my first resolution measurement (1 Viewer)

[ronh]

You lose credibility around here if you don't first beat up on your expensive new binocular worse than anybody else. I'm glad to see I did it so convincingly. Make no mistake, this is love. I'd post more raves, but must first wait out the mandatory cooling-off period!
Ron

 

[mooreorless]

Hi Ron, I tired both the 8x32 and 8x42FL and really liked both of them. Now if I could get about $2000 for my 95 Ford truck.
Regards,Steve

 

[BobinKy]

Hi guys...

This is a great thread.

...Bob

 

[Dennis Mau]

Hi Steve,

those four best are in this order, although I would say that really indicates they are all very good. These results include readings barely achieved, but not suspected.

Fujinon FMT-SX 16x70 2.4arcsec
Nikon SE 12x50 2.56
Oberwerk Ultra 15x70 2.57
Nikon Action Extreme 12x50 2.7

edz

These are all porro-prisms aren't they? Hmm. Anybody have any resolution tests on roofs. Zeiss FL's or Nikon EDG's.

Dennis

 

[edz]

These are all porro-prisms aren't they? Hmm. Anybody have any resolution tests on roofs. Zeiss FL's or Nikon EDG's.

Dennis

as I said

more than 10 (out of 60) binoculars ranging from 7x50s to 15x70s that all could see resolution of 3.4 arcseconds down to 2.4 arcseconds. Only one was a roof.

Oberwerk 12x50 Sport rp 4.3
Leica Trinovid 10x42 rp 3.4
Nikon Monarch ATB10x42 rp 5.7
Pentax DCFHRII 10x42 rp 6.1
Zen Ray Summit 10x42 rp 3.8
Zen Ray ZEN ED2 8x43 rp 4.1
Celestron Regal 10x42 rp 3.6
Celestron Regal 8x42 rp 4.1
Bushnell Legend 8x42 rp 5.4
Garrett DCF 8x42 Apo rp 5.4

 

[mooreorless]

Here is more information for anybody that is interested in doing any of this. Of course it is Edz that posted this on Cloudy Nights and a big thank you to him.

http://www.cloudynights.com/photopost/showphoto.php?photo=5821

That is funny the resolution chart posted is the same one I have.
Regards,Steve

 

[mooreorless]

Hi Ron, A star test would show astigmatism and it would be possible to mount "tape" the USAF target at an angle. I am sure you know about star test etc. and am just posting this for other people that might not know. Your target sounds interesting, is there just the one size spacing? I have seen pictures of a target that Zeiss uses that sort of sounds like the one you used. BTW I bought my lens as a lens testing kit off Ebay, came with 7 lens to test camera lens. I don't have 7 left, I gave some away to some friends as far away as UK.
Regards,Steve

" BTW I bought my lens as a lens testing kit off Ebay, came with 7 lens to test camera lens. I don't have 7 left, I gave some away to some friends as far away as UK."

I never noticed my mistake here.

This should read. BTW I bought my USAF charts as a lens testing kit off Ebay, came with 7 USAF charts to test lens.

Steve

 

[ronh]

Steve,
Well, it took you long enough! Seven charts? All different?
Ron

 

[BobinKy]

Hey guys...

I don't know if this will help, but here is a link to a Wikipedia article on "1951 USAF resolution test chart." The Wikipedia article has some external links.

http://en.wikipedia.org/wiki/1951_USAF_resolution_test_chart

Here is the Google webpage for the search string "usaf test target 1951." Scroll down to jimdoty.com for the link to an online version that can be copied and printed.

http://www.google.com/search?hl=en&source=hp&q=usaf+test+target+1951&aq=0p&oq=USAF&aqi=g-p1g9

...Bob
Kentucky, USA

 

[mooreorless]

Hi Ron, That would be seven all the same charts and they look like the one in post #26 above. I always try to reread my posts and missed this one, and these things bug me. I am not the best at writing what I am thinking

Bob the bad thing about trying to print out these charts is that they might not be the right size and also you can not print small enough groups. The larger the group the further you have to measure distance.
Regards,Steve

 

[BobinKy]

Bob the bad thing about trying to print out these charts is that they might not be the right size and also you can not print small enough groups. The larger the group the further you have to measure distance.
Regards,Steve

Steve...

Yes, I understand about the issues with printing the USAF chart. What size is the chart you have? It appears to be something like 4" x 4".

Professionally printed USAF charts are available in various sizes on various surfaces, such as paper or glass. From the above google search, prices look like they start at $100 and move up. Some of the commercially printed USAF charts are printed on glass slides to test microscopes. Interesting.

You received a bargain when you received your chart with the 7 lenses.

As to be expected with any measure developed 50+ years ago, there appear to be critics of the USAF chart. However, it sure would be nice to have one to evaluate resolution.

I think I will try to copy one of the Internet files, resize to 4"x4" and print on my home laser printer. I will have to check the DPI (dots per inch) on my home printer. I think it is 1200 DPI, but I am not sure. Possibly an office supply store (Office Depot, Staples) has a printing service with more DPI. Kinkos might be another place to take the resized graphic for printing onto heavy card stock. If this works, multiple copies could be had at a reasonable price.

Anyway, if you do not mind, please post the size of your USAF chart.

...Bob
Kentucky, USA

 

[Surveyor]

Bob and others,

I have attached a couple of home made USAF 1951 charts in PDF format for non-scaled printing.

The printers I have tried so far can only get to about 4 lp/mm, group 2, element 1. Hope you have access to better ones.

Commercial photo printing techniques can do considerably better than this.

Best
Ron

PS: I have added a spread sheet I use to reduce data.

 

[BobinKy]

Bob and others,

I have attached a couple of home made USAF 1951 charts in PDF format for non-scaled printing.

The printers I have tried so far can only get to about 4 lp/mm, group 2, element 1. Hope you have access to better ones.

Commercial photo printing techniques can do considerably better than this.

Best
Ron

PS: I have added a spread sheet I use to reduce data.

Ron...

The 8.5x11 printed at my HP Laser Jet (home) and looks acceptable (I guess?). I also opened the spreadsheet. Thank you.

Do you mind giving us a few suggestions on how to use the chart and spread sheet?

...Bob
Kentucky, USA

 

[Surveyor]

Bob, first thing to do is check the printed USAF chart with a strong magnifier and see what the smallest group/element printed clearly. With out using auxiliary lens, this will define the closest distance that can be used.

With out getting into the whole discussion of boosted resolution and visual acuity and just describing the spreadsheet.

Mount or hold the optics as solidly as practical for the intended purpose, the steadier, and the better. Measure the distance from the objective to the target; accuracy of the measurement will be proportional to the result. If your distance is off 5% then the resolution figure will be off 5%, so mm level accuracy is not really required.

Read the target for the smallest resolvable group and element. Resolvable means the smallest element that you can determine the direction of all the lines of the element.

Enter the distance, in meters, in column B, enter the group in column C and the element number in column D. After pressing enter, the remaining columns in that row will calculate the dimensions of the element and angular resolutions. The last column is for use with the popular Pima 13A/ISO 12233 target.

Hope this helps.
Ron

PS: Forgot; at the top of the sheet, there is a cell for power. If set to 1 the calculations are for object space (real) resolution. If you enter the Bino or scopes power here, the output will be the image space (apparent or AFOV) resolution.

 

[edz]

Printing the chart on a printer and having it look acceptable is not the only thing you need to be concerned about. The lines have to be precisely sized to use the standard formulas provided with the chart. To use the standard formulas, in Ron's 8.5x11 chart above, it is extremely important that the chart be exactly sized. As a check, the three bars and two spaces in Group-2 Element 1 should measure exactly 10mmx10mm. The solid black square between the -2 and -1 (as well as group -2 element 2) should be ~9mmx9mm (exactly 8.9mm x 8.9mm).

I've never seen a commercial printer actually print a USAF chart to the precise size.

I printed Ron's 8.5x11 chart on a laserjet printer and got good image quality down to Group 1 Element 3 or 4. That's sufficient to test 60 power in an 80-mm Apo scope at a distance of 125 feet. Closer would require finer divisions on the chart. Binocular powers are well accomodated, even at much closer range, for instance 12x at 25 feet. Focusing at close distance changes binocular power, so testing at close range changes the power of the test, so too close a distance is not recommended.

However the entire chart was small by 6%.

edz

 

[Surveyor]

However the entire chart was small by 6%.

edz

Hi Ed,

There may well be a difference in our printers. I just checked a printed copy off my HP Laserjet here and group -2 element 1 is 10 mm and group -4 element 1 is 40 mm as close as I can measure them.

As Ed suggests, they need to be checked. Also be sure when printing the PDF that the "Page Scaling" is set to "None". On my printer if scaling is set to "Fit Printable Area" it prints at 96% (shows that figure in the bottom right corner).

Best
Ron

 

[ronh]

Thanks for the charts, Ron. I can deal with the size error easily enough.
Ronh

 

[edz]

Setting scaling to "none" does the job for correct size.. I'm printing to an HP laserjet 4350. image quality consistent down to group 0 element 4 or 5. quality OK down to group 1 element 3. between those lines and spaces are inconsistent in width.

edz

 

[pshute]

as I said

more than 10 (out of 60) binoculars ranging from 7x50s to 15x70s that all could see resolution of 3.4 arcseconds down to 2.4 arcseconds. Only one was a roof.

Oberwerk 12x50 Sport rp 4.3
Leica Trinovid 10x42 rp 3.4
Nikon Monarch ATB10x42 rp 5.7
Pentax DCFHRII 10x42 rp 6.1
Zen Ray Summit 10x42 rp 3.8
Zen Ray ZEN ED2 8x43 rp 4.1
Celestron Regal 10x42 rp 3.6
Celestron Regal 8x42 rp 4.1
Bushnell Legend 8x42 rp 5.4
Garrett DCF 8x42 Apo rp 5.4

What exactly do these figures mean? Are you saying that all but one of those are porros?

 

[mooreorless]

Edz is saying out of all the 60 binoculars that he has tested there are only about 10+ that could see 3.4 to 2.4 arcseconds with the use of a booster and out of that batch of binoculars he has only 1 roof prism that could see 3.4 arcseconds Leica Trinovid 10x42 all the rest are porro prism binoculars. The list of his that you have in your post are all roof prism binoculars with the boosted resolution next to the binocular. As you see the ones with excellent IMO boosted resolution are 4.1 through 3.4 4.3 is good too although it is the only 12x in this bunch and has 50mm objective lens.
Regards,Steve