JPEG Vs. TIFF Quality for Zenfolio?

[Richard Lane]

Thanks Mark, your input is greatly appreciated, as is everyones!


I chose MPIX, so that

[Kayaker72]

Hi Rich,


In the past I

[bob williams]

Rich, I have been using Zenfolio for about 18 months now----You definately want want to upload your shots in the highest res available. Zenfolio and Mpix will do the work after that. When you are logged on to your site and choose to share one of your photos, zenfolio will offer you several size options, so no need to down size of have smaller copies. Also, if you want to order a print, but the print doesn

[Richard Lane]

@Brant, Thanks for the link!


I guess you could say the website is under construction. I'm in the process of uploading images, adjusting the appearance and setting prices..., things like that. When I'm a little further along I'll post the link and I would love to get everyones feedback.


@Bob, Thank you very much, I appreciate it!





@Rick, I found out that Zenfolio downsizes their viewing images to 1550 x 960 as the max, you could even downsize this quality further. They claim that is done to protect the photographers images, and load the images faster, but now I'll have to explain to people that the images will look better when downloaded or printed. I'm not sure if that feature could be turned off.
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<div>Does anyone know if dpi (dots per inch) is the same as ppi (pixels per inch)?</div>
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<div>I'm uploading the images as JPEG original size, quality 12, and dpi=300, which comes out to approx. 10MB per image. The original RAW files are approx. 20MB, however since JPEG images are compressed and lossy, I assume that the 10MB is the highest quality for JPEGs from a 16MP Camera. If I'm making some incorrect assumptions, then hopefully someone will let me know.</div>





I'm putting a watermark on the uploaded images. For now, I'm just using the Zenfolio default setting "PROOF" Does anyone think that this is a bad idea, as it does block the image slightly, however the watermark is transparent and I lightened it up as well? Eventually I might upload my own watermark.


Also, does anyone know what a good "low-res size" for phones or social networking sites, the choices are 1MB, 3MB or I could set a custom Pixel x Pixel dimension, but I'm not sure which dimensions would work the best?


Do you guys and gals think I should charge a lower price for these low-res images, or just throw it in for free when they buy the high resolution image. In reality it takes the same amount of work to create the final image whether it's high-res or low-res.


I'm also working on some packages, apparently this website is very customizable.


If anyone else is interested, there is a setting in Zenfolio that gives the photographer final approval before purchase, so that you could re-upload a higher quality TIFF file prior to MPIX printing it. This is nice, because I've been editing these Surfing photos for the past 3 days and they're still not dialed in perfectly in my opinion, because I just had too many to edit (approx. 1500). However, if someone buys an image, then I will have an opportunity to just re-edit those images more meticulously.





Thanks,


Rich

[Kayaker72]

<div>Does anyone know if dpi (dots per inch) is the same as ppi (pixels per inch)?</div>

Hi Rich, I haven't dealt with this in years,so here is a link to wikipedia on the subject (http://en.wikipedia.org/wiki/Dots_per_inch). My understanding is that the terms are often swapped erroneously. DPIshould be yourprint resolution or output and ppi is your image resolution or input (when printing).So, if yourDPI matches your PPI you are printing one dot for every pixel in your image file, this would be equivalent to a "100%" image on a monitor. If you can print at 600 DPI, and your ratio of DPI to PPI is 1:1 then you also have 600 pixels represented per inch of your print (100%), or a lot of real detail in your printed image. When you print at ratios of DPI to PPI other than 1:1 you are either causing several pixels to be represented by a single dot, thus losing data, or having multiple dots representing a single pixel, essentially creating "fake" data in your image.


I hope that helps,


Brant

[Daniel Browning]

I was wondering if anyone knows the best quality to post pictures on Zenfolio.com for large prints.

Well, TIFF is best quality, but the difference is so minute under most circumstances that it's not worth the extra time. Compared to the highest quality JPEG, the only possible difference you could see is slightly higher detail/contrast in high frequency chroma detail (e.g. red feathers the size of one pixel). For most purposes, even the highest quality JPEG settings is overkill; more middle-of-the-road settings give "good enough" results.

Sometimes my images are cropped mildly.

For any given file size, compression is better than cropping, unless the software is braindamaged somewhere (e.g. uses a point-sampling resize).

If I use TIFF, should I use 8bit or 16bit?

I don't know of any printing services that can benefit from 16-bit files (certainly not MPIX); they would convert to 8-bit anyway.

[Richard Lane]

Thanks Brant and Daniel!


I uploaded the highest quality for JPEG, called Original Size JPEG and I was surprised to see that it uses the 22MB RAW file from the 1D-MKIV and then I end up with a 10MB JPEG file.


Does that mean that RAW to JPEG lossy compression is approximately 2 to 1 at is highest quality?


Thanks,


Rich

[DavidEccleston]

You

[Daniel Browning]

Does that mean that RAW to JPEG lossy compression is approximately 2 to 1 at is highest quality?

That's one way to think of it. Personally, I see it as more of a 9 to 1, and I'll explain why:


* Uncompressed 14-bit raw in the camera (27 MB)


* Lossless CR2 compression (like ZIP) in the camera (20-24 MB, depending on the scene)


* Raw file is decompressed and demosaiced to 16-bits in the raw converter (91 MB)


* Converted to JPEG (10 MB in your case).


So the JPEG doesn't really know that your image originally came from a 22 MB raw file -- all it knows about is the 91 MB image that is in your raw converter (e.g. DPP). It has to do the work of compressing 91 MB to 10 MB, so I see it as 9:1.

[Richard Lane]

David and Daniel, thank you very much for the explanation!





Rich