Re: Update to Epson scanning article: how to bypass all tonal adjustments
I don't understand yet if could be a routine workflow for scans or not
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
foen
I don't understand yet if could be a routine workflow for scans or not
It depends on if you want a routine scanning workflow or not, or better said when you want it or not.
IMHO when you want to make an extensive Photoshop edition/optimization for the image best is making a routine scanning workflow, taking all, and adjusting tonality and etc in Ps.
Also IMHO if one wants to just do some clicks in Lightroom then we can adjust the image with scanner software because we don't plan complex adjustments than may need all information in the negative.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
The Stouffer Transmission Step Wedge has 21 steps in "increments of .15". Each step is a half f/stop.
If my math is correct, 21 steps amounts to a density range of 10.5 f/stops. 2 exp(10.5) = 1448, which in log (10) terms is 3.16. If a scanner can clearly separate all steps on this target, it can handle a dMax of 3.16
When I tested the Epson scanner using Epson software a number of years back with my usual method of adjusting the histogram, I found that the scanner could separate "16 steps, or 8 stops, which is 256 levels, or in log 10 terms, 2.4".
Can either of the "raw" scans I made yesterday properly separate all 21 steps, or for that matter, significantly more than 16 steps ? By properly, I mean in a linear manner where each step is equidistant from the next.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Yes you are right, the 21 model is 1/2 stops steps, the 31 model is 1/3...
...but 21 steps are 20 difference, this is 10 stops, so 21 step is 1/(2^10) the 1st step, this is 1/1024. A range of near exactly 3.0D difference, the stouffer info says 3.05D (http://www.stouffer.net/Photo.htm), but the .05 may be because base density of the wedge.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
foen
I don't understand yet if could be a routine workflow for scans or not
This is just test, the negative has yet to be inverted. When it is, a tonal adjustment will occur. This adjustment will be dependant on the method used by software that performs this change.
Quote:
Originally Posted by
Ken Lee
Can either of the "raw" scans I made yesterday properly separate all 21 steps, or for that matter, significantly more than 16 steps ? By properly, I mean in a linear manner where each step is equidistant from the next.
The scanner can do at least 3.05D maybe it can even do 4D like the marketing suggests... :eek: But the tests seems to show how the noise seems to build up, and how a small adjustment to exposure can make a difference.
Quote:
Originally Posted by
Pere Casals
That may be true, ken made a 2.53X adjustment, which is probably about 1.3 stops (if the vuescan units are meaningful), "wiping" out the first three steps on the wedge.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Funny - My Epson V700 just died. I hadn't used it much lately until making these tests, but it now puts out a funny noise and the red lights flash.
No good deed goes unpunished I guess :rolleyes:
I took my old 4990 of the basement shelf and fired it up. Works fine. I wonder if it will cost more to repair the 700 than the price of a new unit.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
Ken Lee
Funny - My Epson V700 just died. I hadn't used it much lately until making these tests, but it now puts out a funny noise and the red lights flash.
.
there are 2 sliders to block the scanner for transport, one in the illuminator and another for the bed, check
both are in the right position
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Thanks Pere. I checked and reset those switches several times.
I was making test scans all day: at a certain point the machine just stopped working.
I presume that some part needs replacement.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Ken, I bet you got plenty of mileage from that pile of plastic. You shoot way more than I. I bought a V700 and not the higher models on your website recommendation and tutorials. I have been very happy with mine. It even has survived two moves. That surprised me.
The only good thing about a new one is that the LED does not need a warmup. Or maybe that's a bad thing on second thought. Warmup is good for many things.
I reserve my V700 for only LF negs. Prints I use a scanner app on iPhone.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
Ted Baker
This is just test, the negative has yet to be inverted. When it is, a tonal adjustment will occur. This adjustment will be dependant on the method used by software that performs this change.
Do we know what method the ColorNeg/ColorPerfect plugin uses as this to me seems to do a far better job at the inversion than Photoshop, just a shame about the clunky interface
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
Ken Lee
Funny - My Epson V700 just died. I hadn't used it much lately until making these tests, but it now puts out a funny noise and the red lights flash.
No good deed goes unpunished I guess :rolleyes:
This happened to my V800 3 weeks ago. According to Epson, the error was because it could not communicate with the drivers. I deleted the drivers (MAC) reinstalled them and its been ok since, still cannot work out if/why drivers would cause the error.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
IanBarber
Do we know what method the ColorNeg/ColorPerfect plugin uses as this to me seems to do a far better job at the inversion than Photoshop, just a shame about the clunky interface
The company published some of the maths behind their product. I used it as starting point for my own project, along with some stuff from Arri and Kodak. I think the Photoshop inversion is just (1-X) where x is normalised value of the negative scan, that is just a guess, but if it is poor then that is probably why...
Quote:
Originally Posted by
Ken Lee
I guess this means the VueScan scan is more linear. But what if we apply a slight correction curve to the Epson scan: will any differences become negligible ?
I went through each of the scans that ken posted, I first converted them to a gamma of 1, and measured each step. I can't seem to post the spreadsheet, they all show a reasonably linear response from the CCD, it is less linear towards the bottom of the scale. I think the vuescan exposure is clearly better, it gets you further away from the noise floor, and the response is more linear away from the bottom of the scale. Can you tell the difference in a real print? I don't know! I suspect maybe with colour, where poor accuracy in the highlights would result in colour casts.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
Ken Lee
I checked and reset those switches several times.
Quote:
Originally Posted by
IanBarber
the drivers
Yes Ian, you are right, first is downloading last drivers and reinstalling.
Anyway an abnormal noise may happen when stepper motors cannot move the carriage because it is blocked, perhaps if the scanner was operated while it was blocked it could happen than a wheel jumped a tooth or something like that, resulting in a missalignment. I would remove the bed glass and I'd inspect what happens, then I'd free mechanical links to see if a section of the mechanical chain of the drive is mechanically blocked, or perhaps some dry teflon lube can solve it. Because the noise, it may be a mechanical issue easier to DIY fix.
Quote:
Originally Posted by
Randy Moe
The only good thing about a new one is that the LED does not need a warmup.
Randy, you are right, V850/800 have same performance, avoiding the warmup is convenient, but IMHO there is another advantage, LED illuminators are very stable requiring little or no calibration overtime, if one wants the scanner calibrated. Lamps of the V700/750 (I guess) can change illumination a bit at the beiginning, then there is a more stable level during several thousands of hours, and by end of life of lamps again we have changes in the illuination's level and hue.
My V750 came with an IT8 calibration slide, the V850 came without it. Perhaps with saving the cost of the IT8 target they can fit the LEDs :), well, and sure today leds are cheaper...
Re: Update to Epson scanning article: how to bypass all tonal adjustments
The scanner makes the unpleasant sound as soon as the power switch is turned on. It's not a software issue as far as I know.
I guess I need to open it up and see if there's anything obviously wrong. I'm not particularly good at repairs.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Ken, sorry to hear about the V700. Not sure if this helpful, but I think you are on a mac platform. I recently installed High Sierra and it caused a problem communicating with a 4 year old Epson all-in-one printer/scanner. Normal wireless installation of the printer is no longer possible, and it needed to be installed using a fixed IP address. I now use this all-in-one device wirelessly using the fixed IP address. EpsonScan no longer functions using this connection method, and Apple ImageCapture is the only way to utilize the scanner for simple/everyday things.
I use my V750 with a USB cable. While on the surface this may seem apples and oranges, as mentioned above, the drivers and connectivity could be the issue. I would also add that any OS updates done recently can be problematic, if you are using mac. The recent update to High Sierra was also somewhat painful to install, after a very painful High Sierra installation.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
I don't think it's not a software problem. The scanner worked fine while I was doing tests. Then it just stopped working after no changes were made to anything. It can only be a mechanical or electronic failure.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
Ken Lee
It can only be a mechanical or electronic failure.
Just a thought...
There are two "zero position" sensors for homing, one is for the sensor carriage and the other is for the illuminator carriage, perhaps when "powering on" the scanner reaches the mechanical top without sensing the zero position, and thus trying to go beyond, so the stepper motor would make that noise because it could not rotate.
First try to see if the noise comes from the under bed drive or from the illuminator drive in the cover. Then locate the "end of travel" sensors that should tell the control electronics that a carriage its at home. The scanner uses those sensors to find a known starting position, from there it can count steps to place the sensor and illuminator in the wanted position. I don't know what kind of sensor is it, but for sure you have 2 there...
There several videos in youtube explaining V700/750 disassembly for cleaning https://www.youtube.com/watch?v=z7QkfM5TQ4A
Anyway if you find that a carriage tries to go beyond a mechanical end it would be worth to repair it, because probably parts to replace are simple.
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
IanBarber
Although it hasn't been mentioned from what I can see, has anyone actually done a scan with no adjustments of a stouffer wedge to see how many steps the scanner can actually read
I have done that with Stouffer 31 step wedge. Shows greater than 3.05D for Epson V850.
Post number 37 http://www.largeformatphotography.in...n-target/page4
Re: Update to Epson scanning article: how to bypass all tonal adjustments
Quote:
Originally Posted by
IanBarber
Do we know what method the ColorNeg/ColorPerfect plugin uses as this to me seems to do a far better job at the inversion than Photoshop, just a shame about the clunky interface
Obuse CP but don't know algorithm. It does however, do the best job I have seen so far.