rightly so, and can confuse a reader of a review. I think part of the reason is that each manufacturer's optical design, coatings and light transmission all play a role in each individuals eye/brain perception. Therefore some people will be able to see a very perceptible resolution difference in Zeiss and others see very little when comparing to a Leica, as the contrast benefit in the Leica makes up in some degree for the better resolution in the Zeiss design.

Paul

Certainly confusing in different people's perceptions. I was in correspondence with a very respected forum member recently and he pointed out — to my eyes rightly — that a Leica 7x42 UVHD Plus was not a particularly high contrast glass. All I can say for sure is what I see as the end product: a beautiful scene if possibly overrich in colour but with sharpness of detail (whatever mixture of resolution and contrast that may entail) slightly reduced compared with some others, especially more modern instruments. Thinking here of Swarovski EL, though of course they are higher mag than 7x and flat field, so those factors muddy the comparison.

 

[Hermann]

The three categories I use are resolution, contrast and transmission. I think they define the "sharpness" of an image in a binocular or scope.

Hermann

 

[SeldomPerched]

Reminds me of a reviewer who described the view through X brand of Alfa bins as having a plasticity-like quality.

Can only think he’d been smoking something other than Old Shag!

LGM

LGM, he may have been using the word in its original sense as used by Leitz in years gone by. I think 'plastic' was taken to mean good modelling or shaping, a 3D effect: one of the effects of their lenses. Think of the 'plastic arts' i.e. arts concerned with modelling, such as sculpture and ceramics.

I just checked this against the Oxford English Dictionary, probably THE authority as far as British English is concerned. (I suspect but don't know for certain that the same meaning can be found in US English too — perhaps a North American forum member can confirm this for us.)

Not to be confused with plastic or waxy skin tones in some digital cameras' output!

Tom

 

[dorubird]

Interesting article about contrast, resolution and more

How to Read MTF Charts

photographylife.com

 

[Vespobuteo]

Resolution is how much detail I can see on an object.

Contrast is more a difference in luminance of color difference.

Sharpness is how crisp the image is or appears. This can be very subjective but the sharpness in the image will usually add resolution and contrast compared to less sharp Optics. Sharpness can and does help with seeing the small details.

Reasonable definitions.

Note that Allbinos is not using these in their reviews..

More than in a relative way in the category "Blurring at the edge of the FOV."

All bins seem to be sharp in the center...

 

[Paultricounty]

Certainly confusing in different people's perceptions. I was in correspondence with a very respected forum member recently and he pointed out — to my eyes rightly — that a Leica 7x42 UVHD Plus was not a particularly high contrast glass. All I can say for sure is what I see as the end product: a beautiful scene if possibly overrich in colour but with sharpness of detail (whatever mixture of resolution and contrast that may entail) slightly reduced compared with some others, especially more modern instruments. Thinking here of Swarovski EL, though of course they are higher mag than 7x and flat field, so those factors muddy the comparison.

I believe , correct me if I’m wrong, Ultravids and EL’s are about the same vintage in time of introduction and each have gone on to make evolutionarily improvements over time. This is a very interesting dichotomy in perception of optics. Desired use and enjoyment are a delicate balance and come into play as to which one is better, more contrast or more resolution, of course when we’re comparing very equal optical quality instruments. A more similar comparison can be had with the Leica 8x32 UVHD+ and the Swaro 8x32EL SV.

Paul

 

[Maljunulo]

“Sharpness” can be created in an image simply with edge enhancement, so in one sense increased sharpness is merely an artifact, if it isn’t there in the first place.

 

[dorubird]

Resolution means separating power and sharpness is a more generic and subjective term similar to clarity for me. I use the term "sharpness" or "clarity" when I want to sum up contrast and resolution together.
For example SF 10x42 and EL 10x42. Both give a general impression of high sharpness (good resolution and contrast), but only in comparison I noticed some difference between them: it can be seen that the sharpness of the EL is mainly given by the contrast and the sharpness of the SF is mainly given by the resolution (power of separate very fine details). So SW EL 10x42 has a higher contrast than the Zeiss SF 10x42, and SF has a higher resolution than the EL, but yet they are comparable in terms of sharpness.

 

[jafritten]

LGM, he may have been using the word in its original sense as used by Leitz in years gone by. I think 'plastic' was taken to mean good modelling or shaping, a 3D effect: one of the effects of their lenses. Think of the 'plastic arts' i.e. arts concerned with modelling, such as sculpture and ceramics.

I just checked this against the Oxford English Dictionary, probably THE authority as far as British English is concerned. (I suspect but don't know for certain that the same meaning can be found in US English too — perhaps a North American forum member can confirm this for us.)

Not to be confused with plastic or waxy skin tones in some digital cameras' output!

Tom

Plasticity is a metaphorical term to describe what some refer to as "3D". The Leica Summicron 35mm or the Pentax FA 43mm are good examples when used at certain distances and f/stops. I think field curvature and slight differences in brightness (less bright towards the field stop, i.e. vignetting) and, possibly, contrast/microcontrast contribute to this effect.

BTW the term is also used with reference to sound. I am sure some musicians or Hifi-enthusiasts will understand "plasticity" this way, too.

 

[Maljunulo]

“Plastic surgery” does not refer to performing surgery on polymers, but to the reshaping involved.

Dogs are said to be “plastic” because they can be so radically changed by selective breeding, whereas cats still look pretty much like just another cat. Hence, cats are not described as plastic.

 

[tenex]

I think the problem here is that "resolution" and "contrast" both have specific technical meanings while "sharpness" does not, instead describing a perception or impression that probably involves both (and perhaps more yet).

"Plasticity" as a metaphor makes sense to me where ductility, reshaping etc are involved, not with respect to "3D" (which I find confusing enough already).

 

[jafritten]

"Plasticity" as a metaphor makes sense to me where ductility, reshaping etc are involved, not with respect to "3D" (which I find confusing enough already).

Maybe the reviewer mentioned by @Loud Green Man was German and "plasticity" is the translation of German "Plastizität" which could be used to describe the very quality of the photo below taken with a Zeiss lens.

 

[Maljunulo]

Maybe the reviewer mentioned by @Loud Green Man was German and "plasticity" is the translation of German "Plastizität" which could be used to describe the very quality of the photo below taken with a Zeiss lens.

Oh, joy!

Yet another definition, and from another language, and from photography, which isn’t what we are doing.

 

[Ted Y.]

Resolution means separating power and sharpness is a more generic and subjective term similar to clarity for me. I use the term "sharpness" or "clarity" when I want to sum up contrast and resolution together.
For example SF 10x42 and EL 10x42. Both give a general impression of high sharpness (good resolution and contrast), but only in comparison I noticed some difference between them: it can be seen that the sharpness of the EL is mainly given by the contrast and the sharpness of the SF is mainly given by the resolution (power of separate very fine details). So SW EL 10x42 has a higher contrast than the Zeiss SF 10x42, and SF has a higher resolution than the EL, but yet they are comparable in terms of sharpness.

No one else tested binoculars with a high contrast and a very good resolution versus very good contrast and high resolution?
I am curious what the people doing photo and also using binoculars think about this.

 

[Maljunulo]

How do we quantify “high contrast” in order to remove it from the realm of the subjective, and who among us is equipped to do so?

 

[Ted Y.]

How do we quantify “high contrast” in order to remove it from the realm of the subjective, and who among us is equipped to do so?

It seems 3 different formulae exist for quantifying the contrast.
Probably one single user is equipped to measure the contrast, the Zeiss member.