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Messages - Stu_bert

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46
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 06, 2014, 02:32:24 AM »
Welcome.

Re A7R - http://www.sansmirror.com/cameras/a-note-about-camera-reviews/sony-nex-camera-reviews/sony-a7-and-a7r-review.html

Scroll down to "How do they Perform?"

I believe that only applies to their 11-bit "RAW" encoding. That would be something akin to Canon's sRAW and mRAW, not necessarily in encoding, but in lossyness. Neither are actually RAW files, they encode data in a specific way. In Canon's case, the m/sRAW formats are YCb'Cr' formats, or Luminance + Chrominance Blue-Yellow + Chrominance Red-Green. The Y or Luminance channels is stored full resolution, however the Cb and Cr channels are stored "sparse". In Canon's case, all of the stored values are still 14-bit precision, but they do store lower chrominance data. Canon's images would be superior to Sony's, in both that they store more information in total, as well as with a greater bit depth...however both will suffer from the same limitation: The information is not actually RAW, which severely limits your editing latitude.

Generally speaking, the fact that these formats store lower resolution color information doesn't matter all that much. Because of the way our brains process information, if done carefully, a lower resolution chrominance is "missed" in favor of a higher level of detail. YCbCr formats have been around for a long time, since the dawn of color TV even. The Luminance channel was extracted and sent in full detail, while the blue/yellow and red/green channels were sent separately, in a more highly compressed format. This actually allowed color information to be piggybacked on the same signal that "black and white" TV channels were sent on, making it possible for B&W TVs to pick up the same signal as Color TVs.

If you have paid any attention to Canon's video features, you've already heard of similar video compression techniques. You may have heard of 4:1:1, 4:2:2, or 4:4:4. Those numbers refer to the Y, Cb, and Cr channel encoding. A 4:1:1 encoding has full luminance and 1/4 Cb & Cr channels. A 4:2:2 encoding has full luminance and 1/2 Cb and Cr channels.  As you might expect, a 4:4:4 encoding use the same sampling rate for all three channels, and is effectively "full resolution". A standard RAW image is also technically a 4:4:4 R'G'B' image.

Jrista - did not appreciate that for mRaw/sRaw so thank you. My understanding on Sony is however, that their 11 bit RAW is their standard raw. I'm not sure if you read the whole article, but Tom is talking about deficiencies as a result, and he's comparing it to the D800. There's a further link embedded

http://www.rawdigger.com/howtouse/sony-craw-arw2-posterization-detection

which I believe confirms that they do the same on all their RAW encoding.

Don't get me wrong, I think many people would not notice it or can work around it - Fred Miranda has been positive in his review and he's a canon user - in fact I think there's a whole forum on his site discussing it in detail. To me it just seems somewhat self-defeating - you have a sensor with better DR than your competitors but you then impair the output with your compression scheme which "fails" when you have scene with higher DR.

Maybe I misinterpreted the information...

47
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 05, 2014, 06:52:15 PM »
Glancing at his gear wish list, it looks like he's more into action than astro. An A7R is 2500 less in the budget (camera + EF adapter). Personally I would love one for portrait and landscape work, but I can not justify the expense. I suspect I'd get more use from that tamron 150-600 and a new tripod.

So, while I'd like an A7r for my landscape photography, it is actually one of the worst possible choices for astrophotography. I do landscapes sometimes, wildlife and birds most of the time, and astrophotography every time there is a clear night.


I was looking at the A7R with adapter for landscapes, but then I read on Thom Hogan's site that Sony uses lossy compression on their RAWs (unless I misread him), and you can't switch it off!

Why would they do that?   :( :(

On that basis, it may have amazing DR but then it surely will just smudge out some of the detail for err, actually I'm not sure for what benefit...

Hmm, I hadn't heard of that. If they do, it's foolish, and you really no longer have a RAW image. I am a bit skeptical of that...it doesn't seem logical, but who knows.

Had a look at that astro link - it's a whole new language there  :) If I understood correctly, then it's a 2000mm lens? And optically is it better than your 600mm lens with a 1.4x and 2.x attached? Just curious as to the benefits. Thanks.

Reflecting light tends to produce superior spots at the sensor plane in comparison to refracting light. Reflecting light can warp star diffraction spots due to coma and astigmatism, but that's about it. Refracting light, on the other hand, suffers from all forms of optical aberrations...which also includes chromatic aberrations, spherical aberration, etc. The RC, or Ritchey-Chretien, telescope design is one of the more superior designs. It's the same design used in all the major earth-bound telescopes...the huge ones, up to 10 meters in size. It tends to produce superior results, although it does suffer from some coma and astigmatism in the corners.

There is a better telescope design than even the RC, called a CDK or Corrected Dall-Kirkham. The CDK uses a mirror and built in corrector to get one of the best spot shapes, center to corner, of any telescope design I've ever seen. PlaneWave makes CDK scopes, but they are pretty pricey. From what I've read and seen, a CDK is about the best telescope design in the world today.

As good as my lens is, and it is very good with a very flat field corner to corner, it is no RC and certainly no CDK. If I throw on teleconverters, that gets me more focal length (which is not necessarily the best thing...a LOT of nebula are even larger than I can fit in my field with the 600mm, let alone a 2000mm scope), but  it also increases the optical aberrations. For galaxies, clusters, and getting close up on parts of nebula, a longer, better scope like the Astro-Tech 10" RC is better. The larger aperture, ten inches vs. six inches, also means I can resolve smaller magnitude stars, galaxies, and other details. Most scopes work with focal reducers, so while it is 2000mm natively, I can use a 0.63x reducer to make it an f/5 1260mm telescope. That is relatively fast with a moderately wide field. For planetary work, I can also throw on a 2x or 3x barlow lens, and get a 400mm f/16 or 6000mm f/24 scope, which is much better for planetary imaging (f-ratio doesn't usually matter for planetary, as you image planets by taking videos with thousands of frames for anywhere from a couple minutes to as long as a half hour...then filter, register, and stack the best frames of the video, which is basically performing a superresolution integration...that eliminates blurring from seeing, and effectively allows you to image well beyond the diffraction limit.)

Thanks for the comprehensive reply.

Re A7R - http://www.sansmirror.com/cameras/a-note-about-camera-reviews/sony-nex-camera-reviews/sony-a7-and-a7r-review.html

Scroll down to "How do they Perform?"

48
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 05, 2014, 06:06:42 AM »
Glancing at his gear wish list, it looks like he's more into action than astro. An A7R is 2500 less in the budget (camera + EF adapter). Personally I would love one for portrait and landscape work, but I can not justify the expense. I suspect I'd get more use from that tamron 150-600 and a new tripod.

So, while I'd like an A7r for my landscape photography, it is actually one of the worst possible choices for astrophotography. I do landscapes sometimes, wildlife and birds most of the time, and astrophotography every time there is a clear night.


I was looking at the A7R with adapter for landscapes, but then I read on Thom Hogan's site that Sony uses lossy compression on their RAWs (unless I misread him), and you can't switch it off!

Why would they do that?   :( :(

On that basis, it may have amazing DR but then it surely will just smudge out some of the detail for err, actually I'm not sure for what benefit...

Had a look at that astro link - it's a whole new language there  :) If I understood correctly, then it's a 2000mm lens? And optically is it better than your 600mm lens with a 1.4x and 2.x attached? Just curious as to the benefits. Thanks.

49
Yesterday we posted an internal service advisory for the Canon EOS-1D X and EOS-1D C. These are advisories that are only known to a select few within Canon and not told to the consumers.

We have a lot of more of these documents that cover various Canon lenses and camera bodies, there’s even more on the EOS-1D X mirrorbox.

The person that sent them to us didn’t have an issue with Canon keeping this stuff internal. However, they were upset that a lot of the issues are known to Canon and they’re still charging customers for the repairs out of warranty. There are a couple of lenses with design flaws and Canon is charging $250-$450 for these repairs out of warranty and not fully disclosing the design flaw to the customer.

We’re not sure whether or not we’ll post the rest of the internal documents we have in our possession. If you think there’s value in us doing so, please sound off in our forum

cr

With the last sentence it sounds like you are blatantly bating people to generate more site traffic and have no intention to post anything. It is also worth noting that since the post, you have not followed up. If you were seeking the possible pro's and con's, then I would have expected you to contribute. You haven't, which again leads me back to the 1st point.

I understand the response from many people who are worried about their investment having a flaw or known issue. Part of me would be similar, especially if I knew the equipment may fail at a decisive moment, even more so when it costs thousands of pounds. The problem, as stated, is that many people would indeed try to pre-empt such a problem and unless the internal documents highlight the % impact, then you cause a storm of requests to Canon for a very small issue.

Frankly, whereas you intentions may have been honourable, this thread comes across as manipulation.

I concur with the conclusion of one of the other posters. Provide the info anonymously to your local authority. Providing it to media I think would just result in further exploitation to increase publicity.

Speak about class action is indeed what would make any website owner be incredibly reticent to publish such information.

Finally, I think what would be helpful is indeed to start a new section about actual faults / repairs by model in this site. People can post their problems, see if others concur it as a fault or corroborate based on their own equipment. That would be a useful outcome IMHO. A thread per equipment with sticky post with stats of fault issues (unsharp glass, back/front focus etc) allows people to see problems, but of course would only be useful if those people who *dont* have the problems also post likewise.

50
Canon General / Re: Travel charger for Canon LP-E4N battery
« on: April 02, 2014, 05:27:52 PM »
I travel on a lot of and have always wondered why Canon did not make a one battery charger (even if only to buy as an accessory). I use more than one battery a day quite frequently, but would be more than happy with a one battery charger if they made one. As it is now, I just travel with the original.

I do agree, and would have purchased one like you if Canon did it as a backup. Any long trip (>1 week) then I always take 2 chargers, so two singles or a single n double would be ideal.

No third party charger is ever going anywhere near my Canon batteries.
Not to challenge, more to understand, but why not? Do you not use 3rd party batteries?

Out of curiosity, has anyone ever opened the brick which Canon supplies? I always got the impression that it's 80% empty inside...

51
Canon General / Re: Travel charger for Canon LP-E4N battery
« on: April 02, 2014, 02:22:51 AM »
i've used an LC-E4 charger from China via ebay which is half the size and works fine for 1Ds batteries, but I've only used occasionally and therefore can't comment on longer term use. Funnily enough, I tend to drag 2 chargers wherever I travel, and the chinese clone is only used when I'm really tight on luggage (but I still take a Canon)

Is the LC-E4N "compatible" with LC-E4 ?

Just search for LC-E4 battery charger if you're interested...

52
PowerShot / Re: Canon EOS Smart 1 Phone
« on: March 31, 2014, 12:58:26 PM »
And not very good photoshop, look at the canon logo on the right hand device, perspective all wrong....  :-[

53
EOS Bodies / Re: 1DX Won't Power On
« on: March 18, 2014, 07:08:37 PM »
Rang, I only use Canon batteries-

Student of the light- I have formatted the cards- I format them when I traqnsfer the photos to the computer

Neuro- one more time- They weren't even going to perform the product advisory work UNTIL I approved of being charged for work that was covered under warranty- I had to fight with them to even perform the product advisory work- they simply had set the camera on a shelf and never even began work on the product advisory issue- they should have at least done that work then contacted me IF they felt there was an issue with the warranty concerning the other issue, and asked me how to continue. They did not- they apparently weren't even going to contact me- I was the oen who had to contact them,

I have had a horrible experience with this camera right from Day one practically, and now the stinking thing is dead, making a bad situation worse. I am not a smart person, nor do I explain things well- but I came here to explain to people that they might run into the horrible issues I've run into, NOT to be berated and made to feel stupid by you- but you seem hell bent on doing so apparently- You';ve done this several times with me in previous threads- not sure what your problem is?

In the uk, any canon repairs are covered by 6 month warranty, can't speak for elsewhere. So if you contact them as mentioned and point out the previous repair, the only cost *might* be the shipping cost. You should of course check as not all canon repair centres globally seem to work the same as this forum demonstrates....

54
Perhaps because if you need a whole bunch of cards, then whether you spend 50 bucks or 150 bucks does make a difference  :D.  And there's no guarantee that you will be able to use your cards in future as different standards come out and manufacturers switch to them....

If you indeed like to rattle off the frames, then the fastest you can afford indeed makes sense....

55
take a look over at magic lantern and there's some posts in the forums comparing video speeds....

In general, as the other posters have stated, your style of shooting needs to either have high framerate for stills shooting, or you're shooting video - not normal, using something like ML.

If you don't tend to do either, save your money  :D

56
EOS Bodies / Re: Canon won't offer a high megapixel body
« on: January 24, 2014, 05:47:53 PM »
Well, that should stir things up a bit.

Here's the setup: Phase One and Hasselblad have announced 50 mp sensors for their large format (I really don't feel that we can refer to these as "medium" format anymore) cameras.


Where did you get the information that Hasselblad had announced 50 MP medium format sensor? As far as I know, it's a CMOS censor that will appear in their new body.
flip over to lu-la (luminous landscape). Both the Phase One and Hassy use the Sony 50mp CMOS sensor...

57
EOS Bodies / Re: Will Canon Answer the D4s? [CR2]
« on: January 11, 2014, 10:02:02 AM »
I'm quite content with the DR of my 5D3 ;D



Lovely shot. But is it only me who feels that a bit more detail in the burnt out sun area would be nicer? A grad filter or change in lighting. Just wondering... I know the hot spot is interesting but JUST A BIT MORE DETAIL perhaps?

Personally, I like it how it is. I might actually increase the glare just a bit. Not every region of a photo needs more detail, sometimes lower detail and less contrast is exactly what you want.

It's a lovely shot and one I really like...but that sky is blown out. An ND grad would render the sky darker and probably lost detail in the darker sky areas. It would have increased contrast where it wasn't wanted. The only way to have fixed this here is to have taken a 2nd photograph but at a 2-3 stop darker exposure and then blended the highlight areas carefully in photoshop using a layer. Shadows can be pulled but clipped highlights are not recoverable. It's also important to render the sky brighter than the foreground, another error I regularly see where ND grads are employed. If an ND grad was used with the above photo, the sky would have been darker than the foreground and wouldn't look right.

Many people here are talking about the D800's extra DR, but the truth is that it's only in the shadows...or rather it's the push-ability in the shadows during post production with low iso noise is really what is being talked about. Highlight clipping / blown highlights occurs at pretty much the same between the 5DIII and D800. So it's not really any extra DR, just better iso thresholds in the deep black areas.

+1 on the picture but it is personal preference. I remember a Pro photographer giving a talk where he describes the best photos as where your eye is drawn into the photo to where you want it. You can take it on a "journey" around the picture, but it never leaves the shot and always comes back to where you want.

I love the car, I get the positioning of the sun, like how the lighting has been done on the car, the slight glare on the roof (don't disagree more might work also) and the composition / low vantage point (tbh far better than I could take) but my eyes still oscillate between the car and the sun, (sorry just personal affliction aka "pet hate").

58
EOS Bodies / Re: Will Canon Answer the D4s? [CR2]
« on: January 11, 2014, 09:52:20 AM »

Personally, I've taken about 55,000 photos at ISO 800 - 3200. I've taken about 15,000 at ISO 400, and less than 10,000 at ISO 100 and 200. Of the ISO 100 photos, I have needed more dynamic range than my 7D offers in about 2000 shots, however I am usually short by maybe one stop (and that is more because of the 7D pixel size...if I had a 5D III, I would have what I need for pretty much everything I've shot before.) In the cases where slight vertical banding noise did show up in the shadows (maybe a couple hundred at most)...I used Topaz DeNoise 5, and was not only able to remove the banding, but I also gained more dynamic range (that's what happens when you reduce noise anyway...you gain DR, but Topaz has a feature that attempts to further recover DR that was lost to shadow noise due to a loss of tonal fidelity, which gains me even more.)

I use GND filtration for my landscape photography, so dynamic range is actually something I have a lot of control over in the field. I would actually greatly appreciate more native sensor DR, as it would reduce my need to use GND filters. It would also help me avoid that unsightly GND artifact where mountaintops end up dark or even black when you need to use more than two to three stops of filtration. That is the single situation where I think having more dynamic range would actually be the most important factor for IQ...ONE situation. I also suspect that tonemapping 14 stops into 8-10 stops without ending up with quirky shifts in contrast and color fidelity would still be very challenging, and I highly doubt I would stop using GND filters even if I had a D800. I still doubt I would push shadows around more than 2-3 stops....but it would be 2-3 stops along with fewer GND filters, which still makes the job easier in the end.

I've been used GNDs for 20+ years, but that's because I have to. However I would not say that gives me control over DR. It allows me to compress it into a range which the sensor can capture. But if you didn't have to use a GND, wouldn't that be better?

Re low ISO - surely the point is that where possible, post processing should be kept to a minimum. It's not the fact that you can push, it's the fact that if you could avoid it, then you can spend more time doing the things you want to, and less effort after.

Third, the more you can see the picture as is, in the field then the less you have to visualise what post processing will do for you.

As a landscape photographer, I would like lower ISO (<100, ideally ISO 12 as I used to shoot in slides), and yes I would like the ability to have better DR and less noise in the picture full stop (but there are also a lot of times where you don't want greater DR and you will reduce it to focus the viewer where you want to)

When I do wildlife, urban or sports the same is true. But that does depend on the shots you are trying to take.

However, does the 1Ds III still take amazingly good photos? Sure does. As does every camera in the last 5-10 years. But is not the point that we still want better/improvements, and aside from the UX/Software features, where else can Canon improve (AF for movies, DR, tracking algorithms)? Like you, I'm not saying it's the end of the world for my photos if I don't have these features - you work with what you have, it's just that it would make it easier.

As for stats on ISO ranges - surely that changes with time? With the 10D I hated going to ISO 200, let alone 400. With a camera today, I'm not bothered about ISO 1600. So I'm not sure that's too helpful.

59
Speedlites, Printers, Accessories / Re: The unbreakable is broken.
« on: December 31, 2013, 04:47:55 AM »
I would suggest the case was damaged before shipping, not during. Given what you say about the box it came in, and everyone's experience, it was like that when it was packed  :(

60
For me, death before your time is tragic no matter the age, the location or the "how"...

He was indeed talented and brave. OP - thank you for sharing the link

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