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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Navigation instruments from Paris, Maskelyne
From: Joel Jacobs
Date: 2004 Jul 21, 07:07 -0400
From: Joel Jacobs
Date: 2004 Jul 21, 07:07 -0400
The up graded edition of the Limited Edition of Photoshop 5.0 is available direct from Adobe for $99.00. It likely can be bought on ebay for much less. GO: http://www.adobe.com/products/photoshople/main.html I recommend it because the operations and use of its comprehensive tools are intuitive do not require a lot of learning. There are some pictures on this page which I think are quite nice. http://www.landandseacollection.com/id38.html They were taken with an Olympus D 400 rated at 1.3 MP, and edited with the LE 5.0 Edition of Photoshop. They were saved at 3 on the JPEG Options scale (histogram) which determines file size. Joel Jacobs ----- Original Message ----- From: "Peter Fogg"To: Sent: Tuesday, July 20, 2004 11:35 PM Subject: Re: Navigation instruments from Paris, Maskelyne > Photoshop is the most well known (and possibly the most demanding to use well) image management > software. Since computer screens only output at about 72 pixels per inch (they vary) there usually is no > reason to send pics for viewing on a monitor at a resolution any higher than this. In Photoshop, > choose 'image size' then save a copy of your pic at this resolution and at an appropriate size for viewing. > Then convert it to .jpg file format, but only after you have completed all other operations, as this step > loses image quality each time, the effects are accumulative. If your camera records in .jpg then convert to > another lossless format as the first step, then reconvert as the last. I wouldn't be surprised to learn that > there is software freely available that could do all this. Photoshop is really a professional application and is > quite expensive, although there are different versions available. > > "how to diminish them and not to degrade them too much" Photoshop certainly has wonderful tools. One of > the most useful is a histogram, called 'levels', which is like a statistical map of the amount of dark and light > tones. Almost every picture can be improved by playing with its 'levels'. But this is hardly scratching the > surface of what is possible with computer image manipulation. There is much information online. Its a big > subject. > > Quoting Jan Kalivoda : > > > Hello, Joel, > > > > thank you for your remark. I am fully aware of your troubles, but working > > only from internet cafes in Paris, I cannot help you and me now. I will be > > able to redress and republish my pictures only in August from Prague. > > > > Meanwhile, can you give me advice about software and modes that shall I use? > > I tried higher compression ratios for these JPG's, but the quality suffered. > > And as these pictures are not the best even uncompressed (it was a bit > > difficult to take them in an unsuitable room, deep behind the glass), I > > wonder, how to diminish them and not to degrade them too much. > > > > > > Thanks, Jan Kalivoda > > > > Joel Jacobs writes: > > > > > Hello Jan, > > > > > > Thank you for the invitation. But, the file sizes of you pictures average > > > about 2 Megs. For some of us they take too long to load even with > > broadband. > > > > > > Simple photo editing software would allow you to get the file size down to > > > 20 KB and still have good pictures. > > > > > > BTW, The first picture is still working on opening. > > > > > > I very interested in what you published, but haven't more time, > > > > > > Joel Jacobs > > > > > > > > > > > > > > > ----- Original Message ----- > > > From: "Jan Kalivoda" > > > To: > > > Sent: Monday, July 19, 2004 5:39 PM > > > Subject: Navigation instruments from Paris, Maskelyne > > > > > > > > >> Hello, > > >> > > >> if anybody wants, login to "http://www.xdrive.com" under the login > > >> "navigation@seznam.cz" (XDRIVE allows only valid e-mail addresses as > > > logins, > > >> as you probably know), password "celnav". > > >> > > >> You have 60 MB photos of some historical navigation instruments kept in > > > the > > >> Marine Museum in Paris (directory "Musee de la Marine") there. I tried to > > >> create the logical sequence of them from the nocturnal and the Jacob > > staff > > >> to repeating lunar circles. > > >> > > >> Of course, I am not a professional photographer and I didn't have the > > >> instruments available "au plain air". > > >> > > >> At the end of this week, I shall obtain some copies of Maskelyne's less > > >> known works printed in the 18th century. It would be interesting to chat > > >> about them a bit in the list. > > >> > > >> > > >> Jan Kalivoda > >