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Messages - Axilrod

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1171
EOS Bodies - For Stills / Re: RAW and ISO
« on: January 26, 2012, 09:51:33 AM »
Aargh! Somewhere buried in the posts of the last week or so (I think) was a discussion of RAW files, native ISO, how digital cameras read the data, etc. etc.

Now I can't find it. But, at any rate, it was way more technical than I could follow. I'm wondering if some of the more technically-minded participants might be able to give us non-techies a simplified explanation of what they were talking about and why it matters (if it does indeed matter).

When I go out to take pictures and set my 7D to ISO 400 (hey! I shot Tri-X most of my life) and shoot RAW am I really setting the ISO to 400 or am I making some compromise that I am not aware of. And, should I care?


There ARE some very specific caveats about ISO settings when it comes to Canon that do not apply to other sensors (namely, Sony sensors). Canon uses a base/push/pull approach that can really throw you for a loop. First, the base ISO settings, i.e. 100, 200, 400, 800, etc., are the only true "native" ISO settings with Canon cameras (1D X and possibly future gear excepted, they have likely moved to a different approach now). Intermediate settings, such as 125, 160, 250 320, etc. are either "pushed" or "pulled". High ISO settings can be a complex mosh of a variety of methods to achieve the final result.

Every increase in base ISO setting is going to have an impact on DR, usually about 1 stops worth, but its never quite that cut and dry in the real world. This is because you are amplifying the analog signal beyond the lowest native setting of 100 on a scale that has a hard cutoff once you surpass the maximum limit (i.e. 12 bits of luminosity), where your DR should (theoretically) be at its highest. The lower dynamic range may pose problems with clipped highlights if you are not careful. Technically speaking, this should be true for every camera, not just Canon, simply as a matter of physics.

When it comes to ISO 125, 250, 500, etc. those are all "push" settings. Its the base ISO with a +1/3rd stop of in-camera digital "overexposure". When it comes to ISO 160, 320, 640, etc. those are all "pull" settings. Its the base ISO with a -1/3rd stop of in-camera digital "underexposure". This is why some settings on Canon cameras appear to have higher noise than higher ISO settings (i.e. ISO 500 tends to be a bit noisier than ISO 800), and why some settings appear to have lower or similar noise as lower ISO settings (i.e. ISO 320 can be as clean as ISO 100). When it comes to really high ISO settings, such as ISO 3200 or 6400, the story is even more complicated. You end up with several stops of standard analog amplification to ISO 1600, then one or more additional varieties to increase ISO beyond that...you may end up with some additional but less effective analog amplification as well as some digital boost. This is usually why moving from ISO 1600 to ISO 3200 usually results in a LARGE increase in noise, where as moving from ISO 800 to ISO 1600 or ISO 400 to ISO 800 results in a more reasonable increase in noise.

The information above is based on a great post by Daniel Browning on the Canon Digital Photography Forums: http://photography-on-the.net/forum/showthread.php?t=1081982. You can also see the effects of Canon's (probably flawed) approach to ISO settings in this Vimeo video: http://vimeo.com/10473734. For comparison, the D7000 uses one of Sony's newest sensor designs that seems to do a more consistent job with gradually increasing noise: http://vimeo.com/26211959.

Hopefully, the visual examples will clarify the nitty-gritty technical stuff that you were not able to understand from whatever you were reading before. As for whether it matters, overall, mostly no, but on some level, maybe. Noise and the amounts of it tend to be way overblown most of the time. The more we push resolution, the less meaningful noise becomes. If you double the resolution of a sensor, and pixel peep an image from the previous vs. the one from the second...the second will likely "appear" noisier...however there are twice as many pixels, and the apparent noise of every 2x2 block of pixels from the higher resolution represents a single pixel from the lower resolution sensor. Scale down the larger image to the same size as the smaller, and the noise characteristics will likely be the same. The scaled-down larger image could very likely appear LESS noisy, as downscaling has the effect of absorbing small-scale undesirable artifacts. Print is similar, and in a sense, a certain amount of noise is actually USEFUL in print. Print is often as least three times to as much as ten times as dense as a computer screen. Any amount of noise that may be visible at 100% crop on a computer screen with 72-100dpi is likely to be entirely invisible in print at 300-720ppi. A perfectly smooth gradient will usually posterize (create visible banding) in print, but a bit of noise or film grain will usually eliminate any posterization.

One area where higher ISO settings could matter is dynamic range. Every full stop of ISO increase usually means you lose about a stop of DR. With Canon's approach to ISO, you may also lose an extra 1/3rd stop if you are using a push or pull setting, possibly more if you are shooting above ISO 1600. A lot of stuff we photograph doesn't need huge dynamic range, and for the things that do, such as landscapes, we can usually get away with much longer exposures and lower ISO settings (half the time, a long exposure is required for artistic effect...such as long water exposures.) If you need both maximal dynamic range and high sensitivity, then you very likely ARE making a trade-off, and you should be aware of the consequences, as it may affect your ability to get the shot you want.

I wouldn't worry about normal ISO settings...the noise we see at ISO100-800, and for newer cameras even ISO 1600, is pretty much a non-issue in real-world scenarios. The only time noise can really become a problem is when you have to use a higher setting like ISO 1600, 3200, maybe even 6400...and you simply don't have enough available light to really get a full exposure. (I have this problem a lot as I shoot wildlife like elk and deer, and birds, and they usually come out to feed right as the sun sets. The very dim light usually means I have to use ISO 3200 or even 6400, and am unable to fully expose the sensor at the shutter rates necessary to capture the action. You can have the same problem indoors with lenses with small maximum apertures, such as f/5.6.) Noise can become a real problem at that point, and it doesn't really matter what camera brand you use. There are solutions to those problems to, though. You can use flash to produce more light, find ways to increase the available lighting, find ways to reduce the necessary shutter speed (i.e. IS/VR lenses), etc. Dynamic range can really suffer at higher ISO settings, especially if you available light and shutter speed requirements are limiting your ability to fully expose and maximize the use of the sensors available DR.

I have no idea what Mr. Wizard is talking about and no way I'm reading something that long on a message board, but for shooting video use ISOs that are multiples of 160.  I've stuck with throughout all my shoots and the results are definitely better.  This is well known so someone may have mentioned it, but I think it goes against what this guy is saying.

1172
EOS Bodies / Re: 7D Mk2 ..... APS-H
« on: January 26, 2012, 09:45:19 AM »
im just thinking here....

canon said it will not abandon the APS-H sensor format.

would it make sense for canon to put an APS-H sensor in the 7D MK2?

why or why not? what do you think?

i think what speaks against it is EF-S lenses....
but on the other side it would be a nice seperation from the XXD models.

the 70D could have better AF, better body construction etc. and the 7D MK2 would still have some edge.

This makes no sense, the 7D has one of the best autofocus systems out of any Canon camera right now, and the 60D AF is definitely inferior.  You're saying that in one generation that the 7D will improve the AF barely any and the 70D will somehow catch up and pass the 7D?

And if the 70D had better AF and better body construction, how would a 7DII with APS-H have an edge over it?  If you're a wildlife/sports photographer it's not an edge at all.  It just doesn't make sense, right now 7D > 60D, so if they both get upgraded 7DII > 70D.

1173
EOS Bodies / Re: 7D Mk2 ..... APS-H
« on: January 26, 2012, 09:41:24 AM »
the 1D line had two different sensor formats.

maybe they could call it 7Ds. ;)
The 1D line is the top of the line and any camera that Canon wants to list as Flagship will get that number. Anyone who knows enough about cameras to buy anything in that line will know what he or she is getting. Anything that isn't a flagship will be differentiated so as to avoid confusion. There is absolutely no reason to confuse people by changing the sensor in an existing line. It makes no sense from a marketing perspective.

Agreed 100%.  Plus there is already a 7DSV (http://www.photographybay.com/2010/08/17/canon-eos-7dsv-studio-version-announced/), which would make it incredibly confusing. 

1174
EOS Bodies / Re: 7D Mk2 ..... APS-H
« on: January 26, 2012, 09:39:36 AM »
the 1D line had two different sensor formats.

maybe they could call it 7Ds. ;)

Well considering they just merged the 1-series cameras it doesn't seem likely that they would branch out the 7D.

1175
EOS Bodies / Re: 5D3/X and Other Random News
« on: January 25, 2012, 06:03:35 PM »
I really do hope this new body gets announced on February 7th!
 ???

Where is this date coming from?  Seen it several times but can't figure it out, is that the anniversary or whatever?

1176
Lenses / Re: What lenses should I get for my 7d? (16 year old)
« on: January 25, 2012, 02:55:34 PM »
Back to the actual question at hand, my advice would be to spend less time collecting lenses and more time taking pictures and developing your skill. But since I wouldn't listen to that advice, go with a wider angle for your 7D.  ;)

I would have thought a $300 lens was to the point - and why not a 85? He has a 7d not a landscape special, so faster and closer for sports (which the OP asked for) would be an ideal lens. ??? ??? ???

Closer than the 24-105mm L (or the 55-250mm) that he already has? My reasoning was based on the focal lengths that his current lenses cover. I used my 85mm L on my 60D and I didn't like 135mm equivalent length for portraits - and 135mm does not seem very long for sports. He has 2 lenses that cover normal/short tele range and 24mm is not wide on a crop sensor.  I think he should fill some missing numbers and try a wider lens, like the 10-22mm which his "friend" has for $450 or he can find on ebay well within his price range.

B419mac did say he mainly shoots portraits, and the 85mm f/1.8 is no slouch of a lens, but why not upgrade to the 50mm f/1.4 on a 7D? Or if he really wants to get into sports, which is ideal on a 7D, then why not get the 70-200mm L IS that his friend will sell him?

It all comes down to what you want to shoot. Wide-angle just opens up such a new world, I recommend it. Who's to say he can't use the 10-22mm to capture some massive crowd/arena shots at a sports event? I'd even use a fisheye (R.I.P. 15mm f/2.8)!

It doesn't matter what he needs or wants, as cheap as his friend is supposedly selling those lenses it would be foolish not to buy all of them....if not for use, for resale, at which point he would have a much larger budget to get what he actually needs.

1177
EOS Bodies / Re: 5D Mark III (or other) Followup
« on: January 25, 2012, 01:16:02 PM »
Of course EVERYTHING that Canon is releasing is going to have better dynamic range and lower noise at high ISO, that's just a given and it's a waste of bandwidth to even mention inevitable upgrades such as these.

EVERYTHING?  So...the T3i/600D has better DR and less ISO noise than the T2i/550D...or the 7D or 60D?  Oh wait, they use the same sensor, so those parameters are essentially unchanged.  If Canon uses the 5DII sensor in the 5DIII, then what?  Oh, they can claim lower noise in the marketing effort, attributed to Digic5 and applicable to JPG only.

This thread is about the 5DIII, that's what I was talking about.  The 5DII is almost 4 years old, it would be foolish of Canon not to improve the high ISO performance and dynamic range.  It just seems like those changes are inevitable.  There have been a flood of people on CR in the last week because of these posts, it's annoying going through pages and pages of nonsense.

1178
EOS Bodies / Re: 5D Mark III (or other) Followup
« on: January 25, 2012, 09:48:08 AM »
ATTENTION:  I'm tired of reading through pages and pages of wish lists,  "oh if it has better dynamic range and better high ISO performance I'm getting it."  That's pretty much the stupidest and most obvious thing you could hope for in this camera (or any upcoming camera).  Of course EVERYTHING that Canon is releasing is going to have better dynamic range and lower noise at high ISO, that's just a given and it's a waste of bandwidth to even mention inevitable upgrades such as these.

Like Canon is going to forget to improve the dynamic range and iso performance if you don't mention it here on the boards, they are a multi-billion dollar company people where is the trust?  Some of you guys act like Canon is just a group of retards that don't know what they are doing, they don't need your advice. 

1179
Third Party Manufacturers / Re: Lightfield Cameras - The Next Big Thing?
« on: January 24, 2012, 10:07:11 PM »
Yeah this was posted like a year ago, you can adjust focus on some sample pictures here: https://www.lytro.com/living-pictures/2327

1180
Quote
But please remember that if canon keep on releasing lenses at the rate we want, it will be a lens every year

well some lenses are old and need a replacement.
you know how old some of the canon lenses are?

with todays technology there could be a huge jump in IQ.
just look at the 70-200mm f2.8 IS II or the new 300mm f2.8 IS II lenses.

looking at canons past, a new version every 3-5 years would come as a suprise.

im in fact suprised that there is a rumor about a 70-200mm f4 IS II.
the current model was released in november 2006.

the EF 17-40mm is nearly 10 years old.

the EF 50mm f1.4 is 20 years old i think.

the EF 35mm f1.4 is from 1998.

the EF 300mm f4 IS is from 1997

the EF 24-70mm f/2.8L is from 2002.

the EF 100-400mm f/4.5-5.6L IS is from 1998

and these are lenses i sell a lot more often then 500mm or 600mm lenses.

so to be honest... i think we all have waited long enough.... donĀ“t you think?

Indeed! Let us grab the torches and pitch forks! On a serious note, though, before the Earthquake, Canon was in the process of overhauling its line up, starting with the big whites. Hopefully, they will continue, now that things have settled...

That comment doesn't even make sense.

Makes sense to me....  What part of it don't you get?

1181
Lenses / Re: What lenses should I get for my 7d? (16 year old)
« on: January 24, 2012, 03:19:10 PM »

I would suggest that APS-C owners do care about the IQ of their images and sometimes the only way is through the L route

Well, that was certainly the case for me. I am very demanding as far as image quality goes (if I was going to spend the money on a DSLR, I wanted significantly better quality than my point-and-shoot and I wasn't really getting it with the stock lens). I was never really part of the "L or nothing crowd" but funny thing- 2 years later, only one of my lenses is not L (that's the 17-55 2.8 ) Although I did have the 85 1.8 for a short while before trading it in.

I often have the 85 1.8 on my camera - it is an excellent lens. I also use a lot of L lens too - but I dont consider them bling either.

From last night - 1D4 + 85 1.8 - 1/320, iso 400, f/4.5, two flash off camera+pw

I agree, and you can find them for $300 used all the time.  Aside from the bokeh, my 85L II isn't significantly sharper than the 1.8.  I think the 85L is a better lens for sure, but +$1700 better is certainly up for debate. 

1182
United States / Re: Prime lenses you currently own or on your wishlist.
« on: January 24, 2012, 03:17:34 PM »
hmmm.....
I have:
Canon EF 15mm EF f/2.8 Fisheye
Zeiss 21mm f/2.8 ZE
Sigma 50mm f/1.4
Canon 85mm f/1.2L
Canon 100mm f/2.8L IS Macro

Want:
a new 135mm f/2L w/IS
35mm f/1.4
24mm f/1.4
14mm f/2.8L II
a new 135mm f/2L w/IS would be sweet

Dream:..any of the super new light tele lenses...400mm 2.8L IS etc....

My sharpest lens I think is the 100mm Macro..amazing.
Also...when it comes to sharp...I have a 70-200mm 2.8L IS II..now..gotta say (never thought I would)..that bad boy is like shooting with a prime...A.M.A.Z.I.N.G. lens...not good for bokeh..but damn is it sharp.

It is all great fun..with or without!!!!!!!!

I thought that the 70-200 f/2.8 was beautiful, it seemed like you didn't even have to stop down too much to get very shallow DOF, even at f/8 it looked pretty damn blurry.  Then again I guess compared to the macro it may not be as blurry.

1183
EOS Bodies / Re: The 5D Mark III Megapixel Count? [CR2]
« on: January 24, 2012, 03:14:37 PM »
With the risc for beeing called a gearhead or whatever, I will soon change to Nikon despite I have 580EX, 70-200 1:2,8L WFT and a 40D (I know it will cost a lot).
I have sold my 20D two years ago to buy a new Canon semi-pro camera which must be able to use autofocus while taking video. Sony, Panasonic and Nikon can do it . . . .   Come ON Canon, get a hold of your self.

If Canon want to keep being the leading manufactor of cameras in the world, Canon should make a camera with the following specs (will be between 1Dx and 7D (5D mrk II):

Vari-angle monitor 3" OLED or LCD 1.1 mil. pixels display (good in the sun)(protects the oled glas)
Perhaps FF 18MP from 1Dx
ISO 100-51200
The necessary numbers of DIGIC 5+
Video 1080p mode with 60fps
Build-in Stereo mic
Head phone out
Autofocus at Video and Live View
Facedetection during both Video and still
Interchangeable Focusing Screen, Rule of Thirds known as the Golden Mean or Golden Ratio.
Continuous shooting 8fps
Magnisium alloy body
Water resistant (Weathersealing)
19 AF points with 9 cross over
Both CF and SD slots
Build-in WiFi per-to-per directly to laptop
GPS

No matter the cost, I would buy IT !!! (better than change to Nikon, that would also cost).

Great to see some reasonable people here, I swear if I saw one more post with crazy specs and "all for $2500" at the bottom I was gonna scream.  It's like people expect Canon to make them an awesome camera and want it for a ridiculously low price just so it fits their own personal price range.

 I'd like a Ferrari for $20k, but it's not, so I'd look for cars in my price range...not demand that they sell it to me for that.  Just because something isn't in your price range doesn't mean it's a ripoff, it doesn't mean the company is trying to scam you, it just means that you really like something you can't afford and you should look for the next best thing.

1184
EOS Bodies / Re: *UPDATE* 5D Mark III Sighting?
« on: January 24, 2012, 10:33:48 AM »
Anyone know what those 4 little lights are under the screen to the left?  It's like a cluster of 3 small dots and then a slightly larger oval shaped one...

1185
EOS Bodies / Re: Canon EOS 5D X Speculation
« on: January 24, 2012, 10:30:48 AM »
To summarize the last 25 pages of rumor on this body:


(akiskev's image, nicely done)

Anyone else see those 4 little lights under the screen on the left?  Wonder what those are for...

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