If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#61
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
Today Stan Birch commented courteously on the subject at hand
Thanks, Paul. What you talk about here is in a group of up to 5 different processing parameters, two are fixed and three I can vary. The settable functions are contrast, sharpness, saturation, color, and something else, but I get the idea. I've ran some very quickie tests varying contrast and sharpness and my images look best at the default for what is called Parameter 1, which is one step more contrasty and one step more sharpness than "neutral". These settings are not all that critical, since the very same adjustments that can be done in the camera can all be done with the post-processing software *IF* you shoot RAW. Dunno what version of Digital Photo Professional came with your camera, but the current (?) version 2.0.3 will cover 95% of your post-processing needs. If you don't have it, download it from the Canon website. Aside from the in-camera parameters DPP allows you to extend those numbers way beyond the the in-camera numbers. I started out using JPGs, since that had worked out very well with my first point and shoot. But after trying shooting RAW, I'd never go back to shooting JPGs. I tend to do at least a little tweaking for anything that's going to be printed; and if you don't want to do a whole lot of fiddling, you can batch-process the entire bunch of photos to JPGs; but most often with paramter changes will be applied on a group by group basis. I rarely use Photoshop for anything any more. Haven't opened the CDs yet, never intend to. If PSP 9 can't do it, I don't want it. There is simply no way, no how, for no reason I will /ever/ shoot in RAW. You like it, I'm happy for you. -- ATM, aka Jerry "I disagree with what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall under the pseudonym Stephen G. Tallentyre |
#62
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
Today Floyd Davidson commented courteously on the subject at
hand Thank you. All Things Mopar wrote: I do /not/, not, not! expect perfect exposures! That just is never gonna happen. What I /hope/ for is /reasonable/ exposures, within +/- 1 f/stop, and /reasonable/ exposure consistency. What If you can get /reasonable/, you can get perfect. First you need to understand the use of your tools and how it applies to the situation at hand though... either the LCD and/or the histogram (yes, Ed, and others, the LCD will show a small histogram, and yes, guys, I at least know enough that what I want is a "mountain" and not a sliver of light at one end or the other). Use the histogram to get close. Then bracket your shots. Your film is cheap, don't conserve it. Iffn my 1st Programmed Auto or full manual exposure is under by more than a stop or 2, I know in advance that color balance will be poor tending toward yellow-red from thee incandescent ambient light, and I know that the background and car shadows will be noisy. So, with flash, I will up the /flash/ EC (or EV if you prefer) by 1, 2, or 3 "EV" - i.e., stops - and take 1, 2, or 3 more shots of the same view. Digital is free, I have plenty of memory and plenty of battery. Exactly. But don't bracket in 1 stop steps, get within 1 fstop and bracketed by 1/3 stop, or whatever you find is close enough to call "perfect". (I'm not familiar with your camera, so I don't know what can be done automatically. You might consider a different camera if yours cannot be set up to fire off a sequence of bracketed shot at the necessary steps. And flash units with battery packs that can recharge fast enough are also obviously needed... if work rate is important.) My goal is typically to get a couple hundred shots in a couple of hours, and separate the really good ones from the OK ones that'll need some work, from the unsavable ones. And, my goal /always/ is to learn from what last worked and what last failed, so that I can apply that new experience next time and improve my ability to use judgment to /predict/ how to set the camera and flash for best possible results. True. But, the relatively trivial points I've made above aside, I don't see any discussion in this article of the fix for your problem. And frankly it seems *obvious* what it is! Go back and read all of that discussion about over and under exposure of variously unevenly light parts of a car. Your problem is not *camera* adjustment, it's inadequate lighting. You need at least one more flash (and maybe two or three would be better). Set it up on a tripod with a remote trigger (either wireless or optical). (I don't know what kind of crowds you have to deal with, but this could end up requiring one or more assistants to hold, or protect, you lights.) That is a start, but just as significant is that these flash units need to be greatly diffused in some way. You've mentioned a virtual lack of walls and ceilings in all locations, so that cannot be part of the solution (and since it would be inconsistent, it would be the least desirable solution anyway). You want to look at diffusion techniques for the flash units. It sounds very much as if two or three flash units mounted on tripods, with something like Stoffen diffusers mounted on them and an umbrella or similar reflecting device, would get predictable and repeatable lighting that is appropriate. -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) -- ATM, aka Jerry "I disagree with what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall under the pseudonym Stephen G. Tallentyre |
#63
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
Chrlz wrote:
Jeremy..just blindly relying on Jeremy auto-exposure. Jeremy Jeremy I think we know by now how seriously to take magazine Jeremy "reviews"... MoparHe wants it, he's gonna get it... Nah, mopar, you don't have an attitude problem. No way. MoparOK, numb nuts, why the hell do you think there is full auto Mopareverything on a Rebel XT? What a nice man...! Call me numb nuts too - HERE'S WHY 'there is full auto everything': - AUTO mode is for when you hand the camera to grandma or grandpa (forgive the stereotype putdown, I'm a grandpa (just) myself!), or to someone who just wants a fair chance of getting a decent picture from an 'easy' scene. - AUTO is also for more professional people, who will use it ONLY in situations where they *know* that the conditions are not going to exceed that particular camera's auto program 'vagaries' or limitations. Every camera is a little different, and it takes your average good-learner, I reckon, anywhere between a week and a few months to get the hang of it. Once that time is up, they will know if it has problems with highlights/backlighting/spotlighting, with its meter's averaging methods, with its flash metering (which is often quite different), and so on. At that time, the *good* camera driver knows when to slip it into manual. Just like a good driver will get the hang of his/her car, and know when to back off, when to turn off the cruise control, when to override the Automatic gear selection .... And every other DSLR... not for me,either. No, nothing ever will be, by the sounds of it. But most of us somehow manage to live reasonably happily within our equipment's somewhat flawed, but (and here's where I *really* differ from you) *highly predictable* behaviour. We still have never seen an example *of the unpredictability* you claim, and if it's predictable and therefore explainable, it's almost certainly solvable. I will continue to maintain that a simple solution is to use manual flash using the old-fashioned guide number method, and it truly isn't difficult. (It sounds as though you simply gave up on that after you did it wrong..) Given a bit of practice, you would almost learn the numbers off by heart after a few shots. And I will continue to maintain that NO automatic exposure system, TTL or otherwise, will reliably handle shiny cars in dark environments, with flash as the main source of light. amateurs who belive (sic) the bull**** that 8+ mega pixels is what they need for 4 x 6 prints Can you post a reference to who says that? I say 5 is *just* enough. Maybe 8 with a bit of cropping.. (O; I /can/ look at the histogram, but why? There's your problem illustrated again right there. It's to tell you when you have under- (or over-) exposed. It also helps identify clipping, but it seems that is not a big problem.. yet. There are myriads of references on the web on how to read/use histograms, eg: http://www.luminous-landscape.com/tu...stograms.shtml That's the first one I found and it's not that bad, even if it doesn't cover cars in museums... I don't display "correct" histograms as wallpaper. And it seems to be clear that you won't ever get properly-exposed images to use as wallpaper either, except perhaps by dumb luck. That 'dumb luck' comment was the only insult contained in this post. Go on, check. Yes, I've been mildly sarcastic and holier-than-thou (as usual), but try arguing the *points* instead of attacking the person. If you can't dispute what I say in a logical fashion, then you lose. And as for this lame 'I won't post examples except on groups' rubbish.. give me a break. I'll happily click on a link, but I'm not wandering off to other binary groups to wade through images there. What a pity: if you were to go to alt.binaries.pictures.autos and look at the thread "Midget racer in speed shop", you'd see the next step, which I expect will explode on this scene very soon. That's it from me, unless we get some meaningful examples posted somewhere reasonable. Horses, water, etc.... |
#64
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
Today Frank ess commented courteously on the subject at hand
Chrlz wrote: Jeremy..just blindly relying on Jeremy auto-exposure. Jeremy Jeremy I think we know by now how seriously to take magazine Jeremy "reviews"... MoparHe wants it, he's gonna get it... Nah, mopar, you don't have an attitude problem. No way. MoparOK, numb nuts, why the hell do you think there is full auto Mopareverything on a Rebel XT? What a nice man...! Call me numb nuts too - HERE'S WHY 'there is full auto everything': - AUTO mode is for when you hand the camera to grandma or grandpa (forgive the stereotype putdown, I'm a grandpa (just) myself!), or to someone who just wants a fair chance of getting a decent picture from an 'easy' scene. - AUTO is also for more professional people, who will use it ONLY in situations where they *know* that the conditions are not going to exceed that particular camera's auto program 'vagaries' or limitations. Every camera is a little different, and it takes your average good-learner, I reckon, anywhere between a week and a few months to get the hang of it. Once that time is up, they will know if it has problems with highlights/backlighting/spotlighting, with its meter's averaging methods, with its flash metering (which is often quite different), and so on. At that time, the *good* camera driver knows when to slip it into manual. Just like a good driver will get the hang of his/her car, and know when to back off, when to turn off the cruise control, when to override the Automatic gear selection .... And every other DSLR... not for me,either. No, nothing ever will be, by the sounds of it. But most of us somehow manage to live reasonably happily within our equipment's somewhat flawed, but (and here's where I *really* differ from you) *highly predictable* behaviour. We still have never seen an example *of the unpredictability* you claim, and if it's predictable and therefore explainable, it's almost certainly solvable. I will continue to maintain that a simple solution is to use manual flash using the old-fashioned guide number method, and it truly isn't difficult. (It sounds as though you simply gave up on that after you did it wrong..) Given a bit of practice, you would almost learn the numbers off by heart after a few shots. And I will continue to maintain that NO automatic exposure system, TTL or otherwise, will reliably handle shiny cars in dark environments, with flash as the main source of light. amateurs who belive (sic) the bull**** that 8+ mega pixels is what they need for 4 x 6 prints Can you post a reference to who says that? I say 5 is *just* enough. Maybe 8 with a bit of cropping.. (O; I /can/ look at the histogram, but why? There's your problem illustrated again right there. It's to tell you when you have under- (or over-) exposed. It also helps identify clipping, but it seems that is not a big problem.. yet. There are myriads of references on the web on how to read/use histograms, eg: http://www.luminous-landscape.com/tu...nderstanding-s eries/understanding-histograms.shtml That's the first one I found and it's not that bad, even if it doesn't cover cars in museums... I don't display "correct" histograms as wallpaper. And it seems to be clear that you won't ever get properly-exposed images to use as wallpaper either, except perhaps by dumb luck. That 'dumb luck' comment was the only insult contained in this post. Go on, check. Yes, I've been mildly sarcastic and holier-than-thou (as usual), but try arguing the *points* instead of attacking the person. If you can't dispute what I say in a logical fashion, then you lose. And as for this lame 'I won't post examples except on groups' rubbish.. give me a break. I'll happily click on a link, but I'm not wandering off to other binary groups to wade through images there. What a pity: if you were to go to alt.binaries.pictures.autos and look at the thread "Midget racer in speed shop", you'd see the next step, which I expect will explode on this scene very soon. That's it from me, unless we get some meaningful examples posted somewhere reasonable. **** Off, Frank Ass! You've contributed no-thing, and I mean NO-THING, in /ANY/ news group you've ever visited except smart-ass crap, like here. Yes, look in Disneyland, asshole, and keep looking, you'll see something when you ain't looking that'll curl the pixels on your monitor. You should stick to your buds in the kooks NG, they're more your speed. -- ATM, aka Jerry "I disagree with what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall under the pseudonym Stephen G. Tallentyre |
#65
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
All Things Mopar wrote:
There is simply no way, no how, for no reason I will /ever/ shoot in RAW. You like it, I'm happy for you. Then why come to a newsgroup like this one and ask for help? If you won't do what works, why pester people with questions? -- Floyd L. Davidson http://www.apaflo.com/floyd_davidson Ukpeagvik (Barrow, Alaska) |
#66
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
Today Floyd Davidson commented courteously on the subject at
hand There is simply no way, no how, for no reason I will /ever/ shoot in RAW. You like it, I'm happy for you. Then why come to a newsgroup like this one and ask for help? If you won't do what works, why pester people with questions? Floyd, please enlighten me and the rest of the world - how does whether I choose to shoot in RAW or not have anything whatsoever with a request for help? What annoys me the most about people like you, is that they are hell bent for leather to show off /their/ knowledge, and not really help people. Again, if you like creating 150MB files, then do whatever floats your boat. Or, just go away until you learn how to play well with the rest of the boys and girls. -- ATM, aka Jerry "I disagree with what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall under the pseudonym Stephen G. Tallentyre |
#67
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
OK well we at least determined your noise isn't all that bad. Noise
looks worse on a monitor than in a print. This was not as bad as noise can be at ISO 1600 on a D70. Yes it was available (sodium? bleck) streetlights, handheld at 1/3 second, Auto white balance & I cooled that down in the raw converted version. I also reduced contrast, applied noise reduction removed sharpening till after & even then used less sharpening, reduced brightness & only a bit on the shadows slider. And the photo was shot at +1EC to overcome the camera meter's reaction to those hot highlights. PS I'm not going to any binaries newsgroup to see pictures, get a web site if you want to share. It probably would be interesting to plenty of car buffs. PPS Oh & I used a wide angle lens to exaggerate the proposterous proportions of that old Caddie. Not a great pic, but relevant to the discussion. All Things Mopar wrote: Today Paul Furman commented courteously on the subject at hand Paul Furman wrote: ATM, check this out: http://www.edgehill.net/1/?SC=go.php...c/photography/ car-iso-1600 Is that similar to what you are getting? Well? I'll post some pics for you if it helps. Paul, I thought I'd replied to you last night. You've been a refreshing voice of reason in a world gone wild with my simple questions and assertions. I did look at this link and it isn't what I see. Similar in many ways, but not the same. Not for you, but fortunately for me, the night scene in this link is far worse than the more minor noise, underexposure bad color balance, and noise. Here's a copy-paste of what I said in reply to you last night: The image in your link, Paul, appears to have been shot available light. I am certainly not criticizing to insult you, but it is soft, looks like it was taken with daylight WB, and is quite noisy. My ISO 800 and 1600 noise, fortunately, isn't this bad. However, if /I/ manage to create and underexposure (it was pointed out to me that it is me, and not the camera's fault grn), then I do get really bad noise. Somebody yesterday said "99% of all noise is caused by underexposure". I would modify that quote this way "Severe underexposure will cause some degree of noise 99% of the time", which isn't at all the same thing. Let me describe a typical shooting situation of a typical car in a typical museum: The car is behind short barriers and there are other cars all around, which limits how far back I can stand and often limits the views of the car I can reasonably get. There is /never/ a low ceiling that I could bounce flash off. There is seldom even one nearby wall for bounce, much less two walls. And, the background is usually more exhibits with the closes wall 20, 30, 50 feet away. In the foreground are typically light colored barriers and one or more signs. Now, by whatever means, suppose I am able to get a "correct" exposure of the car. First, if the I am shooting the car anything other than straight-on, I know that lighting will vary from too bright nearest the camera, somewhere about right in the middle, and took dark/underexposed near the rear of the car, because light from a flash falls off as the /square/ of increased distance. So, it is not uncommon for the fender to be 2 f/stops brighter than the far end of the rear quarter panel. Now, some parts of the car, maybe the fender closes to me, will overexpose and blow out the highlights, there may be flash glare in the door glass, and on the lower parts of the car, shadows may form creating noise in them. And, across a shot taken at a 45 degree angle, lighting will be very uneven. Now, if there's a big sign of some small exhibits in front of the car, they'll be overexposed, sometimes with highlights blown out to white. And, the entire background, what can be seen of the high ceiling, exhibits to the left and right, and the nearest wall behind the car, will all be underexposed by 4-6 f/stops. And, all this dark stuff will be too yellow/red because the high color temp flash pulse doesn't reach that far. So, I strive to expose for the bulk of the key part(s) of the subject, and just let the highlights, shadows, and background do what they will. Available light is a different challenge. However much "inherent" noise anyone wants to believe that a Canon Rebel XT with kit lens will produce at ISO 1600, "correct" exposure /is/ possible, but hardly across the entire scene, including car, foreground, and background. First, ambient light is very low and very uneven. Typically, there are high spot lights shining on parts of the car and other exhibits in the area. Maybe even some fluorescents to mess up the color and maybe some windows to provide our fav problem - backlighting. The overhead spot lights will produce streaks, blobs, and bright oval white spots all over the dark paint of the car. And, the best one can expect to achieve is a relatively even exposure, prefably one stop over, and no more than 1 or 2 stops under throughout the entire scene. Not. I'm going back to the WPC Museum this morning for yet another try with my current treasure trove of new knowledge and give it a go. I'll try "normal" flash issues with my newer Canon 430 EX external flash which has enough range to cover anything in that museum. And, I'll try hand-held available light /with WB set to Tungsteen/ at both ISO 800 and 1600. I do /not/, not, not! expect perfect exposures! That just is never gonna happen. What I /hope/ for is /reasonable/ exposures, within +/- 1 f/stop, and /reasonable/ exposure consistency. What I mean by that last, is if I take 6 shots of one car such as front 3/4, side, rear 3/4, full front, full rear, and a detail shot of the front alloy wheel, I'd like to not have to individually tweak every blinking shot and experiment to get either the LCD and/or the histogram (yes, Ed, and others, the LCD will show a small histogram, and yes, guys, I at least know enough that what I want is a "mountain" and not a sliver of light at one end or the other). Iffn my 1st Programmed Auto or full manual exposure is under by more than a stop or 2, I know in advance that color balance will be poor tending toward yellow-red from thee incandescent ambient light, and I know that the background and car shadows will be noisy. So, with flash, I will up the /flash/ EC (or EV if you prefer) by 1, 2, or 3 "EV" - i.e., stops - and take 1, 2, or 3 more shots of the same view. Digital is free, I have plenty of memory and plenty of battery. My goal is typically to get a couple hundred shots in a couple of hours, and separate the really good ones from the OK ones that'll need some work, from the unsavable ones. And, my goal /always/ is to learn from what last worked and what last failed, so that I can apply that new experience next time and improve my ability to use judgment to /predict/ how to set the camera and flash for best possible results. I will be posting finished pictures from The Henry Ford Musuem and The Walter P. Chrysler Museum to alt.binaries.pictures.autos within a month. You can easily tell which are mine from my All Things Mopar handle. And, if people are truly interested, I can post a /sampling/ of the unedited JPEGs to any NG of choice that I can get with GigaNews. Paul, and others, my belief is that learning is a life-long process, so I never stop trying to improve my techniques for daylight, available light, or flash photography. The reason I recoil against Photog 101 lessons is that while I /understand/ the basics, putting theory into practice in an actual challengin g museum shoot takes more than just RTFM and more than reading magazines and more than looking at other people's successes. So, for you Paul, and for any others who want to approach these issues sanely, rationally, factually, and specifically to my camera and to my peculiar type of museum photography, I would highly encourage continued discussion under a new thread. Perhaps later this week or next week, I'll attempt to start a new thread on one, two, or three particular situations I found myself in, what I tried, what worked and what didn't, and ask for opinions as to how I could have done better. If we /all/ park our egos at the door, things will go well. If we /all/ assume that the other guy is sincere, honest, and reasonably bright, things will go quite well. And, if we stay on-topic and avoid picking spots off the backs of gnats, we'll all get along well, and thus we'll all learn from each other. -- Paul Furman http://www.edgehill.net/1 Bay Natives http://www.baynatives.com |
#68
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
All Things Mopar wrote:
Today Alan Browne commented courteously on the subject at hand Wherever, just say where and put a flag in the subject such as [ATM350] so we can find them. I suggest that you post the photos you were having trouble with as well as the new and improved. OTOH, if you believe you're out of the woods on this issue, don't go to any particular trouble. [We reopen tomorrow, so I'll not have as much time for this...] Alan, anybody who wants to can simply filter me out, do a simple plonk, or just ignore anything with "ATM" on it. It ain't like that is difficult to comprehend and do. No, I don't think I'll post the total crap, the later crap, the almost crap, the new & improved crap, and what I think is OK crap. I bought the camera for /me/, not you. Now, you want to see what it can do? Wait about a month, then take a look at alt.binaries.pictures.autos for my car posts. It should give all you guys major grins to laught silently or out loud on what a flaming, incompetant asshole I really am. So what? I was really interested in the problem you and/or your camera is having. I might even be able to drop a word of advice. I might even learn something. I've done nothing to merit your tone above and I resent it very much. -- -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm -- [SI] gallery & rulz: http://www.pbase.com/shootin -- e-meil: Remove FreeLunch. |
#69
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
|
#70
|
|||
|
|||
More on Canon Rebel XT noise at high ISO - 2 main new data points
On Mon, 02 Jan 2006 23:38:56 -0000, Jeremy Nixon
wrote: wrote: Popular Photography magazine characterized the Rebel XT noise level at 1600 ISO as unacceptable. What did they do; shoot a black frame and then use histogram equalization? They probably shot JPEGs using the LCD review to judge "proper" exposure. Or even just blindly relying on auto-exposure. I think we know by now how seriously to take magazine "reviews"... But honestly, what exactly do you test for when analyzing noise? Most scenes have a wide latitude of colours and illumination levels, some of which will likely show some noise. -Rich |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Using Canon 70-200L F2.8 with X2 Converter | Bill Hilton | 35mm Photo Equipment | 7 | October 24th 05 11:27 PM |
Canon G6 or Digital Rebel or Nikon D70 | NewsBirdie | Digital Photography | 19 | December 31st 04 09:48 PM |
CANON - The Great Innovator (was: CANON – The Great Pretender) | Steven M. Scharf | Digital Photography | 104 | September 3rd 04 01:01 PM |
CANON - The Great Innovator (was: CANON – The Great Pretender) | Steven M. Scharf | 35mm Photo Equipment | 92 | September 3rd 04 01:01 PM |
Canon EOS Digital Rebel - Questions? | John Doe | Digital Photography | 26 | August 26th 04 10:36 PM |