www.photomacrography.net :: View topic - Acceptable Sharpness?
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Acceptable Sharpness?
Goto page Previous  1, 2
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions
View previous topic :: View next topic  
Author Message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 18509
Location: Richland, Washington State, USA

PostPosted: Sun Jan 07, 2018 1:47 am    Post subject: Reply with quote

Deanimator wrote:
The full size image was resized -50%. ... I believe that the crop is from that image.

OK, good. So then it looks like your procedure for showing an "actual pixels" crop from some image is now working properly. Now all that's needed is to make that an actual pixels crop from a camera resolution image, and we'll all be comparing the same sort of oranges.

Quote:
The full size image was resized -50%. I thought the original would be too big to upload. I know it would be elsewhere.

Just because an image can be uploaded, doesn't mean that it should be uploaded. At some sites, you can upload a large image and the hosting site will both a) keep track of the original resolution image, and b) automatically generate resized copies that can be served out as appropriate. At photomacrography.net, that doesn't happen. Instead, the photomacrography.net forum software will accept large images but will immediately downsize them to 1024 pixels and throw away the originals.

So you have to ask yourself, do you really want to hand over control of the downsizing to some unknown piece of code? Or would you rather downsize it yourself so that you retain control over what gets served back to viewers?

For myself, the answer is simple: do the downsizing myself, and upload to the forum only images that are already 1024 pixels or smaller, with a file size of 300KB or shorter. That way the forum will serve back exactly what I uploaded.

The same idea is described like this in our Posting Guidelines:
Quote:
One caution: there is a feature that at first glance looks like it may be useful, but actually it is not. If the image on your PC exceeds the maximum image size for the forum, then the forum software will automatically and silently resize it for you. Don't be fooled! The forum software will indeed resize an overly large image, but the quality is very poor. It is much better to have the image sized properly before uploading.

But whichever way you go on that decision, when we ask for "actual pixels", we mean the same size pixels that the camera recorded.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Sun Jan 07, 2018 5:46 am    Post subject: Reply with quote

Well, here's the original image with no resizing, as well as a crop:


Back to top
View user's profile Send private message
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Mon Jan 08, 2018 3:09 am    Post subject: Reply with quote

The same subject with 20 micron steps.

Much more contrast in post.

Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7506
Location: Near London, UK

PostPosted: Mon Jan 08, 2018 4:12 am    Post subject: Reply with quote

You/we would need to see "actual pixels" again to compare, to see if the step size change made a difference.
Post in the highest jpg quality you can within the 300kB limit, these are much less.
If in photoshop you export "for web"/"for web and devices"/"(Legacy)" - names vary, it'll tell you the file size in advance. It only needs a representative section, such as you posted last time but as a separate image.

I thought the previous image didn't look super sharp, but then with this objective, diffraction is playing a part. It wouldn't be "pixel-sharp". The subject isn't the easiest for telling what detail might be there. Fine sandpaper, pencil-lead scrapings, butterfly wings, semiconductor wafers, laser-printed paper, and more have been tried! The last of those is certainly good. Address labels and bank statements with personal text (or barcode/dot patterns) can be sources.
_________________
Chris R
Back to top
View user's profile Send private message
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Mon Jan 08, 2018 6:34 am    Post subject: Reply with quote

ChrisR wrote:
You/we would need to see "actual pixels" again to compare, to see if the step size change made a difference.
Post in the highest jpg quality you can within the 300kB limit, these are much less.

Here's a < 1024 crop:

Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7506
Location: Near London, UK

PostPosted: Mon Jan 08, 2018 8:18 am    Post subject: Reply with quote

By comparison it looks sharpened - which I guess means it's sharper, assuming you didn't!
The one with the dot is the latest. I've increased the contrast of the earlier one to roughly match..

_________________
Chris R
Back to top
View user's profile Send private message
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Mon Jan 08, 2018 11:25 am    Post subject: Reply with quote

ChrisR wrote:
By comparison it looks sharpened - which I guess means it's sharper, assuming you didn't!
The one with the dot is the latest. I've increased the contrast of the earlier one to roughly match..

It was sharpened to the same degree as previous versions, but appears sharper. Apparently the smaller steps did make at least some difference.

Going from continuous light to flashes made the most difference.
Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 7506
Location: Near London, UK

PostPosted: Mon Jan 08, 2018 4:53 pm    Post subject: Reply with quote

I generally use a rather small step, partly for the edge of sharpness and partly for the odd flash failure - you can miss one frame without it noticing.
_________________
Chris R
Back to top
View user's profile Send private message
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Mon Jan 08, 2018 5:35 pm    Post subject: Reply with quote

Something with more texture, a piece of leather:

Original and cropped:



Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 18509
Location: Richland, Washington State, USA

PostPosted: Mon Jan 08, 2018 8:35 pm    Post subject: Reply with quote

Sharpened or unsharpened?

--Rik
Back to top
View user's profile Send private message Visit poster's website
Deanimator



Joined: 23 Oct 2012
Posts: 412
Location: Rocky River, Ohio, U.S.A.

PostPosted: Mon Jan 08, 2018 8:52 pm    Post subject: Reply with quote

rjlittlefield wrote:
Sharpened or unsharpened?

--Rik


Sharpened +75.

The combination of flash, reduced step size (20 microns) and increased sharpening seem to have made a lot of difference.

I've got a 300+ image stack of an emery board running in Zerene right now. I forgot to put my diffuser over it, so there's no telling how it'll come out.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Macro and Micro Technique and Technical Discussions All times are GMT - 7 Hours
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group