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 Replies: 72 / Views: 9,812 |
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Valued Member
Russian Federation
172 Posts |
Cool. Looks like expressionism movement art picture ))
Probably very small working distance with 10x objective and only stacking may help to improve it. Is it crop or whole frame btw?
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Valued Member
United States
441 Posts |
I cropped then resized to fit here. Working distance was very short. That would be the advantage to using the box cam that you use...greater working distance and easier to light.
Would I be able to get the mint mark to show close like my pic with the box cam and an M5 objective ?
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Valued Member
Russian Federation
172 Posts |
Andywoj, if your question to me then answer is no.
I have not M5 and even any coin with D mark )
Letter M (which I placed before) was this kind of mark here in my home)
It was not cropped and frame was about 3260px on width initially
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Valued Member
Russian Federation
172 Posts |
Don't know how small is your "D" and what resolution after crop of your pic was before posting to achieve 300KB, so hard to compare here.
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Valued Member
United States
441 Posts |
Justwalking.....from what I could research, mint marks on US coins are about .7-.9 mm high and .6-.7 mm wide. On my original picture, it was 6000x4000 prior to cropping. I cropped to 2463x2501; I probably should have squared it more in relation to the original size. Then, I resized to 1000x1015 and saved at a JPEG quality that would allow me to be at about 300k to post to this forum. Unfortunately, I'm somewhat dense when it comes to the physics of lenses/objectives regarding magnification and/or downsizing to prevent too much loss of resolution/sharpness. Not sure how much to crop/resize relative to original RAW image. |
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Valued Member
Russian Federation
172 Posts |
Then you can compare overall perfomance of our sutups.
2460 vs 3260 resolution and my M is little smaller (about 0.5mm in widht) so overall magnification of USB box was little higher in our shots.
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Pillar of the Community
United States
9395 Posts |
Quote:mint marks on US coins are about .7-.9 mm high and .6-.7 mm wide. If I measured right, the "D" on my 1956-D RPM cent is about 0.65mm tall, based on the following pic:  The T6s sensor is supposed to be 22.3mm by 14.9 mm (6000x4000 pixels). With a 10X Mitutoyo objective and a 200mm tube lens, the uncropped pic should cover 2.23mm by 1.49mm, if the magnification is accurate. (I'm not sure how much Zerene Stacker affects the magnification, since this 10X objective is not telecentric.) The posted pic was reduced from 6000x4000 to 600x400 before uploading here. |
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Pillar of the Community
 Canada
2784 Posts |
pepactonius that is simply incredible photo of that coin. totally excellent. that where I want to get to with my photos. outstanding
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Valued Member
Russian Federation
172 Posts |
So this double D was initially 1950px
We know that one pix in T6 is 22300/6000 = 3.71mkm
muutiply 3.71x1950=7238mkm or 7,238mm
If magnification of system is x10 then real double d on the coin is 0,723mm
on witdh.
It works if we know that magnification of overall system is exactly 10.
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Pillar of the Community
United States
9395 Posts |
Quote:
If magnification of system is x10 then real double d on the coin is 0,723mm on witdh. This is the 1956-D RPM-1 (based on some reference -- I'm not an RPM expert). The prior photo was of some other RPM (assuming it's a US cent), and the width is probably different. |
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Valued Member
Russian Federation
172 Posts |
In my M the witdh of letter is 500, so initially it was 500x3.26=1630
If my magnification was exacly x4 (not sure) but pixel size of sensor is less (1.4mkm) 1630x1.4=2.282 mm and letter is about 0.57mm (vary from coins) So we have comparable resolution with my magnification about #1093;4.
1630/0.57 ~ 1950/0.72
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Pillar of the Community
United States
9395 Posts |
The actual resolution from my setup is not really 371nm at 10x. The Mitutoyo 10X/0.28 is supposed to resolve about 1um or 1.1um, and the AA filter over the sensor reduced maximum resolution to about 3 pixels per line pair (on the USAF test chart). Stacking also seems to introduce problems, possibly caused by the metallic shine. Anyway, here's a 100% crop of a 1000x1000 pixel area of the sensor, about 0.37mm square:  |
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Valued Member
Russian Federation
172 Posts |
Pepactonius...
The resolution of overall systen can't be higher then of resolution of sensor. If the sensor have 3.71mkm minimum pixel size no matter how good is optic. Minimum separate detail on the picture will be 3.71 mkm
So mitutoyo outperform this sensor resolution.
3 pixels will be one pair line at witdh 11.13 mkm or 0,011mm or 90 lp/mm
So any lens higher then 90 lp/mm for whole frame give identicsl resolution for this sensor.
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Valued Member
Russian Federation
172 Posts |
For higer resolution need more reolution of the sensor. For IMX179 maximum optic resolution can be 238 lp/mm that's why for microscopy professional application camera have so small sensors. On my #1093;4 and IMX about 150 lp/mm looks like this It's a part of frame cover about 0.8mm of electronic chip  |
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Valued Member
Russian Federation
172 Posts |
Oops... 300.27Kb won't show on the board
I tryed to put less size .jpg but it won't also
Don't know why, sorry
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Replies: 72 / Views: 9,812 |
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Posted 01/17/2017 8:08 pm
