I am reading between the lines here, I am not 100% clear, but it sounds to me like the photos you are discussing are not currently in Lightroom, but are on the camera card. Is that correct?
If so, then the solution is simple. Import from the camera card directly to the external HD.
To do this, you connect the camera or put the card in a card reader, then in the Lightroom Import dialog box, click on Copy and then on the right hand side, you select the Destination to be somewhere on the external drive. That's it!
To answer your question directly, your workflow will work. It is possible to import images to any hard drive, internal or external, that is connected to your computer. It is also possible to put your catalog and your previews folder on the external hard drive.
Thank you Dj and Jim for your prompt reply!
To clear some confusion--my photos are currently NOT in Lightroom. In fact, my photos are on the same external drive, but I have not pointed Lightroom to catalog that external drive (yet).
I want to point Lightroom on my internal drive to catalog photos on my external drive. I am assuming Lightroom will build the catalog on my internal drive and create low quality previews.
By telling Lightroom to point to the external drive for my negative pictures, I am freeing any space that would have been taken up on my internal drive.
My confusion and concern is the following:
1. If I tell Lightroom to point to the external drive to create a catalog on my internal drive, will that create a master copy, or copy, of the photos on my internal drive? I am trying to keep all large photo files off my internal.
I might be running in circles...!
No, that will not create a copy of the file on your internal hard drive. The import process in Lightroom is simply one of showing Lightroom where your images are located. The images will remain on the external hard drive. If internal hard drive space is a concern, you can also put your catalog and your previews folder on the external hard drive. Also, when you import new images using the Lightroom import dialog, you can choose the external hard drive as the destination. Alternatively, you can copy the images to the external hard drive as you described in your original post and then import them. Either way works.
Is there any benefit of having your catalog on your internal driving pointing to your external drive rather than having your catalog on your external drive?
I am thinking I want the catalog on my internal drive in case both reasons:
a) If I ever need to swap external drives in the future (2+ years or so).
b) By changing the point to location from my catalog on my internal drive to the new external drive would be a simpler move rather than moving everything over?
I don't think either of these is a reason for or against catalog on internal or external drive.
The only reason I know of to put the catalog on the internal drive is that catalogs should go on your fastest disk, which is usually the internal drive. Which is a pretty good reason, although people do put catalogs on the external drive.
Thank you dj!