CF vs. SD card image quality

Sorry if this has been answered before but I was wondering if there has ever been any testing done to see if there any difference in image quality when an identical image is saved to and SD and a CF card? I'm not talking about saving the same image to both cards simultaneously in cameras that have that option but I'm just curious if there's any image difference between the two formats, all else being equal.
Thanks.

I can not imagine any reasonable reason for it to be so. It is all the same digital signal, no difference in interpreting it in any manner. Digital is not to lose any info unless there is an actual error. Resolution does not apply. Otherwise, digital checks (CRC Checksum whatever...) would not be possible.

The 1s and 0s of the digital file will be the same no matter it is saved to an SD, CF, or hard drive.

CanonCameraFan wrote in post #17666748
I can not imagine any reasonable reason for it to be so. It is all the same digital signal, no difference in interpreting it in any manner. Digital is not to lose any info unless there is an actual error. Resolution does not apply. Otherwise, digital checks (CRC Checksum whatever...) would not be possible.

You mean those $200 3' HDMI cables aren't any better than my $2 Monoprice ones?

AFAIK SD and CF store digital information and HDMI transports digital information.
And yes, if you try both cables on my television set I would not see the difference.

Depends on how well made the cables are. You can experience differences between cables if one cable isn't well shielded against interference, if the contacts aren't reliable, or if the one cable's more vulnerable to bending than the other. Whether you'd see/hear this through an analog (eyes/ears) interface is another matter. But think about a new set of headphones vs. one that you've been banging around for a while.

Quack Me Up wrote in post #17666687
Sorry if this has been answered before but I was wondering if there has ever been any testing done to see if there any difference in image quality when an identical image is saved to and SD and a CF card? I'm not talking about saving the same image to both cards simultaneously in cameras that have that option but I'm just curious if there's any image difference between the two formats, all else being equal.
Thanks.

i think the answers above are going to be confusing, cause they're not talking about the same mechanism. as jon and others alluded, there are differences in quality among transport systems that can cause small variances, but again, that's not relevant here.

but for your purposes, in the case of your camera saving a picture, the whole advantage of digital is that every copy is identical (vs something analog like film.) so, there will be 0 difference.

The format is not different between CF and SD. The format is either RAW or JPEG. There's on difference.

If a photo in the camera, (let us assume a four pixel camera, yeah absurd but useful for illustration purposes) the acquired four pixels of data are these

1. 11000011010101
   
2. 11000011011101
   
3. 11000011110101
   
4. 11000111010101
   

the camera sends that string of 'bits' of data, 8 bits at a time, to a CF card...
11000011 01010111 00001101 11011100 00111101 01110001 11010101

or the camera sends those same string of bits, ONE bit at a time, to an SD card...
1 1 0 0 0 0 1 1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0 1 1 1 0 1 1 1 0 0 0 0 1 1 1 1 0 1 0 1 1 1 0 0 0 1 1 1 0 1 0 1 0 1

Later, in your computer you can transfer data from a CF card to an SD card...
11000011 01010111 00001101 11011100 00111101 01110001 11010101,
1 1 0 0 0 0 1 1 0 1 0 1 0 1 1 1 0 0 0 0 1 1 0 1 1 1 0 1 1 1 0 0 0 0 1 1 1 1 0 1 0 1 1 1 0 0 0 1 1 1 0 1 0 1 0 1

or vice versa, but apart from how the bits are grouped (or not), it is the same string of bits.

Therefore there is ZERO implication on the 'image quality due to which device stores the photo within a camera, just as there is ZERO implication on the image quality caused by transferring the photos between SD and CF using the computer.

Thanks to all for the input. Very informative.

absolutely no difference in image quality. because the file is in digital form, not analog.

As to SD, the IOs are NOT one bit at a time, but 4 bits at a time. There are total of 4 IOs in SD card form factor.

Yeah i would agree it's just different methods of storage.

I think something must happen transferring between different media, because quite often an image looks great on my camera lcd display, but when I get back home and transfer it to my PC and look at it in Lightroom or whatever it's not sharp/out of focus and/or badly exposed - It must be the make of hard drive I have...