Prospec 32Gb UDMA 7 CF

 The Prospec 32Gb UDMA 7 Compact Flash Card from Calumet – review

The Prospec 32Gb UDMA 7 Compact Flash Card

The Prospec 32Gb UDMA 7 Compact Flash Card from Calumet – click image to visit the product order page.

Because I’m something of a photographic ‘old fart’ and have been taking images for a living since before the venerable A1 was a glimmer in some Canon engineers eye, I treat everything new with suspicion!

Back in those days when we shot on film, suspicious gits like me had our favourite films we used.  These were whittled down from the vast array on offer, not only on the basis of their performance, but also on reliability.

Did the sprocket holes tear in a particular cameraif they did then to avoid imminent disaster you’d never put that film in that camera.

Were the ‘tails’ always taped to the cassette spool? Christ, that one nearly cost me a boat-load of money at a wedding once – both bride and groom were barristers!

Thank the Lord we don’t have problems like that any more.

But CF cards come with their equivalent problem – card failure.

CF cards are basically Flash RAM, just like SSDs in the latest computers.  And as such they are prone to some degree of instant failure over time.

 The Way I Use Camera Storage Media

When I’ve finished shooting something I move it from the camera storage to my main imaging machine as soon as possible.  Once the shots are on the computer, the card goes back in the camera and is immediately reformatted.

Back when the D3 was Nikon’s flagship I’d had some clonking failures of Lexar CF cards and Sandisk Ultras, when Kevin Treadwell at TFC Birmingham put me on to Delkin cards – and I have never had a problem with them………(see footnote)…

And the two original 16Gb Delkins I bought for the D3 are still going strong to this day!

So when I eventually moved to the D4 I wanted a 32Gb Delkin UDMA 7 to go with the 32Gb Sony XQD, but I couldn’t locate one anywhere.

I was moaning about this to Stuart Tudor-Wood at Calumet Birmingham and he suggested I tried their own Prospec 32Gb UDMA 7 instead.

Can you imagine what the “suspicious old photography fart” in me was saying; I was used to possibly the most reliable memory on the planet, and the priciest; and here was something I’d never heard of, and costing pretty much the same..

I did manage to walk out of the door without paying for it, so that was a small victory – but it only lasted 3 weeks until I was doing another workshop there – he nailed me for it the minute I walked through the door!

So, here we are, two years later.  The other day I realised how long I’d had this card in regular use.  It’s a mighty rare occurrence for me to have a day shooting long lens action and not generate some use of the CF card.

Even if I’ve only shot to the XQD card, force of habit leads me to format both cards one after the other.

And if I’m going to shoot video I shoot that to the XQD and then remove it if I want to shoot stills, which consequently go to the CF card.

When I’m testing lenses and shooting for workshop slides etc I shoot to the CF card, then stick that in my steam-powered laptop – it can never see my XQD reader and I daren’t even think about asking it to accommodate tethered shooting..

I bought the card a new brother so I had two of them in the 1DX when I went to Norway in February this year.

All in all, looking back through all the image batches I’ve shot I reckoned that this one card had been reformatted 981 times in a selection of camera bodies from a 1DX and 5DMk3 to a D4S, D4, D800, D800E and D810.

In the D4 this card allows me to shoot 41 14bit uncompressed raw files before I hit the end of the camera buffer; which let’s face it, is plenty.

So I promptly set about shooting 20 bursts of 41 frames, wiping the card between bursts, just so that I could say with some degree of certainty that the card had just hit its 1000th reformat.

Now THAT is a good, solid and highly reliable card that has put up with more abuse in the last two years than some of my clients would give their CF cards in a lifetime.

What Do The ‘Hieroglyphics’ All Mean?

I must admit to being somewhat ambivalent to the majority of these speed numbers – at the end of the day, as a photographer you are more interested in sustained write speed than you are in read speed – or at least you should be.

The faster the write speed of the media the longer it takes to hit the end of the camera internal buffer – this means you shoot more sequential frames in a burst.

CF6

This logo means the media is compliant with the CFA’s CF6 specification, which is supposed to provide data transfer rates of 167Mb/sec.

But that quoted transfer rate could be either read or write – they never seem to commit!

CF6 specification means UDMA 7 compliance; whereas UDMA 6 equated to CF 5 specification and transfer speeds of 133Mb/sec.

CF cards have to communicate with a host device – in our case our camera; and UMDA is the most efficient and fastest mode of communication. But not ALL cameras are UDMA compliant.  And those that are might not be UDMA 7 compliant.

If a camera is not UDMA compatible then believe it or not, a slower non-UDMA card might make the camera work faster. If you put a UDMA 7 card in a camera that is only UDMA 6 compliant then that’s fine, but communication between the two will be at UDMA 6 speeds.

The moral here is to check your camera specifications, and available firmware upgrades.

What does 1010x mean? Known as the card Commercial X Rating it’s an indication of read speed more than anything else, and basically relates the speed of the card as a multiple of the old CD-ROM standard of 150KBs.  So 1010x equates to 151.15Mbs.

But here’s the thing; none of these speeds, theoretical or otherwise, are derived via a camera – they are all acquired on a test-bench computer and a variety of card interfaces.

There is a simple if slightly ‘rough ‘n ready’ test that you can do to check the camera/media combo write speed:

  1. Set the camera to its fastest RAW shooting frame rate (Canon 1DX users note, that’s NOT 14fps!).
  2. Set the burst length to 30 frames.
  3. Put the camera in manual mode, auto iso, and set the shortest shutter speed.

Get a stop-watch and be prepared to start it when the ‘data write’ indicator lights up.

Press and hold the shutter button to start the burst of exposures, take your finger off the shutter button when the camera stops shooting.  The indicator light will still be on, and the stop watch should still be running.  Stop the clock when the light goes out!

Multiply the number of frames by the size of your RAW file, then divide the result by the time in seconds and you’ll have a rough value for your data write speed in Mb/sec.

In a Canon 1DX the Prospec 32Gb UDMA 7 CF card chugs away at a highly respectable 69Mbs write speed.

32Gb of storage with great reliability and ‘real world’ write speed like that is great – especially for the price.

Nikon Users

If, like me, you mainly shoot uncompressed 14 bit RAW (not an option for Canon shooters) the write speed of the Prospec 32Gb UDMA 7 CF card in a D4/4S will drop to around 41Mbs due to the much increased file size of each RAW frame – 35.9Mb average RAW size, as opposed to the 1DX average file size of around 26.4Mb.

But sensible burst shooting in conjunction with the huge Nikon D4/4S buffer means you will never suffer from ‘buffer lock-out’.

Conclusion

Bearing in mind that this is just my opinion, the Prospec 32Gb UDMA 7 CF card represents exceptionally good value for money.  Yes, there are faster cards out there; but I’ve been bitten by both S****** and L**** in the past, and ‘once bitten twice shy’ and all that……

For me the write/format longevity of this card is what strikes me the most, and for the price this card is well worthy of anyone’s consideration.

Prospec 32Gb UDMA 7 CF card,Andy Astbury,Wildlife in Pixels

Two years and over 1000 reformats, the Prospec 32Gb UDMA 7 CF card is still going strong – have a Kite!

Footnote

I’ve just had it confirmed……..the Prospec is actually Delkin; so bearing in mind what I said earlier, the reliability comes as no surprise!

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Bit Depth

Bit Depth – What is a Bit?

Good question – from a layman’s point of view it’s the smallest USEFUL unit of computer/digital information; useful in the fact that it can have two values – 0 or 1.

Think of it as a light switch; it has two positions – ON and OFF, 1 or 0.

bit, Andy Astbury, bit depth

A bit is like a light switch.

We have 1 switch (bit) with 2 potential positions (bit value 0 or 1) so we have a bit depth of 1. We can arrive at this by simple maths – number of switch positions to the power of the number of switches; in other words 2 to the 1st power.

How Does Bit Depth Impact Our Images:

So what would this bit depth of 1 mean in image terms:

Andy Astbury,bit depth,

An Image with a Bit Depth of 1 bit.

Well, it’s not going to win Wildlife Photographer of the Year is it!

Because each pixel in the image can only be black or white, on or off, 0 or 1 then we only have two tones we can use to describe the entire image.

Now if we were to add another bit to the overall bit depth of the image we would have 2 switches (bits) each with 2 potential values so the total number of potential values, so 2 to the 2nd, or 4 potential output values/tones.

Andy Astbury,bits,bit depth

An image with a bit depth of 2 bits.

Not brilliant – but it’s getting there!

If we now double the bit depth again, this time to 4 bit, then we have 2 to the 4th, or 16 potential tones or output values per image pixel:

Andy Astbury,bits,bit depth

A bit depth of 4 bits gives us 16 tonal values.

And if we double the bit depth again, up to 8 bit we will end up with 2 to the 8th power, or 256 tonal values for each image pixel:

Andy Astbury,bits,bit depth

A bit depth of 8 bits yields what the eye perceives to be continuous unbroken tone.

This range of 256 tones (0 to 255) is the smallest number of tonal values that the human eye can perceive as being continuous in nature; therefore we see an unbroken range of greys from black to white.

More Bits is GOOD

Why do we need to use bit depths HIGHER than 8 bit?

Our modern digital cameras capture and store RAW images to a bit depth of 12 bit, and now in most cases 14 bit – 4096 & 16,384 tonal values respectively.

Just as we use the ProPhotoRGB colour space to preserve as many CAPTURED COLOURS as we can, we need to apply a bit depth to our pixel-based images that is higher than the capture depth in order to preserve the CAPTURED TONAL RANGE.

It’s the “bigger bucket” or “more stairs on the staircase” scenario all over again – more information about a pixels brightness and colour is GOOD.

Andy Astbury,bits,bit depth,tonal range,tonality,tonal graduation

How Tonal Graduation Increases with Bit Depth.

Black is black, and white is white, but increased bit depth gives us a higher number of steps/tones; tonal graduations, to get from black to white and vice versa.

So, if our camera captures at 14 bit we need a 15 bit or 16 bit “bucket” to keep it in.  And for those who want to know why a 14 bit bucket ISN’T a good idea then try carrying 2 gallons of water in a 2 gallon bucket without spillage!

The 8 bit Image Killer

Below we have two identical grey scale images open in Photoshop – simple graduations from black to white; one is a 16 bit image, the other 8 bit:

Andy Astbury,bits,bit depth,tone,tonal graduation

16 bit greyscale at the top. 8 bit greyscale below – CLICK Image to view full size.

Now everything looks OK at this “fit to screen” magnification; and it doesn’t look so bad at 1:1 either, but let’s increase the magnification to 1600% so we can see every pixel:

 

Andy Astbury,bits,bit depth,tone,tonal range,tonal graduation

CLICK Image to view full size. At 1600% magnification we can see that the 8 bit file is degraded.

At this degree of magnification we can see a huge amount of image degradation in the lower, 8 bit image whereas the upper, 16 bit image looks tonally smooth in its graduation.

The degradation in the 8 bit image is simply due to the fact that the total number of tones is “capped” at 256. and 256 steps to get from the black to the white values of the image are not sufficient – this leaves gaps in the image that Photoshop has to fill with “invented” tonal information based on its own internal “logic”….mmmmmm….

There was a time when I thought “girlies” were the most illogical things on the planet; but since Photoshop, now I’m not so sure…!

The image is a GREYSCALE – RGB ratios are supposedly equal in every pixel, but as you can see, Photoshop begins to skew the ratios where it has to do its “inventing” so we not only have luminosity artifacts, but we have colour artifacts being generated too.

You might look upon this as “pixel peeping” and “geekey”, but when it comes to image quality, being a pixel-peeping Geek is never a bad thing.

Of course, we all know 8bit as being “jpeg”, and these artifacts won’t show up on a web-based jpeg for your website; but if you are in the business of large scale gallery prints, then printing from an 8 bit image file is never going to be a good idea as these artifacts WILL show on the final print.

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