Plustek???

[koraks]

What I meant is: you would expect that Epson would have changed the CCD selection at some point in the 20 years between the 4990 and the v850, but for some reason, they haven't, and their newer scanners offer only marginally better optical performance than my old and beaten 4990. So it's not unheard of that a seemingly outdated CCD remains in regular use despite upgrades to other parts of the machine throughout consecutive models. All sings point towards Plustek doing exactly the same.

 

[brbo]

What I meant is: you would expect that Epson would have changed the CCD selection at some point in the 20 years between the 4990 and the v850, but for some reason, they haven't, and their newer scanners offer only marginally better optical performance than my old and beaten 4990. So it's not unheard of that a seemingly outdated CCD remains in regular use despite upgrades to other parts of the machine throughout consecutive models. All sings point towards Plustek doing exactly the same.

How do we know that Epson didn't change sensor from 4990 to V850?

What are all the signs pointing to Plustek using 3600dpi sensors? Where are the arguments that speak against the stated signs that Plustek is not using software interpolation at 7200dpi mode?

 

[koraks]

How do we know that Epson didn't change sensor from 4990 to V850?

Lack of increase in effective resolution. They may have changed the sensor, but they apparently never upgraded it. More like a sidegrade, if one happened in the first place, which I doubt.

What are all the signs pointing to Plustek using 3600dpi sensors?

Effective resolution as proven in tests.

Where are the arguments that speak against the stated signs that Plustek is not using software interpolation at 7200dpi mode?

(The various negations in that sentence make it hard to follow.)
What signs?

Anyway, how relevant is all this? I've done my share of second handed guessing whether or not a scanner manufacturer may have upgraded a sensor or an ADC. My academic interest in this particular issue seems to run out at this point.

 

[_T_]

If someone thinks they’re scans look better at 7200dpi it doesn’t much matter whether the resolution is being achieved through interpolation or if there’s any additional detail to be found in test targets.

And maybe they’re right; maybe on their unit there is some improvement to be had and to them it might be worth it to increase scan time and file size to get it. We wouldn’t be able to know ourselves without the particular unit and frame in hand to test.

 

[Helge]

If someone thinks they’re scans look better at 7200dpi it doesn’t much matter whether the resolution is being achieved through interpolation or if there’s any additional detail to be found in test targets.

And maybe they’re right; maybe on their unit there is some improvement to be had and to them it might be worth it to increase scan time and file size to get it. We wouldn’t be able to know ourselves without the particular unit and frame in hand to test.

The Plustek scanners consistently falls short of capturing the finest details and grain, even at various settings.
Often though, most frames on a roll doesn’t fully utilize the film's potential due to slight focus errors and camera shake, misleadingly suggesting a maximum resolution of 4000 dpi is good enough for everything.
However, when employing optimal taking/recording technique for certain frames, pushing the resolution higher does reveal a noticeable improvement in image clarity.

 

[brbo]

Lack of increase in effective resolution. They may have changed the sensor, but they apparently never upgraded it. More like a sidegrade, if one happened in the first place, which I doubt.

I've seen scans of resolution targets showing slightly more than 2800dpi on V850. The best I can do on my 4990 is slightly lower than 2000dpi. I consider that an increase. I'm not saying an increase is because of a sensor change/upgrade/sidegrade, though. I'm saying that sensors that can do 7000+dpi from 35mm film are nothing special.

Effective resolution as proven in tests.

Can you link to those tests? Every test that I've read said that for Plustek scanners scanning at the highest resolution is a must in order to reach highest effective resolution. Scanning at half the resolution lowers the effective resolution (not by much, but noticeably, like 20% in case of 7600). What is the explanation for this? Scanner can do an upscale on data from 2850dpi sensor that actually produces real detail?

What signs?

I hope you can understand that I don't feel like repeating my post #90, that was a already a provoked repeat of my post #85.

Anyway, how relevant is all this? I've done my share of second handed guessing whether or not a scanner manufacturer may have upgraded a sensor or an ADC. My academic interest in this particular issue seems to run out at this point.

No problem. Maybe someone else can come up with reasonable answers to my above questions. Now I just want to send my resolution target to Helge to scan it on this fascinating scanner...

 

[Brad Deputy]

I've owned an 8200ai almost 3 years, and scanned well over 10000 negatives and slides. It's holding up well but is getting slightly louder during scanning.

I've read some tests reveal the useful resolution near 4000-4200dpi. I scan everything at 3600. I once scanned a highly detailed TMAX 100 frame at 7200, and did notice some subtle detail improvement in areas of fine lines like fur on a cat. But, it takes easily twice as long to scan and each raw color TIFF is 400 MB. I determined it wasn't worth it for my use.

I understand the newer 8300 better utilizes USB 3.1 and offers improved scan times. If they do claim improved DMAX, then perhaps other optical changes were made, or better digital processing as was suggested.

 

[Ivo Stunga]

What are all the signs pointing to Plustek using 3600dpi sensors? Where are the arguments that speak against the stated signs that Plustek is not using software interpolation at 7200dpi mode?

Just a practical observation:

1) I've scanned a slide @7200 then downsampling it back to 3600 and processed it in Lightroom, then ordered a A2 size print from lab. This is a actually my default scanning process with Plustek.

2) I've scanned the same slide @7200 years later and have kept it this big, and processed in Lightroom. Then ordered a A2 print from a different lab.

Both prints are practically identical, meaning that the 7200 number is a joke from Plustek 7600i Ai.

Useful and easy to do scans nonetheles for a ~3600 machine.


3) I've ordered a A3 print from a physical slide and my tiff file at a lab. Plustek did better than lab and when questioned, lab admitted using flatbed. Tried another lab from my file and the results were better.

Plustek > Flatbed therefore.
And it can scan slide sandwiches too, meaning that it has hyperfocal thing going on or something (am quite illiterate about this).

 

[Helge]

Both prints are practically identical, meaning that the 7200 number is a joke from Plustek 7600i Ai.

Or your frame simply isn’t sharp enough.

 

[Ivo Stunga]

It's not just a single print, though. One was tripod and night with Delta 100, other being handheld Aviphot 200 at infrared, 1/30 with 50mm lens.
I could agree that 1/30 introduced some minor blur ans hence loss of micro details, but that night tripod shot had no business being printed that bad.

I try to be very meticulous about shutter speeds and motion blur, shooting slides. That massive enlargement isn't forgiving and you must be on top of your game.

 

[Alan Johnson]

FWIW here is my result for resolution:

Resolution of the Plustek 8100

I photographed a test chart using a Canon 50mm f1.8 at f8 lit by off camera flash, at the correct distance (50x focal length). Film was Ilford Delta 100, developed in Rodinal 1:50 . The chart was at the center of the frame. A negative of the chart was scanned at 7200 dpi in the Plustek 8100 and...

www.photrio.com

 

[brbo]

@Alan Johnson, thanks for contributing. Would it be still possible for you to scan that same negative at both 3600dpi and 7200dpi mode?

I can see a bit better resolution in vertical direction which would already indicate the combined resolution is more limited by the transport mechanism than sensor resolution. Still, comparing 3600dpi and 7200dpi should give us more clear answer whether Plusteks use sensors with more than 3000 photosites or not.

 

[250swb]

No problem. Maybe someone else can come up with reasonable answers to my above questions. Now I just want to send my resolution target to Helge to scan it on this fascinating scanner...

There can be no reasonable answers to unreasonable questions. You've fallen for a marketing trick of thinking optical resolution equals sensor resolving power. And it's a sleight of hand that Plustek have been using since day one, just as each 'new' scanner is in fact largely (or only) a newer version of Silverfast. This isn't a problem for people who understand the wording they use, you buy a scanner for what it is. As regards seeing a difference in scans at 7200dpi, yes there is a difference, but if you know what you are looking at it isn't an improvement, it's just more added pixels, and the extra scanning time is the software working out where to put them and not mining for better information from the negative.

 

[brbo]

There can be no reasonable answers to unreasonable questions. You've fallen for a marketing trick of thinking optical resolution equals sensor resolving power.

Can you point me to a post (that I wrote) from which you got the impression that I can't distinguish sensor resolution from optical and effective resolution?

and the extra scanning time is the software working out where to put them and not mining for better information from the negative.

Is that software routine for generating extra pixels running in scanner or is that implemented in driver/scanning software?

 

[Alan Johnson]

Scandig.com, the shop, changed their review since my test of 5 years ago [post 111] and it is now linked to here:

Filmscanner-Test Plustek OpticFilm 8100: Preiswertes Scannen von Dias und Kleinbild-Filmstreifen mit Filmhaltern mit SilverFast SE Plus 8

www.filmscanner.info

This gives a resolution figure of 3800 dpi, but only to be obtained by scanning at higher resolution 7200 dpi.

 

[Ivo Stunga]

but only to be obtained by scanning at higher resolution 7200 dpi.

Exactly what I read at the XP/Windows 7 times, so I always scan that way - although I don't know for sure if downsampling of interpolated image yields the better result, but I do it anyways and have scans like these: https://www.flickr.com/photos/ivo_stunga/

Takes time, but you can do it whilst watching a documentary, or a game, or having a chat...

 

[Alan Johnson]

IMO there is little incentive to improve the sensor in the Plustek 8100 as the resolution of fine detail is limited by the grain of the film. Only microfilm can improve fine detail much further, and the size of prints at 300 dpi would be of a size rarely used.

CD4-LC low contrast developer for scanning

Since my pile of silver gelatin prints got too big I have been storing my "prints" on Flickr , more recently on Flickr Pro which allows a maximum of 6144 pixels in the long direction. This gives about 85 lppm to the viewer. My film is 35mm CMS 20 II Pro scanned at 7200 [true~3600] setting on a...

www.photrio.com

 

[Helge]

IMO there is little incentive to improve the sensor in the Plustek 8100 as the resolution of fine detail is limited by the grain of the film. Only microfilm can improve fine detail much further, and the size of prints at 300 dpi would be of a size rarely used.

CD4-LC low contrast developer for scanning

Since my pile of silver gelatin prints got too big I have been storing my "prints" on Flickr , more recently on Flickr Pro which allows a maximum of 6144 pixels in the long direction. This gives about 85 lppm to the viewer. My film is 35mm CMS 20 II Pro scanned at 7200 [true~3600] setting on a...

www.photrio.com

It’s not!
How are we going to get this persistent misunderstanding eradicated‽
Any ideas?

Also, what is seen as fuzzy grain in a scan is often not. It’s a mix of grain aliasing and sensor noise creating interference patterns.

 

[Alan Johnson]

It’s not!
How are we going to get this persistent misunderstanding eradicated‽
Any ideas?

Also what seen as fuzzy grain in a scan is often not. It’s a mix of grain aliasing and sensor noise creating interference patterns.

What is the source of your information that this is a misunderstanding?

 

[snusmumriken]

What is the source of your information that this is a misunderstanding?

Surely the more recent thread here is source enough? The OP of that thread concluded from his negative scan that FP4+ had fuzzy grain. Others (including myself) pointed out that what appears to be coarse grain in scans from budget scanners is not matched in darkroom prints from the same negatives. It's evidently a common observation among those who do both, but perhaps impossible to demonstrate online. What is your reason to question it?

 

[brbo]

And it can scan slide sandwiches too, meaning that it has hyperfocal thing going on or something (am quite illiterate about this).

Plustek is notorious for not using autofocus in their scanners, so lenses need to have smaller aperture to cover larger dof. Small aperture necessarily means that lens resolution will be affected by diffraction. Lenses in consumer desktop 35mm pretty consistently test at about 3000dpi. Higher resolution is only achieved by oversampling, that is why every Plustek/PacificImage/Epson scanner produced today needs to scan at ridiculous mechanical and sensor resolution to get the best possible effective resolution. They could spend significantly more for better resolving lenses, but then they would also have to build the scanners to much higher tolerances, have better autofocusing mechanisms etc. to be able to exploit higher lens resolution.

Exactly what I read at the XP/Windows 7 times, so I always scan that way - although I don't know for sure if downsampling of interpolated image yields the better result, but I do it anyways and have scans like these:

It is not software interpolation. Check the prices of sensors and see how much sense would it make for Plustek to lie about the sensor in their 120 scanner being 10600dpi. Why would they pick the 5340dpi version over 10680dpi?
{moderator's deletion - please keep it civil}

 

[Alan Johnson]

Surely the more recent thread here is source enough? The OP of that thread concluded from his negative scan that FP4+ had fuzzy grain. Others (including myself) pointed out that what appears to be coarse grain in scans from budget scanners is not matched in darkroom prints from the same negatives. It's evidently a common observation among those who do both, but perhaps impossible to demonstrate online. What is your reason to question it?

That thread refers to the Epson 850 which resolves about 2400 lppm.
The Plustek 8100 resolves about 3800 lppm.
As illustrated in the link in post 117 there is a clear difference between scans of "ordinary" film and microfilm with the 8100.
Both the scans in post 117 came from files of about 30mb. Granted it should be possible to better show the grain structure as per a silver gelatin print with a lot more mb file size.
So I rephrase my claim to:
The resolution of fine detail [in scan files of about 30mb] is limited by the [apparent] grain of the film.

 

[Helge]

What is the source of your information that this is a misunderstanding?

I think it would be more interesting to find out what your source was?

Look, generally fast big grain film has lower resolution and slow fine grain emulsions higher resolution.
But grain is not a primitive like a pixel.

Magnetic tape is not limited in frequency response by tape hiss from magnetic grain either.

In fact some very fine grain film has a bit lower resolution than slightly coarser (TMX vs Delta & Ektar vs Portra 160).

 

[snusmumriken]

That thread refers to the Epson 850 which resolves about 2400 lppm.
The Plustek 8100 resolves about 3800 lppm.
As illustrated in the link in post 117 there is a clear difference between scans of "ordinary" film and microfilm with the 8100.
Both the scans in post 117 came from files of about 30mb. Granted it should be possible to better show the grain structure as per a silver gelatin print with a lot more mb file size.
So I rephrase my claim to:
The resolution of fine detail [in scan files of about 30mb] is limited by the [apparent] grain of the film.

I accept your point about your Plustek scanner not being the limiting factor. That scan from CMS 20 II Pro is astonishing.

But I'm left puzzling over the difference in apparent grain between scanning 'ordinary' film at that sort of resolution and projection enlargement. How does it arise?

BTW, it was funny to see the bow portholes of HMS Belfast in one of your photos. It reminded me of the way Amateur Photographer used to 'test' films and lenses by photographing a ship moored on the Embankment (HMS Wellington?) from the other side of the river. If you could count all the portholes, centre and edge of the image at maximum aperture, the lens/film was considered pretty good.

 

[Alan Johnson]

I accept your point about your Plustek scanner not being the limiting factor. That scan from CMS 20 II Pro is astonishing.

But I'm left puzzling over the difference in apparent grain between scanning 'ordinary' film at that sort of resolution and projection enlargement. How does it arise?

BTW, it was funny to see the bow portholes of HMS Belfast in one of your photos. It reminded me of the way Amateur Photographer used to 'test' films and lenses by photographing a ship moored on the Embankment (HMS Wellington?) from the other side of the river. If you could count all the portholes, centre and edge of the image at maximum aperture, the lens/film was considered pretty good.

Erwin Puts had some pics of what grain looks like at magnification and as Helge noted it would take a lot of pixels to effectively duplicate the larger magnifications:

basic facts about film

Projection magnification may be better than present day scanners at duplicating silver grains.

The ship Amateur Photographer used is still there, it was more readable in those days.