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SsuperDdave
Moderator
United States
12790 Posts
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I've discovered that my new camera is highly prone to chroma noise when shooting coins. This is an uninspiring "new feature" of the upgrade from 12MP to 18MP (both Canon Rebels). Research seems to indicate it's sensor-related as opposed to lens-related - I get the same noise with any lens - but I don't know a whole lot about ways to correct for it.
I'm shooting RAW, and can correct it in post (now that I've learned that I *can*  ). However, it's an inconvenience.
The camera shows no such behavior in anything except macro shooting, even when pixel-peeping. Furthermore, the effect is more pronounced when using the Jansjos than when using my halogens to illuminate the coin, leading me to believe that it's a function of the amount of lumens I'm throwing at the shot.
It's a lot more noticeable with silver than with copper, although I'm guessing that's a function of the coin's color rather than lessened noise - the natural color of the copper tends to mask it.
Thoughts, suggestions, knowledge? The best thing about a bicycle is that it uses no gasoline, therefore the chance of fiery death is greatly reduced.
First Catman, then Gary Burke and now Bigg Fredd - there's one heck of a coin club in Heaven.
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Valued Member
United States
347 Posts |
Maybe I'm confusing terms, but isn't this highly dependent on the type of lens you are using also? Do some lenses handle the "noise" better than others? Dust in the lens? coatings? haze? Just questions, as I'm still new at this. :)
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Pillar Of The Community
7718 Posts |
I've noticed this too with using a Jansjo on silver coins, albeit w/ my rinky-dink setup.  The more specular the lighting, the more chroma noise I see. I get the least shooting with CFL bulbs. Does your camera's firmware have a contrast adjustment? I know that if the camera compresses the tonal range, it will enhance chroma noise. ISO setting affects chroma noise too. Edited by DVCollector
01/20/2012 12:30 pm
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Valued Member
United States
347 Posts |
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Moderator
United States
12790 Posts |
That was actually the same link at which I clarified my own understanding, brg5658. Since I'd changed so much of my approach simultaneously, my new lenses were on the initial list of suspects but it seems to boil down to the Canon's sensor.
The best thing about a bicycle is that it uses no gasoline, therefore the chance of fiery death is greatly reduced.
First Catman, then Gary Burke and now Bigg Fredd - there's one heck of a coin club in Heaven.
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Pillar Of The Community
United States
1049 Posts |
Maybe this is the "red and blue sparklies" that folks on a couple other forums complain about when using the Jansjos. Bottom line is the Jansjos have a very narrow radiating angle, especially for the brightest central spot, and tend to blast the sensor with specular reflections off the tiny luster mirrors. I don't actually think this is "noise" but is just a symptom of the sensor, or perhaps the processing algorithm, not able to handle the "sparklies". I found it goes away with varying levels of diffusion...Ray
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Pillar Of The Community
Australia
6585 Posts |
I am just wondering if there is some sort of electrical or magnetic interference close by that is upsetting your camera.
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New Member
United States
44 Posts |
Jumping in here kind of late -- but I'm much more knowledgeable about photography than I am with coins and currency, so I thought I'd help :)
First off -- what shooting mode are you using? Typically, you'll want to shoot full manual.
What is your ISO setting? And lastly, how is lighting? Noise is typically a product of ISO and lighting, so you can usually get rid of the noise by adding more light and lowering your ISO setting.
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Pillar Of The Community
United States
1049 Posts |
SuperDave,
Can you show an example of a shot that has a lot of chroma noise? Since I just get the T2i, I want to figure out how to identify it. Can you see the problem in the recent images I've posted that were taken with the T2i?
Ray
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Valued Member
United States
347 Posts |
Hi Ray and Dave, You probably already both know of this site, but I found this review to very helpful! Chapters 14 and 15 (drop down menu) are interesting comparisons. And, the conclusions page is also reassuring for the T2i. http://www.dpreview.com/reviews/can...d/page14.aspCheers, -Brandon |
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Moderator
United States
14444 Posts |
I kind of wish I had gotten the T2i instead of the T1i when I purchased mine. I know there isn't allot of difference between the two but I got a great deal on the T1i so I went ahead and purchased it at the time. If there are allot of advantages of the T2i I may just sell the T1i and try and find a T2i to replace it with. There has to be something that is better besides a few more MP's and external mic jack because everyone seems to be turning to this camera over all others for some reason. I do not see any differences to mention between the T2i and the T3i so unless I found a t3i at the same price I can find a T2i at, I see no real reason to ever fork out any extra money for that specific model. I have a video camera so I don't really use the camera for video very much so the mic port and the extra resolution of the video portion really wouldn't mean much to me
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Moderator
United States
12790 Posts |
Quote:
Jumping in here kind of late -- but I'm much more knowledgeable about photography than I am with coins and currency, so I thought I'd help :)
First off -- what shooting mode are you using? Typically, you'll want to shoot full manual.
What is your ISO setting? And lastly, how is lighting? Noise is typically a product of ISO and lighting, so you can usually get rid of the noise by adding more light and lowering your ISO setting. Ianp, I'm using a Canon T2i with a bellows-mounted 75mm Rodenstock Apo-Rodagon D duplicating lens. Full manual control, of course, and all shooting is done from a computer tether using Canon's Zoom Browser software:   Aperture is set manually at the lens. Both were shot at a set aperture of f/5.6. Given that I'm magnifying, my effective aperture (Feff = Finf (1 + M)) was roughly f/8 for the Morgan, and f/11.2 for the Dime which was about 1:1 on the sensor. ISO was 400 for the Dime and 100 for the Morgan. Both were shot with two of the Jansjo LED lights which seem to be the Official CCF Lighting Source™ these days. One of the reasons I crammed 16GB of RAM into my processing computer was to run my shoots on RAMdisk. I shoot jpeg + RAW, and use the jpegs as "thumbnails" to decide which RAW shots I'm going to process. At the end of the session, I save all the keepers and when I kill the RAMdisk, everything else automatically goes away. Saves on file management. Occasionally I save the whole session, though, and these are a couple of shots from them. They're 100% crops, the first from the jpeg showing the chroma noise, and the second from the equivalent RAW image, having had the chroma processed out. All were shot with the 75 ARD.     Ray, I find the problem far less pressing with copper; it may be that the actual color tends to mask the effect. So no, your Cent shots don't show much of it - nor do mine. When the Componon-S I mentioned arrives later this week, I'm going to use the Morgan pictured above in a series of experimental shots using all 3 lenses and varying lighting; I've a working theory that more candlepower = less noise.
The best thing about a bicycle is that it uses no gasoline, therefore the chance of fiery death is greatly reduced.
First Catman, then Gary Burke and now Bigg Fredd - there's one heck of a coin club in Heaven.
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Moderator
United States
12790 Posts |
Quote:
I do not see any differences to mention between the T2i and the T3i so unless I found a t3i at the same price I can find a T2i at, I see no real reason to ever fork out any extra money for that specific model. I have a video camera so I don't really use the camera for video very much so the mic port and the extra resolution of the video portion really wouldn't mean much to me
That's truth, Bryan. The T3i has a nice articulating LCD viewer if it's an important feature for you, but from a photographic standpoint it's essentially identical to the T2i, using the same sensor and processor/software. Really not worth the extra cash for our purposes.
The best thing about a bicycle is that it uses no gasoline, therefore the chance of fiery death is greatly reduced.
First Catman, then Gary Burke and now Bigg Fredd - there's one heck of a coin club in Heaven.
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Valued Member
United States
347 Posts |
Dave and Ray, you guys are an amazing wealth of knowledge. I purchased just a couple days ago the T2i body, as a back-up to my Canon 50D. I found a great deal on the body through 42nd Street Photo out of NYC, it was $449 for the brand new body (with software CDs, battery, strap, and charger). I have no affiliation with them, but they are a well respected photography dealer and I felt safer going with them than eBay. I'm excited to get it in hand, and I've been reading the full reviews of the T2i body. It is going to also allow me to take HD video of my nieces and nephews which my 50D doesn't have. |
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Moderator
United States
12790 Posts |
The T2i does some pretty amazing video - it's perfectly capable of professional-level results. Now, at the risk of introducing yet another hardcore distraction in your life, Google up "Magic Lantern" and hack that puppy. The best thing about a bicycle is that it uses no gasoline, therefore the chance of fiery death is greatly reduced.
First Catman, then Gary Burke and now Bigg Fredd - there's one heck of a coin club in Heaven.
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Moderator
United States
14444 Posts |
so in your opinion even though I do not do much video at all I should still sell the T1i and upgrade to the T2i just because if I wanted to do 1080P at 24fps I could? And I have had magiclatern on my camera since about a week after I had it
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Posted 01/20/2012 11:42 am
