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Minolta and Laowa Ultra Wides on A7r3
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PostPosted: Mon May 16, 2022 7:03 am    Post subject: Minolta and Laowa Ultra Wides on A7r3 Reply with quote
These images were prepared for use elsewhere, not for uploading here. But why not?

The full credentials, as printed on the lenses:

Minolta MD VFC Rokkor 12.8 f=24mm

Laowa FE 10-18mm f4.5-5.6 C-Dreamer Ultra Wide Zoom

Both were used at f11 in bright overcast light. (A week shaft of sunlight lit part of the background for the Laowa). Exposure 1/80 or 1/100 second. ISO 250. Hand-held. I used the manual lens focusing aid.

In the top right corners there can be seen a tiny aircraft. I would normally crop it out but the DOF might be of interest here.

The plant is Corynabutilon vitifolia (name recently changed) and it is about 12 feet high. Yes, it is leaning, partly due to the weight of water from recent rain.

The shadow in not mine but of a decorative conifer.

The stereos are crosseye.

Minolta:





Laowa at 18mm:




PostPosted: Mon May 16, 2022 8:12 am    Post subject: Reply with quote
I prefer the colour rendering of the Minolta.

Was this on fixed or auto white-balance?

I wonder how the Laowa would render a dense patch of bluebells, although a lot of that will also be down to the camera used.

EDIT: I just noticed that the lighting conditions were different between the two images; more direct sunlight during the Laowa shot so perhaps an unfair comparison...


PostPosted: Mon May 16, 2022 8:21 am    Post subject: Reply with quote
RokkorDoctor wrote:
I prefer the colour rendering of the Minolta.

Was this on fixed or auto white-balance?

I wonder how the Laowa would render a dense patch of bluebells, although a lot of that will also be down to the camera used.

EDIT: I just noticed that the lighting conditions were different between the two images; more direct sunlight during the Laowa shot so perhaps an unfair comparison...


Fixed WB. I have never understood what "Auto WB" is all about.

The lighting was the same on the flowers, the shaft of sunlight only on the grass. It may have been a little brighter. It was cloudy with occasional cracks for sun through very thin cloud, no blue sky.


PostPosted: Mon May 16, 2022 9:23 am    Post subject: Reply with quote
I've taken another look at the images in PS, adjusting brightness.

The Minolta seems to deliver richer colours.


PostPosted: Mon May 16, 2022 10:32 am    Post subject: Reply with quote
This is a lens I haven't used since purchase. I have just picked it up and saw that the focus was set some way into the convex, which should deepen the focus at the edges, if I understand correctly.


PostPosted: Mon May 16, 2022 1:47 pm    Post subject: Reply with quote
e6filmuser wrote:
RokkorDoctor wrote:
I prefer the colour rendering of the Minolta.

Was this on fixed or auto white-balance?

I wonder how the Laowa would render a dense patch of bluebells, although a lot of that will also be down to the camera used.

EDIT: I just noticed that the lighting conditions were different between the two images; more direct sunlight during the Laowa shot so perhaps an unfair comparison...


Fixed WB. I have never understood what "Auto WB" is all about.


Agreed. I rarely use auto-WB myself. Never understood how auto-WB is supposed to work in theory, a concern backed up by auto-WB almost always getting it wrong in practice Wink

Manual WB where you get the camera to adjust and then lock WB when you have access to a completely neutral grey (or white) reference subject I can understand. But auto-WB I do not understand.


PostPosted: Wed May 18, 2022 5:24 am    Post subject: Reply with quote
This comparison makes no sense at all. Why did you do it? What do you want to show?

A 24mm lens is already significantly different from an 18mm one.

The Laowa is weakest at the long end, ie 18mm. And it is a zoom lens...


PostPosted: Wed May 18, 2022 5:57 am    Post subject: Reply with quote
hasenbein wrote:
This comparison makes no sense at all. Why did you do it? What do you want to show?

A 24mm lens is already significantly different from an 18mm one.

The Laowa is weakest at the long end, ie 18mm. And it is a zoom lens...


It wasn't a comparison and, as I have stated, I didn't do it for here. I just wanted an image of the plant filling an appropriate proportion of the frame. Having the images for another purpose, I thought they might be of some interest here.


PostPosted: Wed May 18, 2022 6:33 pm    Post subject: Reply with quote
RokkorDoctor wrote:
e6filmuser wrote:
RokkorDoctor wrote:
I prefer the colour rendering of the Minolta.

Was this on fixed or auto white-balance?

I wonder how the Laowa would render a dense patch of bluebells, although a lot of that will also be down to the camera used.

EDIT: I just noticed that the lighting conditions were different between the two images; more direct sunlight during the Laowa shot so perhaps an unfair comparison...


Fixed WB. I have never understood what "Auto WB" is all about.


Agreed. I rarely use auto-WB myself. Never understood how auto-WB is supposed to work in theory, a concern backed up by auto-WB almost always getting it wrong in practice Wink

Manual WB where you get the camera to adjust and then lock WB when you have access to a completely neutral grey (or white) reference subject I can understand. But auto-WB I do not understand.


https://www.cambridgeincolour.com/tutorials/white-balance.htm

My Canon 5D Classic for auto white balance chose one of the presets, i.e., Daylight, Cloudy, Shade...My Sony A7RII seems to choose auto white balance according to a more accurate algorithm (I haven't checked -- assuming because Sony seems to get WB values closer to correct most of the time.)

Using RAW makes for simple changing of white balance nearly impossible to get right using jpg, for example.


PostPosted: Wed May 18, 2022 7:22 pm    Post subject: Reply with quote
visualopsins wrote:

Using RAW makes for simple changing of white balance nearly impossible to get right using jpg, for example.


Does this refer to Sony or Canon?

I open my Sony RAW files in Sony Imaging Edge Edit. There is an option to select colour temperature if the camera setting has been incorrect. I save the output as TIFFs.

Last edited by e6filmuser on Thu May 19, 2022 5:57 am; edited 1 time in total


PostPosted: Wed May 18, 2022 7:42 pm    Post subject: Reply with quote
e6filmuser wrote:
visualopsins wrote:

Using RAW makes for simple changing of white balance nearly impossible to get right using jpg, for example.


Does this refer to Sony or Canon?

I open my Sony RAW files in Sony Imaging Edge Edit. There is an option to select colour temperature if the camera setting has been incorrect. I save the output as TIIFs.


https://en.wikipedia.org/wiki/List_of_cameras_supporting_a_raw_format

RAW WB is easily corrected using software. Jpg white balance is not easy to change using software.


PostPosted: Thu May 19, 2022 9:14 am    Post subject: Reply with quote
visualopsins wrote:
RokkorDoctor wrote:
e6filmuser wrote:
RokkorDoctor wrote:
I prefer the colour rendering of the Minolta.

Was this on fixed or auto white-balance?

I wonder how the Laowa would render a dense patch of bluebells, although a lot of that will also be down to the camera used.

EDIT: I just noticed that the lighting conditions were different between the two images; more direct sunlight during the Laowa shot so perhaps an unfair comparison...


Fixed WB. I have never understood what "Auto WB" is all about.


Agreed. I rarely use auto-WB myself. Never understood how auto-WB is supposed to work in theory, a concern backed up by auto-WB almost always getting it wrong in practice Wink

Manual WB where you get the camera to adjust and then lock WB when you have access to a completely neutral grey (or white) reference subject I can understand. But auto-WB I do not understand.


https://www.cambridgeincolour.com/tutorials/white-balance.htm

My Canon 5D Classic for auto white balance chose one of the presets, i.e., Daylight, Cloudy, Shade...My Sony A7RII seems to choose auto white balance according to a more accurate algorithm (I haven't checked -- assuming because Sony seems to get WB values closer to correct most of the time.)

Using RAW makes for simple changing of white balance nearly impossible to get right using jpg, for example.



You may have misunderstood (probably semantics Wink ): I know very well how auto-WB is intended to work in theory, which is exactly why I know that it won't work in practice. (the camera getting it right~ish say 50% of the time at best means IMO that it doesn't work). Therefore I don't understand how it is supposed to work in theory (if that makes sense Wink )

That article points out exactly why auto WB simply cannot work (reliably):

A quote from the article:
<article> wrote:
"Certain subjects create problems for a digital camera's auto white balance — even under normal daylight conditions. One example is if the image already has an overabundance of warmth or coolness due to unique subject matter. The image below illustrates a situation where the subject is predominantly red, and so the camera mistakes this for a color cast induced by a warm light source. The camera then tries to compensate for this so that the average color of the image is closer to neutral, but in doing so it unknowingly creates a bluish color cast on the stones. Some digital cameras are more susceptible to this than others."


Every subject is unique. The camera cannot possibly know what elements in the image are supposed to be "neutral" in real life, or what the "average" colour should be, and then even in real life a "neutral" grey/white never looks like that once the reflected light of a light source of unknown variable colour temperature is taken into account.

Outdoors my best, most consistent results are obtained when shooting under fixed daylight WB balance (even when overcast), and then correcting afterwards as required/desired. Indoors, under the modern mixed GLS/LED/FL lighting conditions no preset WB works well anyway, so I adjust afterwards to get the most desirable / least objectionable result.

Whilst RAW gives more dynamic headroom for adjustments, I have no issues at all with doing WB adjustments on JPEGs either, not sure why people keep saying that?


PostPosted: Thu May 19, 2022 9:27 am    Post subject: Reply with quote
This WB issue reminds me of the film colour correction filters for fluorescent lighting, which came in at least three versions.


PostPosted: Thu May 19, 2022 9:39 am    Post subject: Reply with quote
e6filmuser wrote:
This WB issue reminds me of the film colour correction filters for fluorescent lighting, which came in at least three versions.


Therein lies the problem. Traditionally, WB colour correction was done with reference to the colour balance (an spectral nature) of the light source, but auto WB in modern cameras tries to do the same working off the reflected light of the subject. Apples and oranges really. Unless you solve this dichotomy by use of a neutral grey or white card, which is an (imperfect but practical) way of making the camera look at the colour temperature of the light source also.
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