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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Testing prime focus digiscoping setups (1 Viewer)

Paul Corfield said:
As it's feather detail we are trying to resolve why not have a black box of a set dimension on the chart and stick a feather to it, not to exceed the edges of the box. The detail on a feather is much finer than we can print. To make the chart easier to focus on we could have some bigger, bolder black areas that are easier to see in the viewfinder. Just some random thoughts.

Paul.
Click to expand...

Neat idea Paul. However, I don't know how we would measure the resolution unless we ask a bird !

I'll try to do another target, starting from the Original ISO and making the resolution lines smaller. I'll post it for an opinion.
 
Paul you shot that feather from five feet so that is not a valid test,,:t:

Jules, I also did the test at the 20/25/30 and will be posting them today,, working on some of the granddaughters birthday party at present, you know about those priorities,, scope test work falls to the rear of the pack,,

do agree the focusing is something else at those distances,, really can see the need for a feather touch focuser,, even my study tripod would not hold the chart still at 10X live view trying to focus,, need a sturdy work bench to mount it all on,,

Derry
 
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Derry said:
Paul you shot that feather from five feet so that is not a valid test,,:t:

Derry
Click to expand...

LOL, that was from 10m with the 2X barlow. Here's the 100% crop. Just thought it would add to the visual aspect to the test rather than something to actually measure.

Paul.
 

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Version 3.0 of the target - tentative

Here is a tentative for V. 3.0 of the target.

It is similar to V. 2.0 except that I have reduced the vertical of the resolution lines set by 15%. I have kept the horizontal at 100%. I have used this new set to make the diagonal lines sets. It was more complicated for the lines set at the bottom - for those I have reduced both the horizontal and the vertical by 15% - not exact but close enough.

This is the best I can print with my Canon i960. My printer is unable to resolve if I reduce by 20%.

I have tested it full frame without a TC and with a 1.4 TC. In both cases, I can resolve at 20 maximum, but not much margin left.

You can get the file here:
http://julesgobeil.com/private/digiscoping%20target%20v3_0.jpg

Please try it and let me know what you think.

Regards
Jules
 
new chart looks good and agree we need to fill the frame and go with that reading,,

I have posted my findings below at 20,25 & 30m,,

at 200% on the original the finest line I can see clearly is..

20m = 16/17 on the angles and 16 on the hortizontal

25m = 15 on the angles and 14 on the horizontal

30m = 12/13 on the angle and 11 on the horizontal

was a warm, partly cloudy and windy day,,

Derry
 

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Good work Derry. Don't forget that it is NOT "the finest line I can see clearly" but the highest number where you can see white spaces BETWEEN ALL FIVE LINES.

Testing it this way, I suspect your results will be close to mine.

I'm happy that you also consider that filling the frame is the way to go.

Regards
Jules
 
I think the anti aliasing is really starting to suffer in the new test image, especially when compared to the original ISO 12233 chart. Is there a way to keep the original quality of the ISO 12233 chart even after repeated alterations?

I tried to print the new one but the jaggies are quite apparent.

Paul.
 
Paul Corfield said:
I think the anti aliasing is really starting to suffer in the new test image, especially when compared to the original ISO 12233 chart. Is there a way to keep the original quality of the ISO 12233 chart even after repeated alterations?

I tried to print the new one but the jaggies are quite apparent.

Paul.
Click to expand...

Humm... I don't seem to have that problem here - maybe I posted the wrong file. Let me see but it won't be until tonight.
 
my printed test chart (new one) is not as good on the line edges as the last one,, I'm still using the same paper,,



Jules, the lines I could see on the 20-25-30m photos are what I can count on my HD monitor viewing at 200%, 300% started distorting them,,

I sent David (dahyon) one of my first ISO photos to run his Imatest software on and he sent back several graphs and information on how well the Televue scope and Oly E3 did,, was nice to see some data on my set-up and how it compares to an original standard,, thanks David,,

Derry

" late edit,, was just looking at the chart at 100% in photoshop and it looks fine with all smooth edge lines but still does not print as well as the original charts,,"
 
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New target - V. 3.1

Here is a new target. I have done it using the original ISO 12233. Resolution at 20 maximum is as small as I can resolve very clearly with my printer. Paul and Derry, please try it and let me know what you think - unfortunately I cannot try it, it is raining again...

Other minor changes:
Resolution lines in all 4 corners
Size now 10" x 6.667" (254 x 169,33 mm) to give it a 4/3 (36x24) ratio.

Regards
Jules

http://julesgobeil.com/private/digiscoping%20target%20v3_1.jpg
 
Jules looks pretty good,,

I still need to go to Staples and pick up some better paper,, will do today and try a test shot before the sun goes down,, is 35.6C here today so will wait till it cools a tad,, humidity feels like 90%,, looks like the trees are even sweating,,


EDIT,, have the very good paper now and the chart will only print with smooth lines if printed in the good setting and in color on my printer,, tried several settings in B&W and ended up with jagged lines,, noticed the one I mentioned above was printed in the color setting,,????? the color printed is a dark purple (I'm a tad color blind though) but the 20 lines are resolved very good,,


Derry
 
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Derry said:
Jules looks pretty good,,

I still need to go to Staples and pick up some better paper,, will do today and try a test shot before the sun goes down,, is 35.6C here today so will wait till it cools a tad,, humidity feels like 90%,, looks like the trees are even sweating,,


EDIT,, have the very good paper now and the chart will only print with smooth lines if printed in the good setting and in color on my printer,, tried several settings in B&W and ended up with jagged lines,, noticed the one I mentioned above was printed in the color setting,,????? the color printed is a dark purple (I'm a tad color blind though) but the 20 lines are resolved very good,,


Derry
Click to expand...

The chart is in B/W. Yes you must print in the best setting and you must also tell the printer you have hi-res paper.
 
Jules,, tried a few more printer settings with various photo software and when best is used the lines remain jagged out of my HP 970 CXI,, agree ya would think best should be cleaner and clearer than normal,,

did select the new HP paper I purchased,, doubt if the purple color will hurt as the 20 lines are well resolved and will give it a try,,

sent ya a PM,,

Derry
 
Derry said:
Jules,, tried a few more printer settings with various photo software and when best is used the lines remain jagged out of my HP 970 CXI,, agree ya would think best should be cleaner and clearer than normal,,

did select the new HP paper I purchased,, doubt if the purple color will hurt as the 20 lines are well resolved and will give it a try,,

sent ya a PM,,

Derry
Click to expand...

Humm... you made me nervous. Just to make sure, I downloaded the file off the Net and printed it. It prints very sharp in pure B/W. Something must be wrong with your print settings. Unfortunately, I don't know anything about HP printers. Maybe someone else can help you.
 
I must admit I'm still having trouble with the chart too and I think it's still an issue with loss in detail compared to the original chart. I did a comparison by enlarging both charts. The image on the left is our chart and the image on the right is the original ISO 12233 chart. Our chart should look like the original and it should be possible if we work in a lossless format. I'm having to work on a painting deadline at the minute otherwise I could have a go myself but I should have some time later next week.

Paul.
 

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Paul Corfield said:
I must admit I'm still having trouble with the chart too and I think it's still an issue with loss in detail compared to the original chart. I did a comparison by enlarging both charts. The image on the left is our chart and the image on the right is the original ISO 12233 chart. Our chart should look like the original and it should be possible if we work in a lossless format. I'm having to work on a painting deadline at the minute otherwise I could have a go myself but I should have some time later next week.

Paul.
Click to expand...

Paul,

When I open the original I have and crop the "20 max" lines like you do, it does not come as sharp as your copy - see below. Is your file named: ISO_12233-reschart.pdf and what parameters do you use to open it ?
 

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The only way I have found so far to get the lines to come out as clear as the image I posted was to open the PDF in Adobe Reader and then I zoomed to 3200% and did a screen grab. That's not a practical way though to make a whole chart so I wonder if there is a way to convert the pdf to a format that wont lose the detail that is there. The detail is obviously present in the original to be able to zoom that much so it all gets lost in the conversion.

Paul.
 
Made some tests this afternoon with the target. I tried saving the lossless original (.TIF) to other lossless formats - .PNG and .PDF and is was no better that the .JPG available from my Web Site.

I also tried to make a new target using vectors in Corel Draw. This turns out better on the screen but the print is no better or worse than the last .JPG that I supplied.

I took a very quick macro picture of the V. 3.1 target, as printed with my Canon inkjet. Hanheld at 6". As you can see, 20 is easily resolved. I'm afraid it is the best I can do !

IMO, the limitation is with the printers and the monitors. If you crop at 500%, the lines become almost perfect. Comments and suggestions please !
 

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I think I've found a solution. On the link below is a basic Imatest chart and it's in SVG format. It has all the parts we need and can be edited with an SVG editor to form your own chart. There's also a link for a free SVG editor which I've been playing around with this morning. It should be pretty simple to come up with a new chart similar to what we have now and be in the highest quality possible.

To give everyone a fair chance at printing it should be made available in SVG format and say a TIFF format but not jpeg. With the free SVG editor there's no reason for anyone not being able to print at the highest quality possible on their printer an if needs be they can just use the TIFF.

Link with charts and useful info on editing, printing etc. http://www.imatest.com/docs/testcharts_SFR_SVG.html

Chart is here http://www.imatest.com/docs/images/small_chart_contrast_20.svg

Free SVG editor http://www.inkscape.org/

They have the SVG file available as a PDF too and it's loads bigger than the ISO12233 chart. I opened it in Photoshop at something like 1200 dpi and it came up very good, way better the the ISO12233 one, not as perfect as the SVG though.

Paul.
 
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