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Forum: Digital Processing, Software, and Printing 1 Day Ago  
Printing resolution?
Posted By TonyW
Replies: 12
Views: 580
FWIW my thoughts on this:

An image file does not have a size only a pixel count in the x and y directions this applies to raw, JPEG, TIFF etc. So all files will have the same pixel count but the loss in quality associated with JPEG is down to the way the algorithms discard information (not pixels). My understanding is that colour information is first to be dropped then luminance as required by the amount of compression applied. TIFF will not generally drop any information in the most popular compression algorithms.

You can calculate ppi requirements quite easily with a very simple formula minimum ppi = 3438 / Viewing Distance. Assuming someone with 20/20 vision. So if we know that our print is going to be viewed ideally from 8" away then the minimum ppi calculation reveals a need for 430 ppi. Bear in mind however that these figures are for 'average' lighting conditions, high contrast optimal lighting these figures can easily be doubled

300 ppi is often touted as the resolution of the human eye hence the just as often stated that we do not need more than 300 ppi in print.

The human eye can under good conditions resolve objects slightly less than one arc minute (assuming 20/20 vision). At a distance of 10 inches 1 arc minute corresponds to 0.003 inch the inverse therefore equal 344. It takes at least two pixels to resolve something therefore we are looking at around 700 ppi as the eyes resolution Ė but the eye can actually do better than this!

So starting with a good image contain lots of detail you should be able to see the difference between prints with the image set to 150 ppi, 300 ppi and 600 ppi. Note these are standard resolution for most Canon/HP/Fuji printers. For Epson you would substitute 180 ppi, 360 ppi and 720 ppi. Ideally we would use these figures and upsample in our favourite image editor to ensure optimal IQ over just allowing the print driver to upsample generally using the poorer Nearest Neighbour resampling.

Apart from seeing the difference myself with actual prints many others have documented these facts on the net. May be worth trying for yourself with your particular printers?
Worth mentioning viewing distance. Stand far enough away from a print and you will not see the differences that higher ppi values bring. But most of us will tend to look quite closely at a print that interests us and if compared side by side detail will be revealed in the higher ppi version most of the time. Print surface will also have a bearing on resolving detail rougher / textured surfaces may only require half the ppi of gloss semi gloss.
Forum: Digital Processing, Software, and Printing 3 Days Ago  
Printing resolution?
Posted By TonyW
Replies: 12
Views: 580
Depends on your online printing service, their services and requirements for file submission, which should relate directly to the printer requirements.

For Canon/HP/Fuji you can expect a required standard resolution of 300 ppi and if native size above this 600 ppi will get the optimal quality assuming image is first rate and has the necessary IQ in the first place

Epson printers tend to use 360 and 720 ppi.

Whatever else happens in the print pipeline the print driver will resample your data to match its declared resolution 300/600 or 360/720. Using its own resampling algorithms which designed for speed, likely to be nearest neighbour.

You can use superior algorithms in applications such as PS and LR plus many others which may prove better in handling your image data

Typically in my experience many labs will use the lowest resolution when specifying file requirements. Nothing particularly wrong with this but if you have the native resolution and the subject matter contains strong lines diagonal and circular the higher resolutions may exhibit improvements and not leave IQ on the table.
Forum: Digital Processing, Software, and Printing 09-17-2018, 07:54 PM  
Viewing a photo with photoshop and faststone
Posted By TonyW
Replies: 7
Views: 406
It sounds like you are probably using the ACR defaults in CS6 when opening your images ie Adobe Standard. This is designed to give a pleasing neutral rendering to raw data from most cameras.

Adobe also provided settings that matched closely the camera presets mimicking the view you get on the camera LCD and when viewing JPEG.

You may wish to try altering ACR defaults to apply one of the camera profiles automatically when opening your raw files

This may be of interest

ACR Profiles
Forum: Troubleshooting and Beginner Help 09-16-2018, 09:41 AM  
Longevity for Eneloop batteries
Posted By TonyW
Replies: 24
Views: 824
They can certainly get quite warm and the fast drain could be down to age, but could also be coupled to the charger.

Perhaps you may wish to consider a better charger, one that allows for a charge discharge cycle- assuming that the Energiser charger is it of that type. It is possible that a full charge discharge cycle may rejuvenate them

I particularly like these from the Maha range
Chargers - 8-Cell Chargers - Maha Energy

Some basic Eneloop info
eneloop Technologies - Panasonic
Forum: Pentax Price Watch 09-04-2018, 12:24 PM  
Pentax 645 Auto Bellows, eBay.com
Posted By TonyW
Replies: 3
Views: 305
Hi Murray

Thank your for your kind offer have sent you a pm

Cheers
Tony
Forum: Pentax Price Watch 09-04-2018, 02:29 AM  
Pentax 645 Auto Bellows, eBay.com
Posted By TonyW
Replies: 3
Views: 305
Murray, Thank you for the heads up - just bought the item :D

I am interested in the PDF manual
Forum: General Photography 08-31-2018, 05:55 AM  
Displaying a Print at Home and its Lighting
Posted By TonyW
Replies: 32
Views: 1,008
I don't think that is the case now.

While general purpose LED may appear to be colder it really depends on how the quality and newer generations are very good with excellent light quality and longevity, Soraa and Yuji spring to mind immediately and they should be able to at least match 'old fashioned' lighting while giving benefits of lower running costs and running much cooler.

If you want halogen then currently the best option I believe will be Solux probably the 4700K. Relatively inexpensive solution but they run very hot
http://www.solux.net/cgi-bin/tlistore/colorproofkit.html
Forum: General Photography 08-13-2018, 08:45 AM  
Displaying a Print at Home and its Lighting
Posted By TonyW
Replies: 32
Views: 1,008
Great result and a bonus low cost solution :D
Forum: Pentax Medium Format 08-11-2018, 09:06 AM  
Problems using On1 Photo RAW with 645Z files
Posted By TonyW
Replies: 20
Views: 1,188
DNG does not rebuild raw data, it is merely a container to hold the raw data exactly as your camera puts out.

That container as I understand it is TIFF/EP format like many manufacturers proprietary raw formats.

Essentially a DNG file from your Pentcanikus is exactly the same data as PEF, CR2, NEF etc but in a format that other software can use (if your camer particular PEF format not supported) there are a few.

It also allows manufacturers to include specific information for their particular brand of editor, which may or may not be understood by others. DNG is native format for other camera marques including Leica and Hasselblad.
Forum: Pentax Medium Format 08-08-2018, 03:45 AM  
Problems using On1 Photo RAW with 645Z files
Posted By TonyW
Replies: 20
Views: 1,188
As it only occurs with .pef and then only in On1 product (assume .pef ok in all other raw editors?) then it really has to be their issue in the conversion process of 645z pef. Highly unlikely IMO to be graphic card related.

While Adobe came up with DNG it is not their proprietary format - all information relating to the format is published and in the public domain, therefore they do not control it. They also own TIFF format

Does the pink sky in the editor print as pink?

Does the pink sky stay pink if you convert image to TIFF or JPEG?
Forum: General Photography 08-05-2018, 01:30 AM  
Displaying a Print at Home and its Lighting
Posted By TonyW
Replies: 32
Views: 1,008
The correct lighting will make a huge difference to the viewing experience and for this special print IMHO needs some careful thought. Keeping out of direct daylight is great from an archival perspective. So now you will need to establish the correct light level and type of light to bring the print brightness up to that of your daylight viewing experience. You may want to experiment a little but FWIW;

For the size of the print my thoughts go immediately to some form of track lighting and preference now towards LED for colour rendering.

Hope these links may be of help.

8 Tips for Lighting Art: How to Light Artwork in Your Home | Architectural Digest
From layering to LEDS: how to light your artworks | Christie's
Forum: Film Processing, Scanning, and Darkroom 05-23-2018, 01:30 AM  
Folded 120 negative
Posted By TonyW
Replies: 15
Views: 997
Steve itís OK, no offence taken :)
Forum: Film Processing, Scanning, and Darkroom 05-17-2018, 11:01 AM  
Folded 120 negative
Posted By TonyW
Replies: 15
Views: 997
I disagree with your assesment of my post and your strange assertion that I am somehow spreading FUD.

The page I linked is correct (yours is not as relevant or informative!) and from the UK Health and Safety executive and while it may be seen to be applicable to large collections the principles outlined are sound.

The issue here is twofold the film type/base itself and dealing with the fold.

First the film, we really do not know if it is cellulose nitrate or safety film cellulose triacetate a plastic base. The former was used at least in professional film until around the early 1950's.

The HSE document linked to was not to cause FUD but to help the OP identify the film. Rather this than be complacent IMHO!

The only film that I have seen that I am sure of being cellulose nitrate has been old X -Ray film; brown and blistered surface. Which was carefully copied and the old film discarded.
It does not seem unreasonable to me to understand what you need to do or be aware of if the film is identified as cellulose nitrate.

There is no suggestion in either my post or the link that one should panic. Rather there is a very reasonable suggestion that if the film has viewable images to contact a conservator/film archive for advice on preservation.

I would also caution about the use at this time of any water bath (at any temperature) until you know what you are dealing with; it is quite disconcerting to see the image slide of the substrate unless you have an alternative substrate to slide it onto :D.

Of course non of this matters if the image is of no real value sentimental, historical or otherwise to the OP
Forum: Film Processing, Scanning, and Darkroom 05-10-2018, 10:41 AM  
Folded 120 negative
Posted By TonyW
Replies: 15
Views: 997
Take the film to a conservator. Safe to suspect the film Cellulose Nitrate, its manufacture continued in the 40's and even 50's




http://www.hse.gov.uk/pubns/indg469.pdf


Just be careful and play safe
Forum: Pentax Medium Format 04-27-2018, 09:11 AM  
Post your medium format photos!
Posted By TonyW
Replies: 12,533
Views: 2,045,331
This could easily be reticulation. Some films more likely to experience than others. I would consider safe films from the likes of Kodak and Ilford; safe in terms of less chance of reticulation.

The biggest cause of reticulation is big temperature changes occuring rapidly. So going from a 'normal' dev temp to cold fixer or even cold wash can cause a 'shock' to the emulsion with the result in reticulation.
Forum: Pentax Medium Format 02-23-2018, 08:13 AM  
645z color rendering I need help
Posted By TonyW
Replies: 31
Views: 2,790
I do not think the OP was talking about accurate colour rendition but rather finding too much red bias in his camera profiles. In this case tweaking profiles to taste and eliminating a red bias seemed to solve the issue as he reported getting better results at least closer to his requirements.

As (AFAIK) you cannot actually edit a profile using the X-Rite software. Under these conditions a shot of a colour card next to the model serves well as the basis for achieving a pleasing look that may actually appear more accurate to memory than a really accurate profile.

Your comment interseting andf I am curious so I will have a look at PEF and ACR export to DNG :)
Forum: Pentax Medium Format 02-22-2018, 07:15 AM  
645z color rendering I need help
Posted By TonyW
Replies: 31
Views: 2,790
This does not sound correct due to the fact that DNG is purely a specification of a non proprietary raw format which happens to have been written by Adobe. Several camera manufacturers have adopted the format including Pentax, Leica etc.

A DNG file is just a container for the raw data including space for the manufacturers own proprietary stuff if required (note only their software will interpret a correct rendering). So a Pentax or Leica DNG will actually be the raw data that a particular camera records i.e. unadulterated/unprocessed image data.

As with any raw conversion software you can expect different renderings and if the colour is 'off' then this will need to be corrected. To this end using either Adobe DNG profile editor or X-rite software you would expect some differences of rendering as you would in putting the files through any other editor.

Having used both I have not seen the behaviour you describe although I must say I prefer the Adobe DNG profile editor for the capability to tweak the profiles to taste.
Do you have any examples illustrating the difference in the workflow you describe?
Forum: Film Processing, Scanning, and Darkroom 02-19-2018, 10:30 AM  
What's wrong with my color scans?
Posted By TonyW
Replies: 13
Views: 987
My experience of Epson scan software is that it is more than capable of producing fine results with any medium and although not as many options as Silverfast or Vuescan.

IMO the results you are getting are due only to the pre and post scan settings being less than optimal and with a little work you should get quite acceptable results without swapping your scan software.

Happy to look further so if you want to post the same image as a straight scan i.e. as a negative will see what is needed to correct
Forum: Digital Processing, Software, and Printing 01-31-2018, 01:38 PM  
Pentax DNG and Lightroom performance
Posted By TonyW
Replies: 4
Views: 806
I believe what you are seeing is correct and you will normally see 'Not Validated' if you run the instruction on newly imported DNG's SOOC

Only DNG files created by Adobe software can be validated.

Those DNG's generated in camera cannot be validated because they do not contain the required checksum, but If you shoot and import PEF (or any other supported proprietary raw) and asked to convert to DNG then the checksum would be created and validation will work
Forum: Pentax K-3 01-27-2018, 03:22 AM  
Flash stuck
Posted By TonyW
Replies: 13
Views: 979
Perkele an excellent, informative and I am sure helpful post. Just what forums should be all about :cool::)
Forum: Troubleshooting and Beginner Help 01-22-2018, 04:04 PM  
Blurry DNG files in Lightroom
Posted By TonyW
Replies: 15
Views: 965
Something weird happening in Adobe products can often be cured by resetting preferences. You might want to consider using this option to see if it helps

Something Acting Weird? Try Resetting Lightroom CC's Preferences - Lightroom Killer Tips
Forum: Troubleshooting and Beginner Help 01-22-2018, 03:15 PM  
Blurry DNG files in Lightroom
Posted By TonyW
Replies: 15
Views: 965
Would have been helpful to post this in first post.
Photoshop ACR are the same raw engine so as you are seeing a difference some LR setting may be incorrect.

I donít think we are saying that all raw processing software is trying to give sharper images. Just the fact that they all apply defaults that differ and you should realise that all use their own proprietary algorithms to do a similar job.

A big clue here is that PS appears to be sharp and LR not. As they are the same raw engine then they should be exactly the same image processing parameters. So after you have processed an image in Photoshop Adobe Camera Raw and opened the image, that DNG should appear exactly the same when now opened in LR as all the edit instructions should be applied
Forum: Troubleshooting and Beginner Help 01-22-2018, 02:00 PM  
Blurry DNG files in Lightroom
Posted By TonyW
Replies: 15
Views: 965
I agree with Na Horuk raw software vendors can apply a default value to sharpening that may be more or less than another vendor. Adobe sharpening tends to be conservative vs others as is usually the case with their standard camera profile.

I cannot speak from recent personal experience of Acdsee or DCU but would be surprised if they are not just applying more as their default modes and by applying a little more Amount with LR/ACR that you would not be able to match
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 01-17-2018, 03:07 AM  
Hasselblad sensor shift creates 400Mp images
Posted By TonyW
Replies: 35
Views: 1,468
Asahi Pentax were the company to look to for innovation. This is not a full list but certainly impressive
Pentax cameras - Wikipedia
Forum: Troubleshooting and Beginner Help 01-16-2018, 07:24 AM  
Nikon D90 AF adapter
Posted By TonyW
Replies: 10
Views: 591
You have come across the limitations with this lens and body combination. IMHO it is highly unlikely that you will find any workaround to gain full CPU capability. I think the D90 brother the D300 offered better compatibility with non CPU lenses

You may find that a guesstimate of exposure coupled with the histogram is enough to be workable.

D90 lens compatibility:
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