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Forum: Digital Processing, Software, and Printing 11-19-2020, 03:35 AM  
Google shows how easy it is for software to remove watermarks from photos
Posted By TonyW
Replies: 33
Views: 2,526
EXIF and XMP data can easily be removed. In Photoshop for instance the Save for Web option with the Metadata set to None will do this.

Legitimate reasons for doing this may include reducing file size, removing sensitive information etc.
Forum: Pentax Medium Format 11-11-2020, 04:47 AM  
645D Which Flash to use for TTL
Posted By TonyW
Replies: 8
Views: 432
Yes the Pentax flash units that support P-TTL listed here
Forum: Digital Processing, Software, and Printing 11-03-2020, 08:27 AM  
X-Rite profiles for K-1ii
Posted By TonyW
Replies: 3
Views: 442
I agree with both Peter and Steve.


Should you feel the need for a colour profile that more accurately portrays your camera / lens system then you will need to make your own with the aid of X -Rite Colourchecker Passport X-Rite: MSCCPP-B : ColorChecker Passport Photo 2.

Are you sure you are using the correct profile for your particular camera?
Forum: Do-It-Yourself 10-01-2020, 07:42 AM  
Automated Panoramas with Rows!
Posted By TonyW
Replies: 8
Views: 1,081
:D Very impressed of a job well done
Forum: Digital Processing, Software, and Printing 06-11-2020, 02:58 PM  
Megapixels vs Maximum Printing Size
Posted By TonyW
Replies: 33
Views: 2,429
No one has ever printed at 72 ppi (they may think they have!) on an inkjet because it will be upsampled to printers native resolution if you do not do it yourself. 72 dpi is a typical dot matrix printer resolution from many years ago

Upsampling yourself to 300 or 600 ppi is fine if you have Canon printer but is wrong for Epson as it will use 360 or 720 ppi. Doing it yourself to printers native resolution is better than letting print driver upsampled using less than stellar algorithms.

Placing no value on print resolution is absolutely fine. By the same token no value needs to be placed on lens quality/resolving power, diffraction or any other aberration as without treating image data correctly none of it matters as you will have discarded the benefits of good glass with poor printing

Happy with throwing away the benefits of quality equipment at the printing stage is ok by me if it suits the individual.

Take chances with your printing absolutely, and for that matter your photography, but do yourself a favour and at least understand where your printing may fall down
Forum: Digital Processing, Software, and Printing 06-09-2020, 02:43 AM  
Megapixels vs Maximum Printing Size
Posted By TonyW
Replies: 33
Views: 2,429
Unless your printer cannot accept the medium there is no reason why you cannot print on canvas. Due to the generally coarse nature of the canvas there may not be much point exceeding half your printers declared PPI e.g. 150 or 180ppi.

Stand far enough away and the dots that form the image from the screen print will not be apparent.

The "proper distance" for viewing is often quoted as 1.5x - 2x the image diagonal:

10" x 8" image the viewing distance would be 19" - 25".

6" x 4" image the viewing distance would be 11" - 14"

The PPI (amount of pixels in the image data) is the important figure. That plus the printers native resolutions 360/720/1440 ppi (Epson). If your image data has been resolved high enough and has important detail then ideally you should send that data to the printer at one of those resolutions. It may be considered wasteful to print an image that has a ppi count of say 600 ppi at 360 ppi, as you should be looking at upsampling the data to 720 ppi before sending to the print driver.


Short answer yes :lol:


Bear in mind there are two resolutions that a printer deals with. The first is the PPI (pixels per inch) which is the printers native resolution related directly to the number of nozzles in the print head. To generalise a professional Epson printer will have a print head with 360 nozzles per inch, whereas a Canon or HP printer will have 300 nozzles per inch - note that some may have half 150 or 180 nozzles per inch. They will also have a finer resolution of 720 or 600 ppi and possibly one other of 1440 or 1200 ppi. These other ppi resolutions are achieved by a very fine stepping of the motor moving the paper over the print roller.
The second is the the DPI (droplets or dots per inch) this is a measure of volume of ink laid down on the paper and will normally be a multiple of the nozzle count of the print head. Quite often print drivers quote print quality such as Draft, Standard and High rather than actual DPI figures

---------- Post added 06-09-20 at 02:55 AM ----------

I posted some printed images as a quick and dirty example of printing resolutions here What PPI to send to printer for best IQ - PentaxForums.com


This to give some ideas of the difference that you may observe. In all cases view from far enough away and the resolution lost.
Forum: Digital Processing, Software, and Printing 06-05-2020, 03:25 PM  
Megapixels vs Maximum Printing Size
Posted By TonyW
Replies: 33
Views: 2,429
At 16 inches viewing using the rough formula above you would ideally be looking at around 200 ppi to give an impression of continuous tone.

Regardless of how many ppi you think you are using in actuality the printer will interpolate to its native resolution. If either 300 or 360 PPI
Forum: Digital Processing, Software, and Printing 06-05-2020, 10:37 AM  
Megapixels vs Maximum Printing Size
Posted By TonyW
Replies: 33
Views: 2,429
First off it is worth saying garbage data in garbage data out and no amount of messing with print resolution is going to help get a well resolved print. The only cure is to stand further back, far enough and many soft images will appear well resolved.


The human eye is certainly capable of being able to percieve much greater than 180 ppi (note not dpi this is a very different animal) it is entirely possible to percieve differences in a print made (with enough pixels!!) over 800 ppi. Again the detail must already be there in the image data as well as a sufficient pixel count.

You may want to quote viewing distances of 1.5 - 2x the print diagonal and assume that your prints will be viewed this way but what if the viewer is forced closer (narrow hall for display of a large print, viewer want to get closer than ideal to see more detail etc.).

There is a quick rough and ready way to calculate ideal PPI based on how close you are likely to want to view. Take the figure 3438 and divide by the viewing distance (in inches). EDIT: Note, these figures are for "average" viewing conditions. For "optimal lighting conditions" e.g. exhibition work, the figures could easily be doubled

10" viewing distance = 344 PPI
36" viewing distance = 96 PPI

But if you have enough pixel count then a 10" viewing distance may see improved resolution by printing at your printers native resolution e.g. 600 or 720 ppi (or possibly higher). In any case you should always aim to print at your printers native resolutions to get the most out of your print workflow e.g. Canon 300, 600, 1200 ppi with Epson 360, 720 ot 1440 ppi
Forum: Digital Processing, Software, and Printing 06-05-2020, 10:07 AM  
Printing for beginners - dark prints
Posted By TonyW
Replies: 18
Views: 1,224
IF the cause of dark prints is due to incorrect monitor brightness as opposed to poor viewing conditions of the print (i.e. print not illuminated) then one needs to lower the monitor brightness to achieve a match print to screen, if that is your requirement.

Too bright a monitor setting will actually lead you to see your image data much lighter than it actually is therefore the tendency would be to actually lower image brightness in processing
Forum: Digital Processing, Software, and Printing 06-04-2020, 01:57 PM  
Printing for beginners - dark prints
Posted By TonyW
Replies: 18
Views: 1,224
^^This most likely scenario for prints darker than monitor, but....

How are you judging them?

Do you illuminate the prints correctly if comparing next to screen?

Are they really too dark? How do they look when viewed in another room, outside, or ideally as they will be most often seen.
Forum: Digital Processing, Software, and Printing 05-27-2020, 07:57 AM  
Yet Anothe Printing Rant...
Posted By TonyW
Replies: 34
Views: 4,951
Have only just come across this thread so not read all the replies yet but... Bruce with respect there is really something wrong within your worfklow/system/ or other. So in an effort to throw some light on possible issues and highlight things that you really must consider and take seriously


Lightroom is probably the best simplest application to print through and much easier than Photoshop providing you do not have to undertake much specialised layer work. Even then there are some pros. that will still send there finished edits to print via Lightroom!

There may be other underlying issues for problems such as hardware or drivers or profiles

I do not think you should take for granted that your monitor calibration is anything but another possible weak link in your workflow that needs checking against known standards and for drift over time. There is a hint in the thread later on that you may have an issue






QuoteQuote:

1) If I was using my printer for A4 work last time it was used (even just printing word documents or something), then even despite telling LR and Windows that the paper is now A3 and all that other stuff (select correct photo-paper etc), hit Apply/OK, verify etc... it will still do one print run of the previous paper size despite given new parameters! Every. Single. Time. And it can be vice versa, if last time the printer was doing A3 work and now you have changed things to being A4, it will be a stuff up first go :mad:
On the second run, despite not touching a single setting it will print properly based on what you previously originally selected... :/
So the first image on any run is ruined, always, it's simply stuck in whatever mode it used previously and wants one more go on that despite what you tell it (windows) and LR... Waste of ink and photo-paper. A3+ is $6AUD a go... :mad: Totally unacceptable bug, and if it's not a bug then someone PLEASE enlighten me. It gets worse.



This is definitely abnormal for any printing application and is not IMHO either Windows or LR specific. It could be a printer driver issue or a caching issue (not purged after printing) but without knowing printer details and driver I would not like to say. Have you considered removing the driver rebooting Windows then reinstalling?





QuoteQuote:



2) In LR, bottom right of Print Module, you will find two tabs, 'Print' and 'Printer...'. If you click the 'Printer...' button it will launch the Windows Explorer printer window, you can then click 'Properties' and gain access to the following tabs;

-Quick Setup

-Main

-Page Setup

-Maintenance

All valid places to go to ensure the print is as you want it.

But have you ever noticed that upon changing the settings and then clicking 'OK' it doesn't just apply those changes and take you back to LR... No no no no nooooo.... applying those changes and hitting OK actually activates a print!! :mad:

I'm not blooming ready to print you $$*@!$!&!! I still have other LR settings I want to tweak or check!

I seriously don't even understand the point of the 'Print' button in LR's Print Module, must be a Mac thing because Windows decides to do Print stuff anyway without you actually clicking anything that says 'Print'... :(



Ideally your printer should be set up prior to going to the Print module. The correcty place to do this is in the menu FIle > Page setup. Once you are in the Print module it is expected that you will want to print using the settings you made in the Page Setup menu. You will either want to print immediately or check print settings then leave as is or change a setting and print immediately by pressing OK. Should you not wish to print at this time just press the cancel button no changes will be made to print driverThis is certainly wrong and a strong indicator that your colour management isnt managing at all. This includes monitor profile and paper profile. Either hosed and you will get what I think you may be getting. First if your simulating ink and paper looks nothing like your paper base colour then you are off to a bad and incorrect start.


Two things at work here:
1. Monitor profile. If this is an accurate representation of how your monitor displays colours at a given time (and is actually enabled in Windows) then LR and PS will use this information to correct your screen display to enable a close match to your image data - as close as possible within gamut limitations of the monitor.

2. Simulating Ink and Paper can only work if you are using the correct profile for the paper and the same ink as the profile produced and that profile is a good profile


Without both of these correctly in place your cannot hope for a match print to screen. If the simulation does not change the paper white to the base colour of your paper with soft proof on, either warm or cold tones or anything in between then either your monitor profile or paper is hosed - or both.

Soft proofing is a strong and powerful feature of LR in particular and PS and will do what it promises on the tin.







QuoteQuote:

4) Print Adjustment (bottom of LR Print Module) (often necessary) has only Brightness and Contrast sliders, both of which when adjusted give no feedback at all! There is no reference at all! Example;

First run of the print with both Brightness and Contrast set to 0, "hmm... prints a little dark, could use some brightening."

Yes but how much? +5? 10? 20? 40? 80? With no reference it's a complete lottery!

More $$ down the drain because it's always the 2nd or 3rd try till you get a print that matches more closely your LR image under a favourable ambient light...



Print adjustment often necessary, is a good indicator of less than optimal monitor profile. That is one set too high or too low for editing environment you will compensate in editing by making prints either lighter or darker than you intend.
Solution 1. Make sure your monitor is calibrated at the correct luminance for your viewing / editing environment
Solution 2. Do not use this stupid feature it has no place in professional software and in its current incarnation is useless to most


Not sure what you mean by using Print Preview - where and how are you switching it on and what version of LR?
Your lovely magenta and green tints are typical examples of double profiling (magenta), that is you are using both print driver and Lightroom profiles combined, and no profiling (green), that is you have switched off profiling in both print driver and LR







QuoteQuote:

So we have x1 dud copy from the start which seems unavoidable, a x2 dud copy because the image will be too dark or too bright (no wait to tell), maybe the next print you get lucky, or maybe it will be print x4 till you get something that matches what you see on your monitor with a monitor calibrated for the environment you are working in...

Niiice... great waste of money. By the time you hand the print to the client you'll be lucky to see any decent profit margin.

There HAS to be a better way to print than through LR... Does Photoshop do it better?

BB



Your too dark and too bright prints are a result of incorrect calibration. A correct calibration of luminosity is when a print matches the monitor (soft proofing on) and that assumes that you are actually illuminating the print correctly
Forum: Digital Processing, Software, and Printing 02-10-2020, 05:01 AM  
Monitor Calibration Tool Recommendation
Posted By TonyW
Replies: 36
Views: 1,949
May be worth stating that it is quite possible to get perfectly satisfactory prints without even having heard the words colour management. Just shoot and enjoy sending your files to any old lab for printing. Use half a dozen labs and you are likely to get half a dozen result that do not actually match for colour or density one to another and pretty certain that none will actually match what you see on screen looking at an edited image in soft proofing with your print near to screen and properly illuminated.

IF you and your work demands a WYSIWYG with finished prints or others viewing your images within a colour managed environment then calbration and profiling are essential parts of the workflow

It is important that profiles are updated regularly to account for imperceptible changes of the monitor over its life. Regularly means really what you want it to mean. Every 2 weeks is fairly common, once a month OK,some calibrate every time they start to edit or at least when they have critical work.

Using the supplied software vs seeing better in another product is a bit of a 'Red Herring' as in many cases it is likely to be attributed to operator finger trouble, assuming there is nothing wrong with the equipment or editing environment (ambient light, screen reflections). To try and judge by eye alone if a screen is too warm or too cold is folly. The reason I say this is because a white point of D65 or D50 is an exact temperature and not subject to variation. As an aside 6500k and 5000k are not exact and can be variation.

The problem most experience with software calibration is that once the White Point etc have been specified the user is then faced with trying to manually adjust the monitors colour to match as closely as possible what the software asks for. This may be either by adjusting the monitor controls manually or via the graphic card driver.

A much better, more accurate method and one that I would not be without is the ability of a monitor to be hardware calibrated, directly adjusting the monitor LUT's (originally limited to Eizo and NEC pro monitors now seen on quite a few consumer units)

Hardware calibration is the method of adjusting color directly by adjusting the settings inside the monitor. With hardware calibration, the target color is not reproduced through the graphic card output where all or a certain combination of white point, gamma, and brightness are reduced.

How could they tell that any tone was off? They would need to be sitting next to your monitor with the print illuminated correctly to see exactly what you were seeing.






QuoteQuote:

The difference is my workflow was not studio work for a lipstick company where colour accuracy is paramount. I'm questioning;

How important is external calibration of a newly purchased photography geared monitor for the purpose of photography work that sits outside the realm of studio absolute colour accuracy?



Only important if you require a WYSIWYG system

A quick aside if you are looking for a new monitor and photo editing is the criteria and colour accuracy of any kind is importance then I strongly suggest that you look for a monitor capable of hardware calibration is a very wise choice. Additionally I would be looking at an X -Rite device ideally the slightly more expensive i1 Display Pro to go along with it. If looking to purchase used then steer clear of the Spyder 2's and 3's in particular, first due to the inablility to correctly profile a wide gamut monitor and due to their variability between units.
....
Absolutely if you require WYSIWYG

Well R255 G0 B0 is a different beast in each of your potential editing spaces, sRGB, Adobe RGB, ProPhoto RGB (these are all synthetic spaces not based on any real world device) so why is a colour managed workflow using specifics any different? Because White Point of D65 or D50 is exact and affects the whole screen colour regardless of your editing colour space. This is something that gets reported to your colour savvy application to make a display of R255 G0 B0 look as it should within the colour space

Absolutely NOT! It is up to your clients to view or not view your images as intended using a colour calibrated device. Best you can do is try and educate them on the differences they may observe on their output device. Some websites acutally provide a step ramp and advises what to look for in shadows and highlight and how you may need to adjust - this only of course deals with the luminence issue of screens to bright or dark. Colour of course somewhat different although if you have a neutral known value in the image may help.
Forum: Digital Processing, Software, and Printing 02-07-2020, 02:12 PM  
Adobe RGB controversial?
Posted By TonyW
Replies: 61
Views: 2,687
What will happen potentially is CHAOS and confusion :D.

Best case you are making a 'Voodoo move' if you are dropping an sRGB file into the much larger colour spaces of Adobe RGB or worse ProPhoto RGB - you now have the potential to stretch the data too much within the larger colour space and cause banding artifacts - there is no point in doing this, but...

If you are editing from raw then use Adobe RGB or better yet Prophoto RGB for your file manipulation and then convert to whatever your print lab asks for - ideally they will tell you to edit and apply a specific ICC paper profile to your image. Worst case they will insist on sRGB

Do not send a lab either an Adobe RGB file or Prophoto file if they are assuming sRGB (many seem to!) then you will get wrong colours.
Forum: Digital Processing, Software, and Printing 02-06-2020, 09:37 AM  
Adobe RGB controversial?
Posted By TonyW
Replies: 61
Views: 2,687
It is not possible for a JPEG to be out of gamut (OOG) unless you or your editor modifies it). A JPEG is a baked file either from camera or your editing of a raw or other image. Anything OOG has already been discarded to fit neatly (or not!) into the JPEG container limited to 8 bit. If you are seeing OOG then your image is exceeding the gamut of either monitor or your chosen output profile. The OOG warning in PS and LR is rather buggy and very old and gives no degree of warning just how far OOG you may be.


Adobe RGB has considerably larger gamut than sRGB in certain areas such as greens, blues, oranges etc - many of the colours found in nature. Looking at a 2d representation of colour spaces ommits a lot of info - view in 3D to get a better feel for differences (see attached sRGB sat inside Adobe RGB)

Photo Labs demanding sRGB are doing this for their own convenience rather than follow a colour managed workflow. Printing needs an ICC profile for the paper in use and as you say many can exceed the colour gamut of Adobe RGB

Adobe RGB was a happy accident by Adobe engineers. They were copying coordinates relating to SMPTE RGB colour space and a typo was made. They found even with the error the colour space had value
Forum: Digital Processing, Software, and Printing 02-05-2020, 08:08 AM  
Monitor Calibration Tool Recommendation
Posted By TonyW
Replies: 36
Views: 1,949
Bruce this is a known issue with some of the Datacolor products after the Windows 1903 updates middle of last year. They have published a suggested workaround including uninstall of the Spyder software a MS patch and if that does not work disabling of "DisplayEnhancementService".

Details contained in this doc:
Windows 10 May 2019 Update (Windows 10, Build 1903) Unable to Create and / or Activate an ICC Profile in - SpyderX, Spyder5 and Spyder4 - Powered by Kayako https://support.datacolor.com/index.php? Help Desk Software

Bruce, with respect I think you may be under some misapprehension regarding monitors and particularly colour management and why we would want to calibrate a monitor.

I would say that no monitors right out of the box have colours bang on - how could they, as you have not defined your calibration points yet. Similarly turning brightness down or up needs to be calibrated for your ambient light editing conditions. This is not a matter of colour space sRGB or Adobe RGB they are merely colour gamuts which your monitor may be capable of displaying all or a percentage of.

If you are calibrating and profiling a monitor then by definition you are aiming for colour accuracy and far better than good enough, as this will just not do and has no place in a colour managed system.

So the first question is why would we want to calibrate a monitor? One answers may be so that we can be sure that others viewing our images on screen (with calibrated monitors of course!) will be seeing what we are seeing on our monitors within a colour savvy application regardless of system differences. Another answer, perhaps more important is so that we see our data exactly as it is and how it will print to paper via soft proofing facilities in our software.

Basically there are two parts to the calibration process. First we need to set our target/aim points which may be similar to White Point D65, Gamma 2.2, Contrast *, Luminence 80 - 160 cd/m2. Once we have these set and start the process then the application will measure how close we get to these points. The second part of the calibration process is the recording of these reading differences against our target points in the monitor profile that it produced.

It is with this accurate profile in place that colour savvy application e.g. Photoshop and Lightroom can adjust the display to take into account monitor differences (between aim points and actual) and therefore show an accurate representation of our image data on screen within the limitations of the monitors available gamut. Without this we could be editing an image to correct for a cold cast that is not in the actual image data which when viewed on another calibrated system may appear too warm both on screen and on paper. Similarly luminence too high and prints likely to be too dark or vice versa luminence too low and prints likely to be to light, because we have tried to compensate in editing for something that is non existing in the image data
Forum: Pentax K-3 02-04-2020, 05:30 AM  
Manual white balance test card for K-3
Posted By TonyW
Replies: 3
Views: 1,234
As long as the white balance card is accurate in equal RGB it should not really matter if it is light or mid grey. Be aware that some 18% grey cards are not actually neutral (they do not need to be as they are designed for exposure estimation). Note: I have not looked at 18% reflective cards other than those produced by Kodak which do exhibit colour variation, my own being towards the warm side of neutral

See attached. Left to right Kodak Gray Card, X- Rite Colour Checker Passport, Lastolite 12% Ezybalance. The X Rite passport also has a white balance and grey card built in. Using white balance on the Kodak card produces too blue an image, but really only a small difference that can easily be accounted for if needed
Forum: Flashes, Lighting, and Studio 01-11-2020, 04:40 PM  
Sekonic L478D have I got it right?
Posted By TonyW
Replies: 12
Views: 856
Precise colour rendition is not part of the profiling process with Sekonic meters and DTS software - the software and for that matter the meter does not understand colour, only luminance values can be measured by the meter and those values interpreted by the DTS software to produce a meter profile

It is also important to understand that you cannot profile your camera with the Sekonic meters. What you are doing with the DTS software is programming the Sekonic meter by supplying a profile that has recorded how the camera system responds and records light hitting the sensor.
Forum: Flashes, Lighting, and Studio 01-11-2020, 01:18 PM  
Sekonic L478D have I got it right?
Posted By TonyW
Replies: 12
Views: 856
I use the L758DR which is an earlier 1degree spot or incident meter. The DTS software allows you to calibrate the meter exactly (1/10th stop) to the way your camera system responds to light and save a camera profile (or several) to the meter. To achieve this there are a few ways including purchasing the very expensive (for what it is !) Sekonic exposure target or use either the Macbeth Colour Checker target or the X-Rite Colour Checker Passport (my preference).

Roughly the process of profiling the meter to the camera is:

Take a series of exposures as recommended by the software (a simple three shot or a mor accurate 5 shot) varying exposure as instructed.
Import the shots into the DTS software and run the process
Set clipping points and warnings as required.
Then attach meter to computer and download profiles direct to meter.

For more information about the practicalities seek out tutorials by Joe Brady e.g.:















You Tube




I think that most camera systems meter calibration point is between 12 - 13%. But as matrix and centre weighted metering is weighted towards manufacturers preferences and algorithms applied to interpret these preferences then actual figures may vary according to mode. Spot reading is the only way to be sure measuring and exact ROI.


An example would be that reading a highlight area and increasing exposure by +3EV to reach the clipping point would mean that the system calibrated to 12.5%. If the system was to be calibrated to 18% (I think unlikely!) then you would have about +2.47EV before your metered area reached clipping

Attached example of output of DTS software profiling the meter for spot reading showing a DR of 12 EV with clipping reached at around +3.5EV above meter indicated ROI
Forum: Digital Processing, Software, and Printing 01-04-2020, 02:51 PM  
.dcp file compatibility between Lightroom and RawTherapee?
Posted By TonyW
Replies: 11
Views: 1,771
You listed DCP (***.dcp) which is a Camera Profile and also asked about lens profiles which is a different beast LCP (***.lcp). It is possible to store in different places but the defaults (Windows) I believe are:


Camera Profiles
C:\ProgramData\Adobe\CameraRaw\CameraProfiles\Camera\Pentax 645Z\

Lens Profiles

C:\ProgramData\Adobe\CameraRaw\LensProfiles\1.0\Lens Manufacturer\

Also look here
C:\Users\YOUR USER NAME\AppData\Roaming\Adobe\CameraRaw\CameraProfiles
Forum: Digital Processing, Software, and Printing 01-03-2020, 10:13 AM  
Giving focus stacking a try
Posted By TonyW
Replies: 34
Views: 2,299
Why not try the demo of Zerene Stacker comparing the results from your best Combine Z stack

stacker [Zerene Stacker]
and

Helicon Focus

Helicon Focus - Helicon Soft

I have tried both and find them excellent.
Forum: Film Processing, Scanning, and Darkroom 07-18-2019, 09:06 AM  
Digitalizing negatives with Darktable
Posted By TonyW
Replies: 15
Views: 4,451
Not sure how much help as I do not use darktable, but correction should be reasonably easy (at least manually per image!). Effectively you are correcting per channel for both colour and contrast

Invert RGB curve first is a good start but then you will also need to correct individual channels or/and WB. The problem for producing a preset is really getting colour balance correct. You may be able to set up to sync images taken in the same light?

A quick play using LR (Darktable should be very similar?). Invert RGB composite (get blue/cyan image first) then adjust individual R, G and B channels to taste.


It is worth noting that you should really be cropping to the image area in camera rather than showing the surrounding as you have done here as this will make correction easier
Forum: Film Processing, Scanning, and Darkroom 07-02-2019, 06:20 AM  
What's happened to these negatives?
Posted By TonyW
Replies: 16
Views: 1,600
Photoshop Elements should be good enough for the job as would some of the free offerings such as Gimp which is Open Source editor
GIMP - GNU Image Manipulation Program

If you meant to type LR then this refers to Adobe Lightroom.
Forum: Film Processing, Scanning, and Darkroom 07-01-2019, 06:24 AM  
What's happened to these negatives?
Posted By TonyW
Replies: 16
Views: 1,600
Could be any of the points already mentioned or indeed a combination

Storage is another possible issue even in archival sleeves as temperature and humidity can have an adverse effect on long term storgage of film material.
Forum: General Photography 06-26-2019, 06:49 AM  
Print saturation.
Posted By TonyW
Replies: 20
Views: 993
Professional printers used for photographic prints generally fall into one of two catagories, dye types where dye is water based and pigment type where fine solids are held in suspension in a solution (not water). It used to be the case that dye printers capable of producing higher saturated prints than pigment. I suspect that this is not the case with recent pigment printers. Dye types gets absorbed into the paper surface whereas pigments tend sit on the surface

Colour gamut of many inkjet printers can exceed even Adobe RGB in certain areas, but is heavily dependent on print surface and substrate. The highest saturation, contrast and Dmax will be had on photo glossy materials and as already mentioned metallic and acrylic type printing may offer the maximum. Generally canvas type inkjet prints lose out in terms of contrast and potential resolving power to glossy surfaces

IF you have a wide gamut monitor AND you are soft proofing correctly on a calibrated monitor AND printing on a suitable substrate there is no reason that you should not get a print to screen match either spot on or very close. How close to the different media of oil or acryllic paints you can get I would not like to say but would suspect that for most purposes you should get quite close - assuming no special brighteners in the paint
Forum: Photographic Technique 06-11-2019, 08:48 AM  
Landscape Hyperfocal / landscape focus advices are wrong
Posted By TonyW
Replies: 38
Views: 2,868
Should you really need or wish to use a DoF calculator there are two that I can recommend:

Lumariver DoF (Android and iOS) - Has many customisation settings including airy disk and or pixel pitch and of course CoC. Anders Torger also has an excellent profile designer
Lumariver Depth of Field Calculator
And
True DoF. iOS only
Intro to TrueDoF-Pro

Then there is Harold Merklingers method not using hyperfocal
DoF Merklinger
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