Which is better and why - dv tape of memory cards?

[rudympohl]

Hi There:

Continuing with a previous discussion about which camcorder I should buy, I have another important question I would appreciate some feedback on: Which is better and why... DV tape or memory cards.

It seems to be the trend, as was mentioned in another post, that so many of the high-end prosumer and entry-level pro video cameras are no longer using digital tape but rather are designed to use memory cards. As I understand it (I'm still a newbie), when a camera saves it's video signal to a memory card it compresses the data into the mpeg2 and mpeg4 format. That's the way my $200 Sanyo camcorder works. Doesn't that mean that right off the bat you're losing image quality through the compression process, as opposed to digital tape where there is no compression? Then when importing into PE7 does the file decompress into an AVI file, and then have to be recmpressed to burn onto a DVD?

So what is happening with this treand in media for cameras (replacing tape with cards); are people giving up a certain amount image quality in return for certain benefits that come with using memory cards, such as convenience, cost etc?

I have found an older model of Sony camcorder that is very rugged and has great image quality and great in low light perfomrance (Sony DSR PD150) plus the price tag is right up my alley, but it uses mini-tape. Do you think I'm still OK getting a camera like this?

Thanks again for all the advice, sorry to be such a pest. (I'm glad you guys don't charge by the hour, or post - lol!)
Rudy

[tiny]

My understanding is that disk/memory uses higher compression than does tape. This means that the video footage will not be as fine, and editing will require a little processing power. Disk/memory is nice in that each shot is broken up, you can then delete shots you don't like. So for organization and getting video to the computer, it would be easier.

People aspiring to be filmers I believe still stick with tape, for the most part. The Canon HV series being very popular.

Those who want to just capture plenty of good memories and who are not overly anal about having the most clean picture will probably chose digital.

Hope that helps.

[Chuck Engels]

I think the loss of quality comes in when you have to uncompress and recompress the video.
There is definitely a greater potential for quality loss with memory than there is for tape.
Editing video that is so highly compressed is another challenge.

Due to the potential quality loss and the difficulty of editing the highly compressed video professionals are not yet headed down the same road. Our local TV stations have gone to High Definition but all of their cameras are still DVPRO and MiniDV.

From your other thread

I just went over to B&H and searched their "Prosumer" listings, and 10 out of 15 were still HDV

10 out of 15 being tape is a pretty good percentage as opposed to the consumer market where it is more like 2 out of 15.

You can't go wrong with tape that's all I'm sayin'

[Bob]

Which is better and why... DV tape or memory cards.

It depends on what you're going to do with it. There are pros and cons for each.

As I understand it (I'm still a newbie), when a camera saves it's video signal to a memory card it compresses the data into the mpeg2 and mpeg4 format. That's the way my $200 Sanyo camcorder works. Doesn't that mean that right off the bat you're losing image quality through the compression process, as opposed to digital tape where there is no compression? Then when importing into PE7 does the file decompress into an AVI file, and then have to be recmpressed to burn onto a DVD?

Digital tape is compressed also. Dv-avi is compressed 5:1, DVCPRO is a variant of DV but is still compressed, and HDV uses mpeg compression. Today's compression algorithms are much better than the older ones and you get approximately the same quality. The tradeoff is increased processing requirements. Importing into PE7 does not convert to dv-avi -- dv-avi, mpeg2 and avchd are all considered native formats in PE7. Notice the lack of the red line above the timeline. You will get a conversion and recompression when you export your DVD. I wouldn't worry about that. One difference between consumer, prosumer, and professional camcorders is the chroma sampling. Consumer units generally use 4:2:0, prosumer and professional generally support 4:2:2 which gives cleaner keys when doing green screen. Another consideration is editing. DV uses all i-frames and you can cut at any frame. MPEG variants generally don't use all i-frames and the presence of deltas makes cutting on a precise frame more difficult.

So what is happening with this treand in media for cameras (replacing tape with cards); are people giving up a certain amount image quality in return for certain benefits that come with using memory cards, such as convenience, cost etc?

Convenience is a major factor.

I have found an older model of Sony camcorder that is very rugged and has great image quality and great in low light perfomrance (Sony DSR PD150) plus the price tag is right up my alley, but it uses mini-tape. Do you think I'm still OK getting a camera like this?

Yes.

[Paul LS]

Because a video is more compressed does not necessarily mean it has lower quality. Different codecs compress with different efficiences but can still maintain quality. For example an AVCHD video at 19Mbps can well have better quality than a HDV video compressed at 25Mb/s.

However the more highly compressed videos do need more processor power to be able to edit them.

Another aspect is storage/archiving. I still prefer archiving on tape compared to discs or hard drives.

[rudympohl]

Hi Bob:

Thanks for the awesome explanation. You said

Today's compression algorithms are much better than the older ones and you get approximately the same quality. The tradeoff is increased processing requirements.

Do you mean that your computer has to be more powerful to edit mpeg files than avi files?

Also, can anyone point me to an online tutorial on all this stuff?

thanks Rudy

[Bobby]

One factor that I brought out in the other thread and got lost in the noise was the time it takes you to capture the video. With tape, your only option is to Play the tape, at real time speed. Thus it takes an hour to capture an hours worth of video on tape.

Memory cards transfer the data to the PC at your attachment speed. Normally this would be USB 2.0 and you should be able to transfer (capture) the video from the card at normal data processing speeds. It shouldn't take more than a few minutes to transfer a couple of gigabytes of data.

A factor perhaps not quite as important as quality, but if turnaround time for a job seems to be a factor (and it seems to be in jobs you have cited previously) this may be a more important factor.

[JohnnyO]

I also mentioned in the other thread that I was using the Panasonic DMC-ZS3, which captured high definition video in AVCHD-Lite. The quality is much better then my mini-DV camcorder. It is very convients to carry this one camera around for both photos and video.
I know it is not compatable with PRE7, but I am mention this because I am very pleased with the AVCHD quality.

[rudympohl]

Here's great article on editing MPEG4 files. http://www.videomaker.com/article/12242/

Note the good comment in section 3 about Premiere Elements and it's ability to handle MPEG4 editing! Great stuff!

Also, thanks agin for all the great input.

Rudy

[Bob D]

Thanks! That was a great article.

Bob D

[Paul LS]

Not sure if I can believe anything the author writes if he states:

Premiere Elements was one of the first on the scene to smoothly edit this format (MPEG4)

[Chuck Engels]

I was going to say "you can't believe everything you read on the internet" but decided to keep quite. Thanks for writing that post Paul, it really made me feel better about what I was thinking

[Paul LS]

[Bob D]

Yeah, I was thinking something similar also. Something along the lines of "if it only worked as well as it reads". But it was a godd read on the history (albeit brief) of MPEG-1,2,3 & 4.

Bob D

[rudympohl]

YAHOO I bought a camera!!!!

Thanks to everyone for all the very helpful input on my two recent posts regarding which camcorder to buy and which is better, dv tape or memory cards. Based on your feedback and my research on the net and weighing the pros and cons I made a decision last night and bought a gently used Sony DSR PD-150 for $1100 US - it came with a wide angle lens.

I decided that as my first serious camera I was going to try to buy a very good used camera rather than a new one, and despite it's limitations (no HD and no 16:9), really learn from the ground up how to shoot before spending some major money on an up-to-date camcorder once I get the hang of this.

I'm very excited and can hardly wait till it gets here (Rudy's like a kid at Christmas!!! LOL!)

Thanks again,
Rudy