Will I benefit from using very fast (> 30 MB/s) SD cards in a non-UHS enabled camera?

Question

Will I benefit from using a very fast SD card, such as this SanDisk Extreme Pro card, in my non-UHS enabled camera (a Pentax K-5)? I do not have any devices that can take advantage of UHS speeds. Will there be a performance advantage, even if small, from using such a card?

This is a more generalized version of this question: Can I get faster and cheaper results by buying the Sandisk Extreme, not the newer Pro?

Asked by DragonLord

Answer

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 a personal decision.

Honestly, for me, I generally stick with slower cards. The camera buffer is large enough to handle short bursts and by the time I'm ready for another burst the card has had sufficient time to clear the buffer.

Answered by nwcs

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Why does a DSLR stop shooting continuously after a few seconds?

Question

In continuous shooting, all cameras I used shoot for a few seconds, then stop. For example, a Nikon D7000 with a 200x (30 MB/s) single SD card makes ten RAW photos (approx. 19 MB each), six shots per second, then stops for a few seconds when the buffer is full.

Obviously, the SD card is too slow. But is the SD card the only bottleneck, or does it stop shooting also because the camera cannot process more images?

In other words, if I buy a 600x (90 MB/s) SD card or an even faster one, how this will influence the number of shoots per burst?

Asked by MainMa

Answer

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 the buffer generally correlates to the price of the camera. A professional DSLR will have a larger buffer than a consumer DSLR.

The size of the file being recorded affects how many images can be in the buffer before you experience the slowdown. So capturing 14 bit raw means you hit the wall much faster than 8 bit size optimized jpeg.

So that leads to your main question: will a faster memory card help in burst mode. Yes, it helps. But only to a point. Keep in mind that writing to memory in the camera is orders of magnitude faster than writing to a flash memory card. So having a faster card gets you a little more burst but not as much as you'd get from capturing significantly smaller files.

I'm mobile right now and can't do the math but my experience with UDMA and slower cards suggest that the faster card helps but it isn't a night and day experience.

Answered by nwcs

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How do you reconcile generally positive user comments with negative comments in a review?

Question

My question was prompted by this DPReview review of the Nikon DX 18~200mm, wherein on page 3 the author reveals some significant sharpness and distortion issues, leading to final assessments of

Pronounced distortion across much of the range

and

Extremely soft at 135mm

These seem like major problems to my beginner eyes... yet one can find many, many satisfied owners around the internet, see B&H's store page to give one example.

These two realities - that of the carefully tested review and the cumulative experience of the masses - seem quite difficult to reconcile in this particular case.

If we assume the reviewer is competent and the lens tested is representative of the model's performance at large...

• are the reviewer's standards out of touch with all but the most serious photographers?
• or is this subtle, widespread (perhaps even subliminal) buyer's remorse performance bias based on the relatively high cost (for DX) of this lens?
• something else entirely?

Answer

• 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? It may be the only lens they own.

• the reviewer is measuring 1% distortion that most users will not see in real life images. Most wouldn't know what pincushion distortion is, or notice it unless you pointed it out. I have the lens and distortion is only noticeable to me in shots of brick walls or skyscrapers, and photoshop corrects it anyway!

• the reviewer is using test charts meant to expose any weaknesses in the lens. An owner of the lens is just taking pictures in real life situations and probably can't tell which images were taken with the 18-200mm and which were with the 50mm prime. I can't, not in terms of sharpness or distortion.

• the reviewer is judging the quality of the lens vs cost to arrive at a overall value relative to other lenses. He will no doubt think it's pricey and may judge that you could obtain a better value (either sharper or less expensive). But an owner of the lens has already paid (or overpaid) and paid the credit card bill and they're not concerned about how it compares on a test chart against another lens. They're taking pictures, and able to zoom to 200mm or out to 18mm and catch shots they wouldn't get if they had to switch lenses, or left the other lenses at home.

• I would also wager than 90% of amateur photographers don't know about or care about vignetting or chromatic aberration either. Even the trendy bokeh is probably not in most people's vocabulary :)

I bought the lens expecting it to be reasonably sharp, but mainly versatile and convenient, for a walk about lens. It's amazing that a super zooms exist IMO, much less that they are reasonably sharp. If I had experience using professional lenses, I might feel this lens was a bit soft or slow. But hey, it's basically a kit lens. Most of the people buying these are not pros and not interested in test charts.

What he says about distortion is probably true of all samples. Not sure about the softness at 135mm, I've not noticed it, and other reviewers like Thom Hogan didn't mention it. To be honest, I use the lens mainly between 18-50mm, and occasionally zoom out to 200mm to get some detail. I would rarely use 135mm.

I have done basic testing of my 18-200 at 50mm f/8 and compared to my prime 50mm at f/8. I didn't use a proper test pattern, but some newspaper. To my eye they were almost the same. The prime had a bit more contrast, and slightly sharper. If it had been a normal picture of a landscape I don't know if I could tell them apart to be honest.

As much as I love the my 85mm prime and a few others, if I could only own one lens I guess I'd stick with the 18-200mm for versatility. For that versatility it's worth the price IMO. So I'd give it a good review, but if I worked for dpreview and had all the gear to measure it against a database of other lenses, I might be more lukewarm in my assessment.

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Will an SSD provide a noticeable benefit for Lightroom over a traditional harddrive?

Question

I am a huge Lightroom (3.6) user, and have a 2006 2.15 Ghz Core 2 Duo 24" iMac, running Lion. This Mac it limited to 3GB RAM max, but does have dedicated graphics. I have about 50GB left on my harddrive. I have over 21,000 images in my LR catalog. The catalog itself is local on my iMac hard drive, but images are on attached storage.

My issue is that I have been having some noticeable performance issues with Lightroom. Dragging sliders can be jumpy at times, and sometimes switching modules has significant delays. I suspect that overhead in Lion is somewhat to blame, but it may also be all the files and apps on my Mac.

So, question is: does anyone have tested evidence of an SSD vs harddrive on Lightroom performance? How dependent is Mac OSX on free hard drive space when it pages to virtual memory? How much free space is preferred?

Or is my issue more related to LR itself, in that I have over 21,000 images in my LR catalog? Would I see noticeable improvement in the interface with a smaller catalog?

Trying to decide if the pain of opening my iMac and installing an SSD is worth it, or if I should instead save the $$ and put it toward an updated iMac in the future.

Answer

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 the performance of Lightroom, I realized that the most significant factor that affected performance was the Camera RAW Cache size (Preferences -> File Handling -> Camera Raw Cache Settings -> Maximum Size). It defaults to 1Gb, however when working with a large number of RAW photos, a 1Gb cache is FAR, FAR too small. Increasing it to at least 20Gb offered good improvement, and increasing it to 50Gb offered considerable improvement. The improvement was a bit better on the SSD, however given the value of SSD space, I again moved the cache off onto a normal HDD. The performance gains are still evident, and I'm quite happy using LR with all of its data on a normal hard drive.

It should be noted that SSD's come in a very BROAD range of speeds and capabilities. Some are fairly slow relative to an HDD (which can usually offer around 60mb/s burst rates), where as some are insanely fast. SSD burst rates can range from as low as around 100mb/s or even lower for really cheap drives, to as high as 700mb/s or even more for highly specialized designs...such as those that fit into a PCI-E slot. Some SSD's include built-in high-speed secondary caches, some have better data distribution algorithms that optimize read or write speeds, etc. All these factors can affect whether an SSD might show a significant improvement for Lightroom performance or not. Lightroom generally stores the working image in memory, so if you are worried about single-image development speed, an SSD is not going to help much. The performance gains that can be realized from faster storage drive speeds happen when moving between files, performing multi-file operations, etc. The bottom line is...the more money you are willing to spend for better SSD technology and faster burst rate, the more likely you are to see an improvement.

Check more discussion of this question.

Will an SSD provide a measurable benefit for Lightroom over a traditional harddrive?

Question

I am a huge Lightroom (3.6) user, and have a 2006 2.15 Ghz Core 2 Duo 24" iMac, running Lion. This Mac it limited to 3GB RAM max, but does have dedicated graphics. I have about 50GB left on my harddrive. I have over 21,000 images in my LR catalog. The catalog itself is local on my iMac hard drive, but images are on attached storage.

My issue is that I have been having some noticeable performance issues with Lightroom. Dragging sliders can be jumpy at times, and sometimes switching modules has significant delays. I suspect that overhead in Lion is somewhat to blame, but it may also be all the files and apps on my Mac.

So, question is: does anyone have tested evidence of an SSD vs harddrive on Lightroom performance? How dependent is Mac OSX on free hard drive space when it pages to virtual memory? How much free space is preferred?

Or is my issue more related to LR itself, in that I have over 21,000 images in my LR catalog? Would I see noticeable improvement in the interface with a smaller catalog?

Trying to decide if the pain of opening my iMac and installing an SSD is worth it, or if I should instead save the $$ and put it toward an updated iMac in the future.

Answer

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 the performance of Lightroom, I realized that the most significant factor that affected performance was the Camera RAW Cache size (Preferences -> File Handling -> Camera Raw Cache Settings -> Maximum Size). It defaults to 1Gb, however when working with a large number of RAW photos, a 1Gb cache is FAR, FAR too small. Increasing it to at least 20Gb offered good improvement, and increasing it to 50Gb offered considerable improvement. The improvement was a bit better on the SSD, however given the value of SSD space, I again moved the cache off onto a normal HDD. The performance gains are still evident, and I'm quite happy using LR with all of its data on a normal hard drive.

It should be noted that SSD's come in a very BROAD range of speeds and capabilities. Some are fairly slow relative to an HDD (which can usually offer around 60mb/s burst rates), where as some are insanely fast. SSD burst rates can range from as low as around 100mb/s or even lower for really cheap drives, to as high as 700mb/s or even more for highly specialized designs...such as those that fit into a PCI-E slot. Some SSD's include built-in high-speed secondary caches, some have better data distribution algorithms that optimize read or write speeds, etc. All these factors can affect whether an SSD might show a significant improvement for Lightroom performance or not. Lightroom generally stores the working image in memory, so if you are worried about single-image development speed, an SSD is not going to help much. The performance gains that can be realized from faster storage drive speeds happen when moving between files, performing multi-file operations, etc. The bottom line is...the more money you are willing to spend for better SSD technology and faster burst rate, the more likely you are to see an improvement.

Check more discussion of this question.

Does anyone have any tips to make Lightroom run faster?

Question

I'm running Lightroom 2.6 on Windows XP and it runs painfully slow. Just navigating from one image to the next takes a few seconds.

What can I do to speed it up?

Answer

Don't let the catalogue grow too large.

Separating your pictures into several catalogues can bring a lot of speed.

For me the main waiting point is waiting for Lightroom to render the 1:1 previews - if I let Lightroom render those on import I can usually work faster.

Of course putting the catalogue on a fast hard disk (SSD) helps, too.

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Will converting images to DNG improve post-processing performance in Lightroom?

Question

I would like to know if converting my RAW files to DNG will improve the overall speed of Lightroom. The most painful issue is that it takes between 5 and 10 seconds to get my 1:1 image rendered when I zoom on it. I should add that my LR is configured so that it creates the 1:1 preview during importing of the files.

I use a MacBook Pro, Canon's RAWs, Lighroom 3.2. Thanks :)

Answer

All image previews are stored as JPEG files of various sizes inside of a .lrprev file. The loading speed of the preview images will likely not change much if you switch to DNG. The benefit of DNG is that it is an open standard format, and can keep the metadata in the same file as the image data, which simplifies portability. On the flip side, you would incur not only the extra cost of generating 1:1 previews on import, but also converting from your native RAW to DNG raw.

You also have to consider that DNG stores image data in a specific way, using integer values for pixel data. That will generally work for most sensors, however there are some special sensors that use non-square bayer arrays, make use of extra luminance pixels, or might possibly use floating point numbers rather than integers to store individual pixel values. At the very least, if you convert to DNG, you should keep your original RAW images around.

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Does shooting at lower RAW resolution using crop sensor camera mimics qualities of full frame cameras?

Question

I'm not talking about changes to the focal length.

I've read many post that say in full frame camera the pixel density is lower compared to crop sensor camera's and so it captures more light and has thus has better ISO performance and greater dynamic range. So if I change by crop sensor camera to shoot at a lower resolution, will that equate to a better pixel density and mimic the performance of a full frame (or medium format) or will it always shoot at maximum resolution and the reduce the size?

--EDIT: 1--
I've a Canon 60D and I've 3 options for RAW image sizes (RAW, M-RAW amd S-RAW). If RAW is just a dump from the Camera sensors, How can their be 3 different sizes? Does the camera also scale down RAW images as well?

Answer

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 luminance information for each FULL pixel (2x2 quad of 1 red, 1 blue, and 2 green pixels), and each chrominance channel is derived from half pixel data (1x2 pair of 1 red+1 green or 1 blue+1 green).

I am not exactly certain what the specific low-level hardware read and encoding differences between mRAW and sRAW are, however generally speaking the smaller the output format, the more sensor pixel input information you can use for each output pixel. The small amount of interpolation present in m/sRAW is moot, as both formats interpolate far less than native RAW. It should also be noted that neither mRAW nor sRAW are actual "RAW" formats in the normal sense...sensor data IS processed and converted into something else before it is saved to a .cr2 file.

For more details about YUV derived formats and Canon sRAW, see my answer here: Why isn't the xvYCC color space seeing uptake for still photography?

From "Understanding What is stored in a Canon RAW .CR2 file":

The sRaw format (for "small RAW") was introduced with the 1D Mark III in 2007. It is a smaller version of the RAW picture.

For the 1D Mark III, then the 1Ds Mark III and the 40D (all with the Digic III), the sRaw size is exactly 1/4 (one fourth) of the RAW size. We can thus suppose than each group of 4 "sensor pixels" is summarized into 1 "pixel" for the sRaw.

With the 50D and the 5D Mark II (with the Digic IV chip), the 1/4th size RAW is still there (sRaw2), and a half size RAW is also appearing : sRaw1. With the 7D, the half size raw is called mraw (same encoding as sraw1), 1/4th raw is called sraw (like the sraw2).

the sRaw lossless Jpeg is always encoded with 3 colors component (nb_comp) and 15 bits.

Jpeg code of Dcraw was first modified (8.79) to handle sRaw because of the h=2 value of the first component (grey background in the table). Normal RAW have always h=1. Starting with the 50D, we have v=2 instead of v=1 (orange in the table). Dcraw 8.89 is the first version to handle this and the sraw1 from 50d and 5D Mark II.

"h" is the horizontal sampling factor and "v" the vertical sampling factor. It specifies how many horizontal/vertical data unit are encoded in each MCU (minimum coded unit). See T-81, page 36.

3.2.1 sRaw and sRaw2 format

h=2 means that the decompressed data will contain 2 values for the first component, 1 for column n and 1 for column n+1. With the 2 other components, decompressed sraw and sraw2 (which all have h=2 & v=1), always have 4 elementary values

[ y1 y2 x z ] [ y1 y2 x z ] [ y1 y2 x z ] ...
(y1 and y2 for first component)

Every "pixel" in sRAW and mRAW images contain four components...a split Y' component (y1 and y2), as well as an x (Chrominance Blue) and z (Chrominance Red). All four components (from a 1/2 image perspective, sRAW1/mRAW) have a column height of 2 (h) and a width of 1 (v). This indicates that the Luminance value (Y') is comprised of a FULL 2x2 pixel quad...or two 2x1 pixel columns stored in y1 and y2.

The references below do not seem to specifically state this, so I am speculating a bit here, however with the sRAW2 (1/4 raw) I believe Luminance information would be derived from a 4x4 pixel block where h=4 and v=2. Encoding chrominance would get more complex at a 1/4 size image, as the bayer color filter array on the sensor is not arranged in neat red and blue columns. I am unsure whether alternating 2x1 height columns are processed for each Cr and Cb component, or if some other form of interpolation is performed. One thing is certain...the interpolation of source data is always larger than the output data, and no overlapping (as in normal bayer interpolation) occurs as far as I can tell.

Finally, sRAW1/mRAW and sRAW/sRAW2 are compressed using a lossless compression algorithm. This is a critical distinction between these formats and JPEG, which also uses a ycc type encoding. JPEG performs lossy compression, making it impossible to restore pixels back to their exact original representation. Canon's s/mRAW formats are indeed able to be restored back to original full precision 15-bit image data.

References:

• Understanding What is stored in a Canon RAW .CR2 file, How and Why
  • For pulldown details, see text just before section 3.2.1
• DIGITAL COMPRESSION AND CODING OF CONTINUOUS-TONE STILL IMAGES – REQUIREMENTS AND GUIDELINES

Check more discussion of this question.

Does shooting at lower RAW resolution using crop sensor camera mimics qualities of full frame cameras?

Question

I'm not talking about changes to the focal length.

I've read many post that say in full frame camera the pixel density is lower compared to crop sensor camera's and so it captures more light and has thus has better ISO performance and greater dynamic range. So if I change by crop sensor camera to shoot at a lower resolution, will that equate to a better pixel density and mimic the performance of a full frame (or medium format) or will it always shoot at maximum resolution and the reduce the size?

--EDIT: 1--
I've a Canon 60D and I've 3 options for RAW image sizes (RAW, M-RAW amd S-RAW). If RAW is just a dump from the Camera sensors, How can their be 3 different sizes? Does the camera also scale down RAW images as well?

Answer

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 luminance information for each FULL pixel (2x2 quad of 1 red, 1 blue, and 2 green pixels), and each chrominance channel is derived from half pixel data (1x2 pair of 1 red+1 green or 1 blue+1 green).

I am not exactly certain what the specific low-level hardware read and encoding differences between mRAW and sRAW are, however generally speaking the smaller the output format, the more sensor pixel input information you can use for each output pixel. The small amount of interpolation present in m/sRAW is moot, as both formats interpolate far less than native RAW. It should also be noted that neither mRAW nor sRAW are actual "RAW" formats in the normal sense...sensor data IS processed and converted into something else before it is saved to a .cr2 file.

For more details about YUV derived formats and Canon sRAW, see my answer here: Why isn't the xvYCC color space seeing uptake for still photography?

From "Understanding What is stored in a Canon RAW .CR2 file":

The sRaw format (for "small RAW") was introduced with the 1D Mark III in 2007. It is a smaller version of the RAW picture.

For the 1D Mark III, then the 1Ds Mark III and the 40D (all with the Digic III), the sRaw size is exactly 1/4 (one fourth) of the RAW size. We can thus suppose than each group of 4 "sensor pixels" is summarized into 1 "pixel" for the sRaw.

With the 50D and the 5D Mark II (with the Digic IV chip), the 1/4th size RAW is still there (sRaw2), and a half size RAW is also appearing : sRaw1. With the 7D, the half size raw is called mraw (same encoding as sraw1), 1/4th raw is called sraw (like the sraw2).

the sRaw lossless Jpeg is always encoded with 3 colors component (nb_comp) and 15 bits.

Jpeg code of Dcraw was first modified (8.79) to handle sRaw because of the h=2 value of the first component (grey background in the table). Normal RAW have always h=1. Starting with the 50D, we have v=2 instead of v=1 (orange in the table). Dcraw 8.89 is the first version to handle this and the sraw1 from 50d and 5D Mark II.

"h" is the horizontal sampling factor and "v" the vertical sampling factor. It specifies how many horizontal/vertical data unit are encoded in each MCU (minimum coded unit). See T-81, page 36.

3.2.1 sRaw and sRaw2 format

h=2 means that the decompressed data will contain 2 values for the first component, 1 for column n and 1 for column n+1. With the 2 other components, decompressed sraw and sraw2 (which all have h=2 & v=1), always have 4 elementary values

[ y1 y2 x z ] [ y1 y2 x z ] [ y1 y2 x z ] ...
(y1 and y2 for first component)

Every "pixel" in sRAW and mRAW images contain four components...a split Y' component (y1 and y2), as well as an x (Chrominance Blue) and z (Chrominance Red). All four components (from a 1/2 image perspective, sRAW1/mRAW) have a column height of 2 (h) and a width of 1 (v). This indicates that the Luminance value (Y') is comprised of a FULL 2x2 pixel quad...or two 2x1 pixel columns stored in y1 and y2.

The references below do not seem to specifically state this, so I am speculating a bit here, however with the sRAW2 (1/4 raw) I believe Luminance information would be derived from a 4x4 pixel block where h=4 and v=2. Encoding chrominance would get more complex at a 1/4 size image, as the bayer color filter array on the sensor is not arranged in neat red and blue columns. I am unsure whether alternating 2x1 height columns are processed for each Cr and Cb component, or if some other form of interpolation is performed. One thing is certain...the interpolation of source data is always larger than the output data, and no overlapping (as in normal bayer interpolation) occurs as far as I can tell.

Finally, sRAW1/mRAW and sRAW/sRAW2 are compressed using a lossless compression algorithm. This is a critical distinction between these formats and JPEG, which also uses a ycc type encoding. JPEG performs lossy compression, making it impossible to restore pixels back to their exact original representation. Canon's s/mRAW formats are indeed able to be restored back to original full precision 15-bit image data.

References:

• Understanding What is stored in a Canon RAW .CR2 file, How and Why
  • For pulldown details, see text just before section 3.2.1
• DIGITAL COMPRESSION AND CODING OF CONTINUOUS-TONE STILL IMAGES – REQUIREMENTS AND GUIDELINES

Check more discussion of this question.

How do I turn off lens correction in Lightroom 3?

Question

I'm trying to improve Lightroom performance on my Mac and have read that turning off Lens Correction can help the "Loading" times in the develop module.

I really don't care about lens correction and shoot "lomo", so how do I turn off this feature in Lightroom 3?

Answer

When in Develop, there is a Lens Correction panel. Within this panel you can turn profile lens correction on or off using the Enable Profile Corrections checkbox

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