Ad
Ad
Ad
Pages: « 1 ... 4 5 [6]   Bottom of Page
Print
Author Topic: PMA round up  (Read 34251 times)
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #100 on: February 16, 2008, 12:25:20 AM »
ReplyReply

Quote
Ray, the next time you're someplace that can rent a MFDB feel free to do so.  Let us know what you find.  While you're at it you can also look into Leica lenses and tell us what the Leica look is all about.  It has only taken people 50 years to come up with some theories on that one.
[a href=\"index.php?act=findpost&pid=175196\"][{POST_SNAPBACK}][/a]

Both Leica and Zeiss have always had a good reputation for producing fine lenses, even when I was a little boy. I don't think it's taken people 50 years to realise that or understand the reasons. It was the Germans during WWII who gave the Japanese a leg up, in the production of lenses.
Logged
woof75
Sr. Member
****
Offline Offline

Posts: 581


« Reply #101 on: February 16, 2008, 07:48:49 AM »
ReplyReply

Ray this test is indicative of what I see all the time as typical of the 2 formats. Do you believe me?
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #102 on: February 16, 2008, 09:31:00 AM »
ReplyReply

Quote
Ray this test is indicative of what I see all the time as typical of the 2 formats. Do you believe me?
[a href=\"index.php?act=findpost&pid=175239\"][{POST_SNAPBACK}][/a]

Woof75,
Instead of asking me if I believe you, you should be asking yourself what it is about those two eyes that makes one of them more appealing than the other.

Having examined both crops, I see nothing but make-up, lighting and perspective differences. In the DB shot, the eye has mascara on the lower lid, the white of the eye is brighter and perhaps most important of all, the pupil has a specral highlight.

There are a few other things that probably contribute to the greater appeal of the DB eye. It's at a slight angle and it's slightly larger within the frame.

None of the above characteristic necessarily have anything to do with format, except, if you have difficulty in seeing what you are shooting then that could be the cause of getting a misplaced highlight in the eye. But I'm sure you know that the 1Ds3 can be used tethered, or if that's too much hassle, can be used in LiveView mode which allows for enlargement of the subject on the camera's LCD screen and very precise manual focussing.

Just to make what I'm saying clearer, I've modified the 35mm shot transferring the specral highlight from one eye to the other and lightened the white of the eye in the 35mm shot. I think you'd agree the 35mm shot now looks better and that a misplaced highlight has nothing to do with camera format.

[attachment=5156:attachment]
Logged
woof75
Sr. Member
****
Offline Offline

Posts: 581


« Reply #103 on: February 16, 2008, 09:45:12 AM »
ReplyReply

Quote
Woof75,
Instead of asking me if I believe you, you should be asking yourself what it is about those two eyes that makes one of them more appealing than the other.

Having examined both crops, I see nothing but make-up, lighting and perspective differences. In the DB shot, the eye has mascara on the lower lid, the white of the eye is brighter and perhaps most important of all, the pupil has a specral highlight.

There are a few other things that probably contribute to the greater appeal of the DB eye. It's at a slight angle and it's slightly larger within the frame.

None of the above characteristic necessarily have anything to do with format, except, if you have difficulty in seeing what you are shooting then that could be the cause of getting a misplaced highlight in the eye. But I'm sure you know that the 1Ds3 can be used tethered, or if that's too much hassle, can be used in LiveView mode which allows for enlargement of the subject on the camera's LCD screen and very precise manual focussing.

Just to make what I'm saying clearer, I've modified the 35mm shot transferring the specral highlight from one eye to the other and lightened the white of the eye in the 35mm shot. I think you'd agree the 35mm shot now looks better and that a misplaced highlight has nothing to do with camera format.

[attachment=5156:attachment]
[a href=\"index.php?act=findpost&pid=175262\"][{POST_SNAPBACK}][/a]
Ray, thanks for correcting my "misplaced highlight".  The 1ds 3 can be used tethered too. Have you even used any of these cameras before? You just aren't seeing it, some people do and some people don't, the only way I can describe it is that the db file has a "thickness" to it, some people call it a 3D type thing. Some people see it and some don't, even with that highlight been put in a different place the difference is still there. Theres nothing else I can say, you see it or you don't.
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #104 on: February 16, 2008, 10:46:20 AM »
ReplyReply

Quote
You just aren't seeing it, some people do and some people don't, the only way I can describe it is that the db file has a "thickness" to it, some people call it a 3D type thing. Some people see it and some don't, even with that highlight been put in a different place the difference is still there. Theres nothing else I can say, you see it or you don't.
[a href=\"index.php?act=findpost&pid=175264\"][{POST_SNAPBACK}][/a]

This is why I brought in the audio analogy. You can probably imagine I used to have many an argument with golden eared audiophiles about the implausibility of anyone really being able to hear the subtle differences between different designs of power amps that had sufficient power to drive the speakers. Such people would swear blind that they could hear such differences. There was no doubt in their mind whatsoever, except when there were no visual clues as to which amplifier was in use. Then they were stuffed.

Such matters can only be resolved by going to a lot of trouble taking shots of identical scenes as I've recommended, then getting a third party who is impartial, and who has good skills in Photoshop, to work on both sets of images with the purpose of getting them looking as close as possible. Ideally, it would be better to make prints of both sets of images then people such as yourself could be invited to choose which were from the DB. Such prints would have to be screened first for any tell-tale signs of aliasing which would be a dead give away.

This is the usual scientific method of settling matters like this. You've just presented a pair of images which have very obvious differences which have nothing to do with format differences. To determine if you really can see this subtle 3D effect, we have to eliminate all other differences. In the final analysis, it might well be the case that aliasing will always have some visible effect which will characterise a difference between the two formats. Choice of subject matter would be very important to eliminate this factor.

There are still quality differences between your two crops after my modification. I see more texture in the skin of the forehead in the DB shot, but not more texture under the eye. This makes me think there is still some difference of either focussing or DoF between the 2 shots, perhaps even aliaising.
Logged
woof75
Sr. Member
****
Offline Offline

Posts: 581


« Reply #105 on: February 16, 2008, 12:19:25 PM »
ReplyReply

Quote
This is why I brought in the audio analogy. You can probably imagine I used to have many an argument with golden eared audiophiles about the implausibility of anyone really being able to hear the subtle differences between different designs of power amps that had sufficient power to drive the speakers. Such people would swear blind that they could hear such differences. There was no doubt in their mind whatsoever, except when there were no visual clues as to which amplifier was in use. Then they were stuffed.

Such matters can only be resolved by going to a lot of trouble taking shots of identical scenes as I've recommended, then getting a third party who is impartial, and who has good skills in Photoshop, to work on both sets of images with the purpose of getting them looking as close as possible. Ideally, it would be better to make prints of both sets of images then people such as yourself could be invited to choose which were from the DB. Such prints would have to be screened first for any tell-tale signs of aliasing which would be a dead give away.

This is the usual scientific method of settling matters like this. You've just presented a pair of images which have very obvious differences which have nothing to do with format differences. To determine if you really can see this subtle 3D effect, we have to eliminate all other differences. In the final analysis, it might well be the case that aliasing will always have some visible effect which will characterise a difference between the two formats. Choice of subject matter would be very important to eliminate this factor.

There are still quality differences between your two crops after my modification. I see more texture in the skin of the forehead in the DB shot, but not more texture under the eye. This makes me think there is still some difference of either focussing or DoF between the 2 shots, perhaps even aliaising.
[a href=\"index.php?act=findpost&pid=175283\"][{POST_SNAPBACK}][/a]
One was shot at F19, the other at F16, the distance to subject was a good 10 feet, DOF is not an issue, where does aliasing come into this? Ray, time and time again your showing yourself to be technically inept.
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #106 on: February 16, 2008, 09:22:18 PM »
ReplyReply

Quote
One was shot at F19, the other at F16, the distance to subject was a good 10 feet, DOF is not an issue, where does aliasing come into this? Ray, time and time again your showing yourself to be technically inept.
[a href=\"index.php?act=findpost&pid=175306\"][{POST_SNAPBACK}][/a]

And time and time again you are failing to explain in what way I am technically inept. Just saying so doesn't make it true.

If the width of these images was matched (the shorter side) using a zoom lens so one could shoot from the same position, the f stops should differ by a factor of 1.5x (36/24).

F16 with 35mm should ideally be f24 with DB. Or f19 with DB should ideally be close to f12-13 with 35mm. There's a hint in these shots that 35mm DoF is slightly shallower (less detail in the forehead) when in fact the f stops used would suggest the reverse should be true, so you probably didn't match FoVs only using FL. I think you probably changed position. Therefore I think it's more likely the focussing in the 2 shots is slightly different and that accounts for the greater forhead detail in the DB shot.

Where does aliasing come in? Haven't you been reading the recent threads on the advantages, disadvantages and problems of not having an AA filter? (I'm assuming the P21 does not have an AA filter. Most DBs don't.) Apparently, aliasing can manifest itself in all sorts of unpredictable ways. It's not just a matter of getting better detail at frequencies close to the Nyquist limit, or artificial detail close to the Nyquist limit. One can get harmonic effects at lower frequencies, well below the Nyquist limit.

Sometimes the effects of aliasing are difficult (perhaps impossible) to remove without destroying real detail, yet some people think that a lack of an AA filter imparts a certain 'crispness' to an image and would prefer that their camera did not have one. Some people have gone to the expense of having the AA filter removed from their 5D and are happy with the results.

When making a pair of prints from the two formats (for the purpose of doing this double blind test), one would try to choose images that had no hint of aliasing artifacts in the DB shot. Got it?
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #107 on: February 17, 2008, 12:33:21 AM »
ReplyReply

I would like to add a bit of personal reflection on the sort of locked arguments that take place in threads such as this. Most of us have invested interests, money committed, wisely or not, livelihoods to be supported.

I feel at times, I have an unfair advantage in these discussions because I can afford to be as completley impartial and objective as my talents allow.

I have no myths I feel compelled to support (that I'm conscious of, at least) and no clients that I feel might be influenced by the grandiose nature of my photographic equipment, although I do admit that many strangers I meet as I walk around with a 5D around my neck seem unduly impressed by the appearance of a camera which is so much more prominent (in your face) than the average P&S that most people carry.

I usually feel a bit unconfortable at expressions of "Wow! That's a real camera, isn't it!" and do my best to downplay their impression with a remark like "It's just an old-fashiond 35mm camera, but digital."

I'd just like to say again, it's not about who's right or wrong but why whoever is right is right. Have you learned something? That's all that matters.
Logged
woof75
Sr. Member
****
Offline Offline

Posts: 581


« Reply #108 on: February 17, 2008, 07:50:53 AM »
ReplyReply

Ray, these are tiny crops, like 5% of a frame, if your shooting a person 3/4 length with with a short telephoto lens your depth of field at F16 is such that if the eyelashes are in focus the forehead is. If you knew what you were looking at and/or had the bravery to admit it, you'd look at my examples and realize that the 2 eyes are different and the difference is the difference of the 2 formats. I've seen it time and time again, are all my 35mm shots lacking depth of field and therefore thats the difference? Unfortunately I'm asking you to take one leap of faith in another person which to your detriment you dont seem to be able to do, yes I could have rigged this test, what I'm telling you though is that this test is what I see all the time when comparing the 2 formats. Do you believe me? Your choice. It should be noted that I could sell my MF equipment and get a 1ds 2  if I wanted too at no loss at all and have far less wrist ache when shooting so I dont know where my vested interest comes in.
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8906


« Reply #109 on: February 17, 2008, 12:01:04 PM »
ReplyReply

Quote
If you knew what you were looking at and/or had the bravery to admit it, you'd look at my examples and realize that the 2 eyes are different and the difference is the difference of the 2 formats.

Woof75,
I'm fully aware that the two eyes are different. Have I not already tried to explain to you that you cannot demonstrate what you are trying to demonstrate by comparing two different subjects?

The subjects must be identical. The lighting must be identical. The DoF must be identical. The perspective must be identical and the focussing must be identical. In addition, the exposures should be correct. The lenses should be good and the cameras should be on a tripod. Have I missed anything?

Only then do we stand a chance of being able to see this elusive phenomenom you keep referring to. All differences, apart from the one we are trying to see, become distractions which only serve to confuse the issue.
Logged
Provokot
Jr. Member
**
Offline Offline

Posts: 57


WWW
« Reply #110 on: March 01, 2008, 09:02:32 AM »
ReplyReply

Hmmmmm. STOP ARGUING!

Putting on my Art Director's hat for a moment, I can tell you what I want as someone who uses, rather than makes photographs, I want to be able, one day soon, to crop into much smaller areas of a photograph and get greater clarity from the portion of the pic than I can now with digital.

This requires 2 things:  Cleverer chips with more pixels. (and better quality per pixel)

Much better lenses than are available in any format at present.

I have little doubt that large sums of R&D budget are being spent on both of these issues by all the significant camera, chip and lens manufacturers.

Now y'all be nice!

Paul
Logged

Rob C
Sr. Member
****
Offline Offline

Posts: 12213


« Reply #111 on: March 03, 2008, 03:28:46 AM »
ReplyReply

Quote
Hmmmmm. STOP ARGUING!

Putting on my Art Director's hat for a moment, I can tell you what I want as someone who uses, rather than makes photographs, I want to be able, one day soon, to crop into much smaller areas of a photograph and get greater clarity from the portion of the pic than I can now with digital.

This requires 2 things:  Cleverer chips with more pixels. (and better quality per pixel)

Much better lenses than are available in any format at present.

I have little doubt that large sums of R&D budget are being spent on both of these issues by all the significant camera, chip and lens manufacturers.

Now y'all be nice!

Paul
[a href=\"index.php?act=findpost&pid=178446\"][{POST_SNAPBACK}][/a]

Well now, isnīt that exactly what all photographers have wanted ever since cameras were available? That it can ever happen is highly improbable.

Rob C
Logged

Provokot
Jr. Member
**
Offline Offline

Posts: 57


WWW
« Reply #112 on: March 04, 2008, 05:00:14 AM »
ReplyReply

Quote
Well now, isnīt that exactly what all photographers have wanted ever since cameras were available? That it can ever happen is highly improbable.

Rob C
[a href=\"index.php?act=findpost&pid=178805\"][{POST_SNAPBACK}][/a]

Ummm.... Improbable? Highly Improbable?  No, possible. Just like the probability of having a terrabyte hard drive on a home PC? Or a digital imaging chip of 3, yes, THREE megapixels?  Such things were pure fantasy just a few years ago.  I have no doubt that lenses and imaging sensors will improve as new methods and materials are brought to the table. Its what we now expect.

I am still of the firm belief that in technology terms we are almost at the point where we can with great pride, claim to have scratched the surface.
Logged

Henry Goh
Sr. Member
****
Offline Offline

Posts: 574


« Reply #113 on: March 04, 2008, 05:29:17 AM »
ReplyReply

Quote
Well now, isnīt that exactly what all photographers have wanted ever since cameras were available? That it can ever happen is highly improbable.

Rob C
[a href=\"index.php?act=findpost&pid=178805\"][{POST_SNAPBACK}][/a]

It has already been done.  Last year 2 researchers showed that they can refocus any image after the fact.  They used a camera that has 14 small lenses mount around the perimeter of a main lens.  They can zoom in and refocus any part of the capture.  There were some videos around too.
Logged
Pages: « 1 ... 4 5 [6]   Top of Page
Print
Jump to:  

Ad
Ad
Ad