Thumbnail database size

[paulgul]

After some thought I have decided to give PS a try (already a idimager user). As a test I have just imported a series of folders that contain jpg's, the total size of the folders is just over 4Gb. I'm rather surprised to see the thumbnail database size is practically the same at just over 4Gb, this seems rather large, have I missed something, is there an option to save thumbnails at a reduced quality to save space.
I tried the same group of folders with ACDSee6 and the total database size (including thumbnails) is around 0.6Gb.
Anyone else noticed this?
Paul

[Lars]

After some thought I have decided to give PS a try (already a idimager user). As a test I have just imported a series of folders that contain jpg's, the total size of the folders is just over 4Gb. I'm rather surprised to see the thumbnail database size is practically the same at just over 4Gb, this seems rather large, have I missed something, is there an option to save thumbnails at a reduced quality to save space.
I tried the same group of folders with ACDSee6 and the total database size (including thumbnails) is around 0.6Gb.
Anyone else noticed this?
Paul

PS also stores previews which of course takes up a lot more space than the thumbnails alone

[paulgul]

Are these previews optional? if so how do I prevent them or turn them off.

[Mike Buckley]

Are these previews optional?

Yikes! I just realized that previews apparently are not optional. If I'm right about that, how does one review a RAW file or its embedded JPEG at 100% to critique sharpness?

[jstartin]

Are these previews optional?

Yikes! I just realized that previews apparently are not optional. If I'm right about that, how does one review a RAW file or its embedded JPEG at 100% to critique sharpness?

The stored previews are not optional. There is an options item to "load full size images" for the embedded and the full screen "previewer". For raw it requires waiting a bit while dcraw does its demosaicing stuff, naturally. The option persists for the "session", but defaults to off for each invocation of PSU. You can't get full size in the light table.

[Mike Buckley]

Thanks, Jim. I now remember seeing that capability being discussed and had completely forgotten about it. By the way, that sound you just heard was a big sigh of relief coming from me.

[paulgul]

So from what I understand then there is no way to reduce the database size. It just seems rather odd that the database is effectively doubling the amount of disk space required by the images. If this is so, then I'm afraid this program is not for me, I have around 120Gb of images to catalogue and will finish up requiring 240Gb of disk space.

[weidmic]

Paul,

you can change the size of the DB!
It's possible to change the preview size to a value between 640 and 1680 pixels in predefined steps.
After you have set the preview size, you need to build the thumbs and previews again. (don't know if it is necessary to compact the Thumbnail DB afterwards)
As bigger the preview size as bigger the DB!

HTH
Michael

[paulgul]

Paul,


It's possible to change the preview size to a value between 640 and 1680 pixels in predefined steps.

HTH
Michael

Must admit I didn't see that option
I've rebuilt the Db at 640px and the size has come down to 1.6Gb, I still consider this to be rather large for 4Gb worth of images.
Could someone explain why previews of jpg images are required when the original image is online, just seems a case of duplication.
Paul

[Mike Buckley]

Could someone explain why previews of jpg images are required when the original image is online, just seems a case of duplication.

The previews are most beneficial when reviewing RAW files, as displaying the preview is much faster than rendering the RAW data. You're right that previews are not particularly beneficial when viewing only online JPEGs, though my guess even then is that calling the preview from the database is faster than calling the physical image file, especially a full-size image, from the hard disk. It's the developer's choice to design the software so previews are built with no option not to build them.

[weidmic]

I've rebuilt the Db at 640px and the size has come down to 1.6Gb

Right, it sounds a lot... (maybe ) You didn't tell us how many pictures you have cataloged!
Did you compact the thumbs DB afterwards?

Cheers,
Michael

[paulgul]

A total of 13600 images. I thought it would be easier to create a new catalogue so I assume there was no need to compact.
But going back to my original post I used ACDSee to catalogue the same batch of images and its Db was only around 0.6Gb - It does save previews but I'm not sure what size, the program is set on auto size so guessing they are probably small.

[weidmic]

Paul,

I thought it would be easier to create a new catalogue so I assume there was no need to compact.

Absolutely! A new catalog should not need to be compacted...

Back the the amount of images:
14.000 images and only 4GB of space looks like the images are rather small.
If my calculations are correct your average image is around than 0.3 MB.

With very small images the advantage of having "previews" is very small...
But today, most pictures are much bigger than that - and as bigger the images in your catalog as bigger is the advantage of having previews saved in a database!

Hope you get the point of what I am trying to say.

Cheers,
Michael

[Mike Buckley]

as bigger the images in your catalog as bigger is the advantage of having previews saved in a database!

When we're referring only to original images that are JPEGs, I see no significant advantage to having previews stored in the database. I especially see no advantage that merits the extra storage space that is required and the time that is required to build the previews and store them.

[paulgul]

If my calculations are correct your average image is around than 0.3 MB.
Cheers,
Michael

Yes, you're correct about the size, these are not modern camera images, these were collected some years ago and arranged in "buckets" of around 4GB when backups were performed on dvd's
Perhaps the designers of the software will one day give users the option of not having previews - we live in hope