Gianfranco47 wrote:
CF stands for compact flash and manual include also compact flash and SD cards too , manual is printed 5or 6 years ago , this card is new 2018 or 2019
That's true, but....
Look closely. It's not a "CF" card. It's a "CFast" card. That's a newer format type, derived from but not the same as nor backward compatible with CF. (Note: "CF" is a commonly used, but
unofficial abbreviation for "CompactFlash". Look at the memory cards themselves... they are always labelled "CompactFlash"... never just "CF". FYI, in addition to CFast, there's also "CFexpress", which is another new memory format that's *not* compatible with CF sockets. It *is* compatible with some XQD slots, if the camera can be updated to a specific firmware that allows CFexpress to be used in it.)
Not only do they not fit either of your cameras, CFast cards are extremely fast, quite large and VERY expensive. I bet you paid upwards of $400 for that one! Even if it did work in them, that card would be *massive* overkill for use in D800 or D4.
D4 has two slots.... XQD (ultra fast, too, similar to but incompatible with CFast) and CompactFlash.
D800 has two slots.... Compact Flash and SD.
You're wise to look for CompactFlash, in order to be able to use the card in both cameras.
With uncompressed, 14 bit RAW (NEF) files from D4 around 20MB each and from D800 roughly 75MB each... A 64GB card can hold around 850 D800 files or approx. 3200 D4 files (or a whole lot more JPEGs from those cameras). Based on that, I'd recommend you consider several smaller cards instead of one gigantic 256GB card. If anything happens to that, you might lose a week, a month or maybe more worth of images! Don't "put all your eggs in one basket"! Several smaller cards is safer... such as four 64GB cards. Choose a size that makes most sense for you... 16GB, 32GB, 64GB. Select cards big enough *in total* to handle one or two days shooting... multiple cards that you can swap out as needed. More smaller cards is better than fewer big cards.
A bonus, CompactFlash cards in more modest capacities will be a lot less expensive than that huge CFast card! Right now you can get 16GB CompactFlash cards for around $25 each, 32GB for around $30-$40, 64GB for $50-$65 apiece. For more money there are 128GB and 256GB CompactFlash available...But I'd say only use them at your own risk!
Here's a "compatibility list"...
https://www.bhphotovideo.com/c/products/Memory-Cards/ci/1097/N/4093113320?sort=PRICE_LOW_TO_HIGH&filters=fct_a_filter_by%3A03_INSTOCK%2Cfct_capacity_568%3A128gb%7C16gb%7C32gb%7C64gb%2Cfct_card-type_158%3Acompactflash