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View Full Version : A700 green color cast...need advice



ILoveTifa
04-30-2008, 12:05 AM
Greetings to everyone in the Sony board :)

I need help with my A700. For some reason, the Auto White Balance almost always produces a green color cast on my pictures. I never used a Minolta before, and this is my first Sony SLR. The store owner assured me that greenish cast is normal on Minoltas, but I guess he lied in order to avoid my complaint. Maybe I just missed some settings?
Any help would be appreciated. Thank you! :D

http://farm3.static.flickr.com/2147/2454109392_a33016fff4_m.jpg
Sony A700 shot, 1/30, F5.6, ISO 200, AWB, @50mm. Notice the green color cast?

http://farm3.static.flickr.com/2002/2453283141_d19456fe12_m.jpg
Nikon D40 shot, 1/30, F5.6, ISO 200, AWB, @50mm.

http://farm3.static.flickr.com/2020/2454110408_ca51be022c_m.jpg
The image, on the LCD. The green is a bit darker.

http://farm4.static.flickr.com/3116/2453283387_2ec4341522_m.jpg

ILoveTifa
04-30-2008, 06:05 AM
Sure, I can avoid using color casts using Custom WB, but what worries me is that the vendor sold me a lemon. I expect A700's AWB to perform better than this. If the product is faulty, then I better hurry to make my claim, but if other A700s do the same thing with their AWB, then I guess I'll have to set the Custom WB every time. What really troubles me is that I bought another Sony compact for my wife (last month), and the sound speaker went bad the following day.

Sorry for the bad English, English is not my native language.

Thank you.

DonSchap
04-30-2008, 06:52 AM
Well ... I can't add much to the color cast in AWB. That appears to be strictly the camera's determination. I know of no menu adjustment to counter this, if there is one available to the user. If you do locate one, please place it in this thread.

As you say ... manually adjusting it out with Custon WB, Color Temperature/Color Filter (page 61 of the manual) or even in the postprocessing is the normal correction for AWB errors ... because it is so ... interpretive.

A simple suggestion: I would compare a "second" A700 with identical conditions and see if it is particular to the cameras line itself, as your store owner seems to indicate. Prove the problem by repeating it. That is much harder to dispute by the manufacturer and can lead to a software fix for everyone.

ILoveTifa
04-30-2008, 08:22 AM
Thanks, DonSchap. Problem is, nobody I know uses A700. It's even very difficult to find accessories for the camera (the store here sells HVL F56AM for roughly U$430) :( , and they don't even have the item in stock.

Don, if you don't mind, would you take a shot of a fluorescent lamp using your A700 on AWB? My A700 always produces a greenish cast whenever I shot a fluorescent lamp using AWB. I'd be interested to hear about your result. (sorry if I'm being impolite Don).

Thank you in advance.

DonSchap
04-30-2008, 08:29 AM
Well ... when I'm in a fluorescent situation, I usually use the supplied fluorescent WB setting. It also has up and down adjustments, just to be sure. AWB is a setting I use rarely ... it comes up in AUTO, but I'm more often in Tungsten lighting ... so I do use that setting as the default.

Makes for a heck of surprise, when I get outside, in Manual, though. LOL What blue I see!

I suppose since I do not use the AWB setting ... I do a lot more work for my shots, but I've gotten kind of use to it. I know it'll be there if I have to do a quick shot and just throw it to AUTO mode -> AWB -> Auto-ISO -> Auto speed -> Auto Aperture -> Autofocus. Just pull the trigger!

I will take your fluorescent shot when I get home, later, and post it.

As far the flash goes: SONY quit offering the HVL-F56AM on the website ... now, it is the HVL-F42AM (they HINT that the "42" is more "atuned" to the SONY DSLRs with this statement:

"Fill the frame with the perfect amount of light using this high-powered flash. Built specifically for your versatile Sony α (alpha) DSLR camera, this flash features wireless functions and a wide illumination range."

which would seem to imply that SONY went ahead and changed the way metering in done under flash in the A700, A200, A300 & A350 from what Minolta had originally designed for the A100, KM-5D & KM-7D).

There is still the older HVL-F36AM (rewrap of the original Minolta-"3600" design) ... and I believe SONY might be bringing a bigger flash to the party for the upcoming "Flagship" release, but I'm guessing on that, based on what they showed at PMA 08.

Personally, I use the "56" ... and it seems to work fine ... but, there are metering distinctions when I use it on the A700. I would have to get a "42" to be absolutely sure of the differences. Nobody, I know of, has addressed this, yet.

SONYNUT
04-30-2008, 10:42 AM
When You Blind The Camera Like That..it's Not Sure What To Doo

ILoveTifa
04-30-2008, 11:47 AM
Thanks a lot Don, I really appreciate it. :)

>Makes for a heck of surprise, when I get outside, in Manual, though. LOL >What blue I see!

LOL! :) Happened to me too. When we were on a wedding, my partner and I switched bodies (he used WA, and I used tele). After I got my camera back, I shot several frames before I realized that he changed my WB. :D

>I suppose since I do not use the AWB setting ... I do a lot more work for my >shots, but I've gotten kind of use to it. I know it'll be there if I have to do a >quick shot and just throw it to AUTO mode -> AWB -> Auto-ISO -> Auto >speed -> Auto Aperture -> Autofocus. Just pull the trigger!

Yeah, I kind of lazy to set my WB when I'm not on the job. It's just that I'm surprised that SONY's AWB cannot handle fluorescent lights well :)
My other cameras AWB deal with fluorescent lighting pretty well (especially my D40) -> I'm not trying to start a war here.

As for the flash, I guess I'll have to wait for a while before settling for a HVL-F42AM, since the competition have some scary names(AF 540 FGZ, 580 EXII, FL 50 R, SB-800!), it's hard to imagine Sony settling for a 'low number' name (42 in this case). Maybe Sony just want avoid being labeled as 'labeling old Minoltas with Sonys', so they scrapped the 56AM altogether?.. (HVL-F56AM = Minolta 5600HS?)

>Personally, I use the "56" ... and it seems to work fine ... but, there are >metering distinctions when I use it on the A700. I would have to get a "42" >to be absolutely sure of the differences. Nobody, I know of, has addressed >this, yet.

You mean, there are exposure differences between your A-100 and A-700 when using the 56AM? I would like to hear it Don.

And SONYNUT, I'm don't really understand what you are trying to say. (I'm a bit slow on this, sorry!) :(

DonSchap
04-30-2008, 01:03 PM
Okay ... you are not nuts ... there is a definite shift to green in using AWB under fluorescent lighting.


AWB . . . . . . . . . . . . . Fluorescent WB +/- 0
3555035551
EXIF: A700 w/ 50mm f/1.4 @ f/2 - 1/90 sec - ISO-200 - AWB/Fluorescent WB


(These are just quick and dirty ... no calculation involved. Just set and fired off.)

I've also noted it in the tri-color histograms with a loss of red in the center range, with the same image taken with "fluorescent WB" vs "AWB." When the red drops out, you get more green, hence the "green cast" in the image.

Is it significant? Like I said, earlier, it can be adjusted out in post processing or accounted for using "fluorescent WB." But, as far as AWB ... it is an A700 issue, as far as I am concerned. You would think they'd be nearly the same. Now, as far as a color match goes, the AWB is a more truer representation than the pinkier "fluorescent WB" shot. Your A700 may just be adjusted strangely. Like I suggested ... get another one, locally, and repeat the test. You really need an identical light source to be sure.

The A100 does not have all these different adjustments ... and I have noted it's AWB may be a little more honest, in that regard. I would have to do a side-by-side ... to truly evaluate it, but as I recall, the A100's AWB was better in coping that way.

And "ILoveTifa", don't worry about starting a good scrap about technical issues on here ... that's how we learn. If no one objected ... well, you would not know to look for these issues. This one is kind of important, since we all run into fluorescent lighting, from time to time ... and need to be aware that in the AUTO mode ... we have a greener world. Personally, I was already compensating for this "green" shift by using the A700's "fluorescent WB" ... which, obviously, does shift it a bit more true than the AWB does.

You could write to SONY and address this issue. Obviously, something like this would be a software fix, in the way they are computing color temperature with the A700. Either AWB was left undercompensating on purpose ... or there just may be a "bad number" in the program for AWB - fluorescent response.

You might want to try your "AWB" vs "Tungsten WB" ... and see if that compensates equally.

I will have to address the nuances of the HVL-56AM on the A100/A700 at another time. As far as I can recall, though, when you place the external flash on the A700, you do not get a corresponding metering indication for use of the flash. The "not enough light" indicators simply go off. It kind of looks like this:



| .
-2 . . -1 . . 0 . . +1 . . +2


You know what ... there's so much to this, I do not want to address it until I'm ready. I apologize for the delay, but it takes time to conduct the analysis and my experiences have been noted and infrequent. Without the other flashes to compare operation, I really don't know what the experience is worth.

I know the discontinued HVL-56AM flash issue was addressed at PMA 08 ... but, I came across no satisfactory or "official" response as to why, that I can share. It's just pure speculation.

EDIT: I compared the A100 in AWB versus Fluorescent WB and there is a significant red shift when using FWB.

So, I would conclude that AWB does not push as hard as FWB into the green elimination. If you consider what a fluorescent filter looks like, if has a powerful pink cast to it. The digital cameras version of that definitely reflects that in the images I am producing from it. You can dial them up or down, but it is a fixed or preset amount, where AWB is on some kind of interpretive sliding scale, based on what it measures to be the actual color temperature.

ILoveTifa
05-01-2008, 06:43 AM
>I've also noted it in the tri-color histograms with a loss of red in the center >range, with the same image taken with "fluorescent WB" vs "AWB." When the >red drops out, you get more green, hence the "green cast" in the image.

In accordance with your post, I did a little Red +15 Green -10 Blue -15 and it did wonders to the picture :).

>Your A700 may just be adjusted strangely. Like I suggested ... get another >one, locally, and repeat the test. You really need an identical light source to be >sure.

Sure Don, thank you so much. I think I'll start pestering the store owner to lend me his other A700 so I can try it a bit, and if my camera is actually a bit off, then maybe I'll have to send it back to Sony for re-calibration. :(

>The A100 does not have all these different adjustments ... and I have noted >it's AWB may be a little more honest, in that regard. I would have to do a >side-by-side ... to truly evaluate it, but as I recall, the A100's AWB was better >in coping that way.

Which makes me wonder, isn't A700 supposed to be a 'more serious' model?

>You know what ... there's so much to this, I do not want to address it until >I'm ready. I apologize for the delay, but it takes time to conduct the analysis >and my experiences have been noted and infrequent. Without the other >flashes to compare operation, I really don't know what the experience is >worth.

Well, anytime you're ready, please share it with us. There's always something new to learn, right?

Thank you so much for your help Don!

ILoveTifa
05-01-2008, 07:19 AM
As a side note, my wife and I went to a local wildlife park near my city. My wife likes taking pictures, but 1. She loves SLR. 2. She hates manual mode. So, I lend her my A700, set it to full auto mode, and.....behold! Green animals!!! :D

http://farm3.static.flickr.com/2362/2457037400_6f2f66716b_m.jpg
http://farm3.static.flickr.com/2026/2456207271_32b82eca5d_m.jpg
http://farm3.static.flickr.com/2244/2456206575_2b9b593ddb_m.jpg
http://farm3.static.flickr.com/2108/2456205955_2e5080502e_m.jpg
http://farm3.static.flickr.com/2247/2456204561_4907bec15a_m.jpg
http://farm3.static.flickr.com/2387/2456204049_00b8a0839e_m.jpg
http://farm4.static.flickr.com/3248/2456203397_1fcbfa39b6_m.jpg
http://farm3.static.flickr.com/2121/2456202673_fc342c5a6d_m.jpg

****gonna get myself a Tamron 18-250 and 70-200 when they become available*** :)

DonSchap
05-01-2008, 08:58 AM
Remember, there are a wide variety of settings (built in filters) for WB on the α700 ... and the performance is much better if you simply learn to set them yourself ... rather than relying on "AWB" to do this adjustment for you. If you are in a hurry, sure ... but, if you are wandering around, outdoors, at the zoo ... set for 5600K or "sunlight." When you move inside ... 3200K or "Tungsten" for incandenscent light. There is a lot to choose from ... but choose!

The "Quik-Nav" menu is a blessing beyond belief. I ask you, how much simpler can it be than to press the "Fn" button, toggle to the particular setting you want to control, press the toggle and make your adjustment? It's not buried under six levels of nonsense, it's right up front ... select your setting and tell it what you want.

35612

Do not be afraid. You will not break the camera. Experiment ... discover ... explore the device. If you get too far out ... reset to the defaults or go right back to AUTO. You effectively have unlimited images (depending on your media), so play and enjoy this wonder of the 21st Century. You are not stuck with the image you get ... change the settings and shoot again! And again! Use the "bracketing" mode ... and get variations automagically in the every same shot.

The α700 camera is capable of so much more than "AUTO" operation ... and believe it or not, that's half the fun and challenge of all the controls. You can, on the fly, change the light. Anyone can grab a camera and trip the shutter ... stuck with whatever built in settings the camera employs. With the α700, you have a whole world of opportunity to choose from.

Personally, when I walk into a undetermined light situation ... I initially use AUTO to get a feel for what the camera is going to initially want for settings. It's just faster, that way. From there (the AUTO settings), I know what I want from the shot, be it action, portrait, landscape, drama, whatever ... the settings are all over the place, but basically revolve around the inital settings that AUTO picked out.

What I am saying is: Use AUTO Mode as a tool, not a selection ... and you will be a lot happier with your results, because then it is you who will have control ... not just some algorithm solution developed in a laboratory.

I will admit that I am occasionally guilty of the same thing: Throwing the camera in AUTO, slapping the external flash on it and handing it off to a novice for shutter operation (this usually happens when I am just too lazy to set up the tripod, get out the "wireless" A700 shutter release and work the shot. Okay, so shoot me. :p I don't get paid by the hour, okay? ).