CA reducing action - looks like the A2 is gonna need this!

[David Martin]

There is nothing useful and nothing which will help anyone in your
comments - if you have nothing to contribute a moments notoriety by
making inflanmmatory comments hardly seems worhtwhile

The " the A2 is going to need this!," with an exclamation point no
less, provided nothing useful.

It was simply flamebait for every A2 owner or prospective owner.
And if it wasn't done intentionally, then I apologize for my quick
reaction.

But you would think someone with your posting experience would
know better

I would equally have expected anyone who is trying to introduce themselves to a new group to make very sure that they were not misinterpreting.

The written word is not capable of the same degree of inflexion as the voice, and many of us here are mostly addressing people who are already well-known to them and are friends.

At the very least before coming out with that kind of accusation I would check some of their other posts, and see if that was substantiated.
In any circumstances, whatever your opinion, it is wrong and entirely against

any reasonable way of conducting the forum to start name-calling, when a request for clarification would have done fine.

I suggest we forget it, but would ask you to bear in mind that there is nothing more tiresome than reading fora where paranoia has taken over, with multiple accusations of trolling.

It is usually better to discuss the cameras rather than speculating about motivation,and it is foolish to take offence to an odd comment.
--
Regards,
DaveMart
Please see profile for equipment

 

[David Martin]

Here you go:
http://hem.thalamus.nu/~gvp012191/A2/
Very large files

Still see no CA there ... lots of blown highlights from grossly
overexposed images with the attendant CCD blooming and lens flare.
Any examples of CA with properly exposed images?

cheers!
Rick Stirling
http://clanstirling.net/gallery/

Hmmm...perhaps that is not technically the right term, that's interesting.

I am afraid I am not technically competant to engage in the discussions about the differences betweeen CA, PF etc.

I do agree, though, that this is mainly caused by getting the exposure etc wrong, and I have suggested that people try using -2 on the contrast when they have a high-contrast scene, and meter off of a different area or dial in minus values in the EV.

In practical terms though, since it is far better to keep the ISO as low as possible in these 8MP cameras, a lot of people fall foul of probleems when there are tree branches against the sky or whatever since they are shooting with wide apertures.

The action Shay has created seems to do a fine job of correcting it, though, whaever it may be called!
--
Regards,
DaveMart
Please see profile for equipment

 

[Mikhai]

Thanks Dave, the action is helpful. But mine is blue, the problem is not fully corrected. Is there anything I can do except buying the version 5?

 

[William R Stirling]

Hmmm...perhaps that is not technically the right term, that's
interesting.
I am afraid I am not technically competant to engage in the
discussions about the differences betweeen CA, PF etc.
I do agree, though, that this is mainly caused by getting the
exposure etc wrong, and I have suggested that people try using -2
on the contrast when they have a high-contrast scene, and meter off
of a different area or dial in minus values in the EV.
In practical terms though, since it is far better to keep the ISO
as low as possible in these 8MP cameras, a lot of people fall foul
of probleems when there are tree branches against the sky or
whatever since they are shooting with wide apertures.
The action Shay has created seems to do a fine job of correcting
it, though, whaever it may be called!
--
Regards,
DaveMart
Please see profile for equipment

Dave,

I think in the examples you gave here that the blooming and lens flare would have been minimized if not eliminated with an appropriate f/stop and proper exposure. Any time you blow the highlights in digital imaging you run the risk of CCD blooming (an overflow of electrons from a full ccd cell to it's neighbors) The action you posted can help reclaim an image with these effects.

Technical stuff ... The Minolta lens on the A2 and A1 is an APO design - APO means Apochromatic. By definition apochromatic lenses have minimal if any chromatic aberation. Achromatic lens systems ( by far the most common in the digital camera industry) will have chromatic aberation and typically will fail to bring violet into the same focus as red and green. The A1 and A2 lenses are currenty most probably the best there is in a prosumer fixed lens camera.

--
cheers!
Rick Stirling
http://clanstirling.net/gallery/

 

[David Martin]

Hmmm...perhaps that is not technically the right term, that's
interesting.
I am afraid I am not technically competant to engage in the
discussions about the differences betweeen CA, PF etc.
I do agree, though, that this is mainly caused by getting the
exposure etc wrong, and I have suggested that people try using -2
on the contrast when they have a high-contrast scene, and meter off
of a different area or dial in minus values in the EV.
In practical terms though, since it is far better to keep the ISO
as low as possible in these 8MP cameras, a lot of people fall foul
of probleems when there are tree branches against the sky or
whatever since they are shooting with wide apertures.
The action Shay has created seems to do a fine job of correcting
it, though, whaever it may be called!
--
Regards,
DaveMart
Please see profile for equipment

Dave,

I think in the examples you gave here that the blooming and lens
flare would have been minimized if not eliminated with an
appropriate f/stop and proper exposure. Any time you blow the
highlights in digital imaging you run the risk of CCD blooming (an
overflow of electrons from a full ccd cell to it's neighbors) The
action you posted can help reclaim an image with these effects.

Technical stuff ... The Minolta lens on the A2 and A1 is an APO
design - APO means Apochromatic. By definition apochromatic lenses
have minimal if any chromatic aberation. Achromatic lens systems (
by far the most common in the digital camera industry) will have
chromatic aberation and typically will fail to bring violet into
the same focus as red and green. The A1 and A2 lenses are currenty
most probably the best there is in a prosumer fixed lens camera.

--
cheers!
Rick Stirling
http://clanstirling.net/gallery/

Yeah, that was roughly where I was coming from - it's just that some of the discussions when this issue arose over at the Sony forum about transverse CA etc got a bit theological - I was surprised to see anything on the Minolta shots, as I can remember very few problems on my old D7, and I thought the apochromatic lens would be fine.

i don't know whether this is strictly CA, as I didn't get around to checking for matching magenta or green fringes, but the problem with these 8MP cameras seems to be that you have little latitude to underexpose a bit to safeguard the highlights, as noise rapidly becomes apparent if you push the shadows at all.

One of the big advantages the A2 will have over the Sony is a much more usable RAW mode, so that you can push the shadows a bit more.

I have no doubt that good photographers will do fine, but can see newer users getting into trouble.

BTW, did you try Shay's action? I reckon it does a great job, and I've got it in my own actions palette
--
Regards,
DaveMart
Please see profile for equipment

 

[David Martin]

Thanks Dave, the action is helpful. But mine is blue, the problem
is not fully corrected. Is there anything I can do except buying
the version 5?

If you go to the action palette, click the arrow to the right, then click against where it says button mode to turn that mode off.
You will then be able to expand the action, and see what it is doing.
Print that off, or whatever, and run through the action manually.

Whenyou come to the bit where it says 'set foreground colour' and 'Colour range' - fool around with the settings there and you should be able to get it to affect any colour - if you get stuck Shay is a really good guy, and they are very helpful on the retouching forum.
Then make an action of your own to suit.
--
Regards,
DaveMart
Please see profile for equipment

 

[bill hansen]

Dave - I'm relieved to see that you didn't take "fotog" seriously. His post was completely out of line. Your posts to this group have been very helpful to me, and I'm sure to others as well. Keep visiting, keep sharing your experience. I haven't had enough trouble with CA to merit downloading the Shays action yet, but I've bookmarked the site so I can get it, if I do move "up"(?) to the A2 and find that I have CA at that point. Thanks very much for posting this. And as the ancient Romans used to say "Illigitmi non corborundum", or "don't let the [bad guys] grind you down". - Bill Hansen

 

[David Martin]

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

Thanks Bill!
--
Regards,
DaveMart
Please see profile for equipment

 

[David Martin]

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

Bill, I just thought, those PS actions really take up very little space, and they aren't always there when you want them, so I always download anything which looks useful and save it, without neccessarily loading them into PS.

You can often pinch bits of them anyway, file off the serial nubers and use them for something else you want to do
--
Regards,
DaveMart
Please see profile for equipment

 

[Nator]

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

I agree with Bill. I apriciate your help and hope some day that I can render similar assistance to others

 

[David Martin]

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

I agree with Bill. I apriciate your help and hope some day that I
can render similar assistance to others

Thanks guys - ain't the internet a marvellous thing, all the people living thousands of miles away that we would never have known in a previous time? And the chance to form friendshiips without regard for distance?
--
Regards,
DaveMart
Please see profile for equipment

 

[AlanF]

Sure wish someone would point me to an A2 image with CA. I haven't
been able to find one yet.

Here are a couple of crops from Kent Ollson's first picture:
Top left:
http://www.pharphoto.com/irca/a2_kent_olsson_1_crop_tl.bmp

Top right:
http://www.pharphoto.com/irca/a2_kent_olsson_1_crop_tr.bmp

I'm trying to decide whether to go for an A1 at rock-bottom prices,
($499 -$586 + shipping) or an A2 -- best I've seen is $919 + $15 shipping.

To me, the image quality isn't that much better than an A1.
Is the better EVF and movie mode worth it?

The USB2 isn't a big deal either .. I prefer to put my memory card
directly into a dedicated reader.

 

[David Martin]

Thanks Dave, the action is helpful. But mine is blue, the problem
is not fully corrected. Is there anything I can do except buying
the version 5?

Here's an action which will allow you to take out any colour you fancy:
http://forums.dpreview.com/forums/read.asp?forum=1010&message=7721361
Hope this helps
--
Regards,
DaveMart
Please see profile for equipment

 

[Tony SD]

Hmmm...perhaps that is not technically the right term, that's
interesting.
I am afraid I am not technically competant to engage in the
discussions about the differences betweeen CA, PF etc.
I do agree, though, that this is mainly caused by getting the
exposure etc wrong, and I have suggested that people try using -2
on the contrast when they have a high-contrast scene, and meter off
of a different area or dial in minus values in the EV.
In practical terms though, since it is far better to keep the ISO
as low as possible in these 8MP cameras, a lot of people fall foul
of probleems when there are tree branches against the sky or
whatever since they are shooting with wide apertures.
The action Shay has created seems to do a fine job of correcting
it, though, whaever it may be called!
--
Regards,
DaveMart
Please see profile for equipment

Dave,

I think in the examples you gave here that the blooming and lens
flare would have been minimized if not eliminated with an
appropriate f/stop and proper exposure. Any time you blow the
highlights in digital imaging you run the risk of CCD blooming (an
overflow of electrons from a full ccd cell to it's neighbors) The
action you posted can help reclaim an image with these effects.

Technical stuff ... The Minolta lens on the A2 and A1 is an APO
design - APO means Apochromatic. By definition apochromatic lenses
have minimal if any chromatic aberation. Achromatic lens systems (
by far the most common in the digital camera industry) will have
chromatic aberation and typically will fail to bring violet into
the same focus as red and green. The A1 and A2 lenses are currenty
most probably the best there is in a prosumer fixed lens camera.

--
cheers!
Rick Stirling
http://clanstirling.net/gallery/

Err... hang on... Unless my 30+ years as a photomicographer have been wasted:

Red and BLUE are at the opposite ends of the visible spectrum, and achromatic lenses correct for these two extremes. Poorly corrected lenses will show blue fringing one side of an image, and red the other. Good achros correct well for both these wavelengths, but leave a small out of correction element for green in the middle (550nm) Apos then correct for this middle frequency.

I didn't think it was anything to do with violet - but hey! it's years since I've done any of this so I may well be wrong!
--
TonySD

 

[Jonathan Reed]

Dave, many time I've wanted to reply to a particular post of your's, or one that you've helped on. Mainly just to say "thanks". This looks like the time. It's shame when some "person" drags down a helpful thread, or tries to. Just know that your experience and posts are very highly regarded here, by this woefully unperfected(but trying!) A1 user. Thanks Dave from all of us.

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

I agree with Bill. I apriciate your help and hope some day that I
can render similar assistance to others

Thanks guys - ain't the internet a marvellous thing, all the people
living thousands of miles away that we would never have known in a
previous time? And the chance to form friendshiips without regard
for distance?
--
Regards,
DaveMart
Please see profile for equipment

 

[David Martin]

Dave - I'm relieved to see that you didn't take "fotog" seriously.
His post was completely out of line. Your posts to this group have
been very helpful to me, and I'm sure to others as well. Keep
visiting, keep sharing your experience. I haven't had enough
trouble with CA to merit downloading the Shays action yet, but I've
bookmarked the site so I can get it, if I do move "up"(?) to the A2
and find that I have CA at that point. Thanks very much for posting
this. And as the ancient Romans used to say "Illigitmi non
corborundum", or "don't let the [bad guys] grind you down". - Bill
Hansen

I agree with Bill. I apriciate your help and hope some day that I
can render similar assistance to others

Thanks guys - ain't the internet a marvellous thing, all the people
living thousands of miles away that we would never have known in a
previous time? And the chance to form friendshiips without regard
for distance?
--
Regards,
DaveMart
Please see profile for equipment

What can I say? Thank you all, and this thread explains why I was reluctant to buy a Canon camera, and why I hang around here - I don't suppose anyone can get me a Konica-Minolta thingy to stick on my camera?(G)
--
Regards,
DaveMart
Please see profile for equipment

 

[Jim Angelo]

What can I say? Thank you all, and this thread explains why I was
reluctant to buy a Canon camera, and why I hang around here - I
don't suppose anyone can get me a Konica-Minolta thingy to stick on
my camera?(G)
--
Regards,
DaveMart
Please see profile for equipment

Hey Dave, when I get my next edition (maybe an A2) I'll break the Konica part off of the nameplate and send it to you. You can then be the proud owner of a "one of a kind" Konica-Canon. Waddaya think?

Good to see you on the forum.
Jim

 

[David Martin]

What can I say? Thank you all, and this thread explains why I was
reluctant to buy a Canon camera, and why I hang around here - I
don't suppose anyone can get me a Konica-Minolta thingy to stick on
my camera?(G)
--
Regards,
DaveMart
Please see profile for equipment

Hey Dave, when I get my next edition (maybe an A2) I'll break the
Konica part off of the nameplate and send it to you. You can then
be the proud owner of a "one of a kind" Konica-Canon. Waddaya
think?

Good to see you on the forum.
Jim

I want to get the Minolta bit- you have the Konica!
Good to see you too, Jim!
--
Regards,
DaveMart
Please see profile for equipment

 

[William R Stirling]

Err... hang on... Unless my 30+ years as a photomicographer have
been wasted:

Red and BLUE are at the opposite ends of the visible spectrum, and
achromatic lenses correct for these two extremes. Poorly corrected
lenses will show blue fringing one side of an image, and red the
other. Good achros correct well for both these wavelengths, but
leave a small out of correction element for green in the middle
(550nm) Apos then correct for this middle frequency.

I didn't think it was anything to do with violet - but hey! it's
years since I've done any of this so I may well be wrong!
--
TonySD

Glasses of normal dispersion, which have an almost linear decrease in refractive index with increasing wavelength, are used to produce achromat objectives. Only two wavelengths can have the same focus, and the remaining secondary spectrum produces greenish or purple (violet) fringes on images of sharp edges. The higher quality apochromat objectives use glasses having a partial dispersion where the refractive index changes with wavelength more rapidly in either the blue or red region. As a result, apochromats have a high degree of chromatic correction in which up to four wavelengths can have the same image location.

--
cheers!
Rick Stirling
http://clanstirling.net/gallery/

 

[LeifShutter]

I agree. My error. I should have made my point in a more subtle way. In the context of friends, I can now see that your post was not intended to flame. At the same time I think you would agree that there are lots of newbies like myself, some of whom post and many who lurk, and they might not appreciate your subject line if they had just ordered the camera.

I spent quite a bit of time lurking here on several forums, (Fuji, Sony, Minolta) and a trend I have seen too often is to bash the new cameras, and even their prospective users. Sometimes in subtle ways, others more overt. New, enthusiastic faces appear to announce their new purchase. And then they don't post again.

I have ordered an A2, and I can't wait to receive it. Then I will do a head-to-head with my Fuji S7000, and post my conclusions.

I have been involved in photography for over 20 years, from 35 up to 4x5. But I have only a year's experience with digtal. Even so, I hope to be a valuable addition to these forums.

--



Beauty is in the eye of the Bee-holder...