70

To increase readability and avoid exceeding the answer length limit, this answer has been split across two posts. General information and APS-C cameras are covered in this post; full-frame and APS-H cameras are covered in a separate post below. TL;DR answer In general, Canon DSLRs require a maximum aperture of at least f/5.6 or wider to autofocus, although ...


26

You are asking two very different questions, because Adobe Photoshop Lightroom and Adobe Photoshop of course do not have the same system requirements or use the same system resources. Adobe Photoshop Lightroom 4 Graphics Card: Lightroom does not currently utilize the GPU for performance improvements. It is outlined in the Lightroom documentation here. ...


18

DXOMark primary "scores" are utterly useless. IGNORE THEM. It is a futile effort to try and reduce a complex entity such as a DSLR to a single, scalar number that tells you everything about it. It's a fallacy. There are too many factors to consider, and which factors are most important for a given photographer differ. A single score entirely defeats the ...


14

The reviewer may have used a sample of one. Lenses will vary. The reviewer is measuring scientifically in the lab, pixel peeping using test charts and compiling MTF curves. Owners of the lens are taking vacations shots and pictures of the family dog. the reveiwer has experience with a number of other lenses, including pro lenses. Owners of the 18-200mm? ...


14

I recently got an SSD drive for my primary boot drive. It was a moderately fast one, with consistent 270mb/s read and write speeds. I've used lightroom with the catalog both on the SSD and on a normal HDD, and I did not see a whole lot of performance improvement for my catalog, which is about 12,000 photos or so. As I started investigating how to improve ...


11

Full frame and APS-H cameras For general information and APS-C cameras, see the answer above. Canon EOS 6D All points function to f/5.6. The center point is cross-type, and all other points are single-line. The center point is high-precision cross-type with f/2.8 or faster lenses (but is not dual cross-type as it does not have diagonal-line sensors). ...


11

Overall Score I generally ignore the Overall Score, as it's way too general if you understand any of the individual scores. The Overall Score is a function of a variety of (fairly) deterministic tests, each of which is quite informative, and most (if not all?) have clear units of measurement. But then they generate a "score" that combines these metrics, ...


10

In this very specific case: I found an article on tests of GPU acceleration in Photoshop CS6 from Puget Systems -- a small retailer I'd never heard of, but their methodology seems sound. They actually test with the two video cards you're considering, so this is a very good data source. (The GT610 model they use isn't the mobile version, but reportedly there'...


10

I have actually tested this by separating some of my photos (around 1200) in to another catalogue as I was worried about putting all my eggs in one basked (incase of a failure). I found that there was very little performance increase by doing this, at least, that I could see or measure. My catalogue was ~3100 images in size prior to this. One option I can ...


10

My simplified diagram of camera I/O: |―――――――\ ] \ /----> | CARD 1 | |――――――――――| |―――――――――――――――| |――――――――――――――| | | | | | | ...


8

I would recommend the higher CPU in this case. GPU acceleration in Photoshop itself can make a sizable difference, but only with a good GPU. The 610 is a bare bones "desktop" card that isn't really any better than the 4000. The only advantage it offers is the dedicated video memory, but that's going to have minimal impact when working with most gpu ...


8

A great deal here comes down to the simple fact that most of what's measured in a typical lens test has almost nothing to do with how that lens will perform in real life. First of all, most lens tests emphasize resolution. This gives some idea of the largest print you could produce from a picture and still have it look sharp -- but doesn't tell you much (if ...


8

This kind of fast then slow performance (as you correctly guessed) will be because of the image buffer filling up. Using a faster card will help until you reach the limit of the camera's circuitry - you may have reached this limit. Even if your camera's performance is faster than the SD card. It's quite possible that some of the card's 'bandwidth' is taken ...


8

Two batteries in parallel at the same voltage can supply more current than one of them alone can. If we were talking about car or truck engines we would say we have twice as much torque (current) at the same RPM (voltage). Therefore the same load will not cause the same drop in voltage when two of the same batteries are in parallel. This also means a greater ...


7

Given that you have a Canon, the lower RAW modes, mRAW and sRAW, DO INDEED UTILIZE ALL of the available sensor pixels to produce a richer result without the need for bayer interpolation. The actual output format, while it is still contained within a .cr2 Canon RAW image file, is encoded in a Y'CbCr format, similar to many video pulldown formats. It stores ...


7

The speed of the memory card is definitely one constraining factor but as you suspect there are other bottlenecks. First there is the internal memory buffer of the camera. Each camera only has so much RAM installed. When you shoot this buffer is filled first and the camera does what it can to quickly empty the buffer to allow for more shooting. The size of ...


7

Consider this: If your camera had twice as much buffer memory it would be able to take roughly twice as many photos before running out of memory, but it would also then take roughly twice as long for the buffer to clear. So after the initial extra 5-10 shots twice a deeper buffer would allow, you would then still be limited to the exact same frame rate you ...


5

My answer: disk! Just some real world observation: I am a user of both Lightroom and Photoshop and recently upgraded from a 4 year old high-end Acer desktop to now a massive Alienware desktop with the ultra powerful GTX960 video card. Note that I do not have this high-end desktop for Photoshop, but still, there is no visible performance improvement in ...


5

There are two main things I can think of, the first is the autofocus. On a DSLR, the mirror reflects light on to a Phase Detect Auto Focus sensor while you are looking in the view finder. While PDAF isn't as accurate as contrast based detection (which can be done with a standard CMOS sensor) it is much faster. Since mirrorless lack the mirror, they ...


4

A SSD will boost all read and write operations to and from disk. The data transfer rate on a SSD is, depending on the model, between 100MB/s and 500 MB/s, while hard disks provide about 100MB/s. Latency and access times to your data on the disk are massively faster than on a hard disk. Early SSD models did lose speed the fuller the disk got, current models ...


4

Tim Grey, whom I would consider a reliable source, once stated in his newsletter: Adobe indicates there is no practical limit to catalog size from a performance perspective, and I can tell you from experience that even with 283,669 in a catalog, performance remains good. This was a little more than one year ago and he referred to recent versions of ...


4

A camera can only write out information so fast. So once you have a card that can be written to as fast as the camera can write out there is no benefit to getting a faster card. The I/O bottleneck is on the camera side. The only benefit you'll see is when it comes to reading off the card onto the computer. Whether that benefit is worth the cost difference is ...


4

Are you wondering about the distinct list of keywords in an entire catalog or are you wondering about the number of keywords for a single image? I am doubtful that there is any practical limit to the number of keywords allowed in a Lightroom catalog. It wouldn't make sense to have an artificial limit in the software itself but it is possible. Lightroom is ...


4

As the camera theoretically has to make the double amount of writes, is there a performance impact? (especially whilst shooting RAW continuous and filling the buffer). There almost always is a performance penalty. How significant it is can vary widely from one camera model to the next. The only exception would be if both slots support the same type of card, ...


4

Bob Parent's first camera that he used in the jazz clubs of New York was a 4x5 Speed Graphic. It is also known that when he first started, he used a flash held in his left hand as far off camera as he could reach. Although most photographers who used flash with a Speed Graphic had it attached to the side of the camera, the flash was triggered by an external ...


3

I tried this experiment, and found that performance was effectively unchanged with two catalogs, where one was about 1/10 the size of the other. What really made me give the experiment up, though, was all the hidden costs to doing this: If you want to share keyword hierarchies between the libraries, now you have to spend time exporting and importing ...


3

The SSD makes a really huge difference on my system but it is a Windows 7 64-bit machine, so the file-system is different from yours. The thing is I kept the regular HDD for the boot drive and another two (RAID-0) for data (not photos). The SSD is used by Lightroom exclusively :) and it does not have much room left already since I could only afford 240GB ...


3

I think what you're seeing here is the difference between an objective review and subjective reviews. The DPreview review includes a highly technical interactive diagram showing exactly how the image quality varies with focal length and aperture, with actual photos taken with the lens to demonstrate this. The statements you quote are statements of measured ...


3

Just wanted to point that the information about focus points in EOS 600D/550D/500D/450D might not be accurate. " Canon EOS Digital Rebel XTi (400D), Rebel XSi (450D), Rebel T1i (500D), Rebel T2i (550D), Rebel T3i (600D), 30D The center point is high-precision cross-type only when the aperture is at least f/2.8. If below f/2.8 but at least f/5.6, all points ...


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