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Forum: Pentax K-30 & K-50 07-10-2019, 01:50 PM  
Sticky: Manual solenoid replacement Pentax K30 / Discharge flash-condenser / Solenoid choice
Posted By Plentax
Replies: 204
Views: 58,662
Thank you very much Photogem for the detailed explanations.
I just repaired the green solenoid of my K-30 with success. In parallel I ordered a white solenoid on abay. It is quite expensive from Europe, but around 55 USD will be a-just-in-case insurance for me.

Why did I repair my green solenoid? Because I understood, that mainly the magnetic force of this green solenoid is too high compared with the white and better version. May be other parameters like tolerances are also important, but the green original solenoid in my camere did not make a bad impression. Just the high force. So I decided against the soldering solution described on a russian website, where the length and depth of the metall U-Shape has to be modified. I also think, that this is a bad idea. I decide to file the top of the "U" with an angle (see attached photo). Due to this the magnetic force will be lower, because the physical contact area of the metal "U" to the permanent magnet is reduced.

I do not expect any negative impact (compared to the soldering or drastic length modification), because only the physical contact (and magnetic force) between u-shaped metal and permanant magnet is reduced.

An my camera does work again!!!
Forum: Pentax K-30 & K-50 11-13-2013, 11:07 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
Yes, Picasa is dangerous. It even was modifying EXIF data in my write-protected JPG files. This ignorance of read-only files is a clear no-go for any software.
This happened with Picasa software about one year ago. I left Picasa immediately because of this, but I do not know if this behavior has improved since then.
LR, C1, ... and other good tools respect read-only DNG, JPG, PNG, ... files, but most of these tools are not able to use (read or create) XMP sidecar in this case.


A little bit unclear for. Which file format and which modifications (image, meta data) do you mean please?
Of course with PhotoShop you can overwrite any original file completely with the edited image. With non-destructive LightRoom you do not overwrite the original image, only the embedded DNG metadata and/or the embedded DNG preview image can be overwritten. The export from LightRoom is of course something else, because here you can deliberately overwrite existing files.



Thank you, that is a Class A understanding of my original issue and that is exactly the good solution with LightRoom. But I have to manage my DNGs also with other tools good tools (ExifTool, ExifTool-based SW, Imatch, ...) and I need to share ratings, labels, keywords, categories among them and Lightroom. With non-DNG raw files this works perfect through XMP sidecars, but with DNG apparently not at all. That was the reason for my original posting and the unrealistic "back-conversion" request.

Seems, that the only solution for a good workflow is to define one read-only master DNG and a slave writable DNG copy. But this doubles the required hard disk and backup space and increases the backup time dramatically. The additional files make the total number of files in LightRoom, DAM and file manager larger than necessary. Workarounds to circumvent some of the issues are are for sure possible, but they make the backup procedures, version management and DAM more complex.

Peter
Forum: Pentax K-30 & K-50 11-13-2013, 05:06 AM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
Thank you Jim,

yes, the "XX" was my fault when searching for Eneloop information. The number of battery types is too large and I am still confused, what exact type to use.
See the nice overview at http://en.wikipedia.org/wiki/Eneloop, which includes not only former Sanyo types, but also the most recent Panasonic types.
Which models in the good Wikipedia comparison table are now recommended for Pentax K-30? Has anyone experience with the new 2013 models?

Peter
Forum: Pentax K-30 & K-50 11-12-2013, 08:45 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
CaptureOne v6.4 definitively has big color problems with DNGs from K-30.
I was told that v7.x has no longer this limitation, but this version does not run with Windows 32bit.

See discussion and my image examples dated "08-02-12, 04:44 PM"
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/194485-dng-format-issues.html
I had a long discussion with PhaseOne about it and they reported, that every DNG content does need manufacturer specific interpretation.
Without information from manufacturer or deep research and investigation the rendering result will be limited.
Due to this some software rejects DNG from unsupported cameras. Other SW renders DNGs, but with weak result.

Peter
Forum: Pentax K-30 & K-50 11-11-2013, 08:56 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
This is another issue. YES the DNG data can be read by most RAW software, but NO the result may not be as expected. There are a couple of issue:
  1. Some free software included with digital cameras does read only specific DNG files from this camera manufacturer (e.g. SilkyPix).
    In order to read DNG from other cameras the user has to register and pay this software.

  2. Some software will not open DNG files from new camera models which are not yet supported.

  3. Some software cannot interpret the sensor data correctly, because the camera model is not yet supported. This can result in very different issues, e.g. brighness or color deviations. I experienced this for K-30 DNG files with CaptureOne v6.4. Only C1 v7.x seems to be able to read these DNG files correctly.

Important is, that you carefully check, that a software is really using the raw data in the DNG and not just displaying (or even processing) the embedded JPG preview. In order to see the difference I am replacing the full resolution preview in the DNG files from my K-30 allways with a medium preview. With this you can see immediately what a software is reallly doing. And you can reduce DNG file size a little bit.

So the fact is, that DNG files can contain proprietary camera data, which needs correct interpretation. This is a specific engineering effort, which requires time and communication with camera manufacturer. To my humble understanding DNG is just a standardized container (like ZIP file), which can contain proprietary raw content and non proprietary meta-text information.

Peter
Forum: Pentax K-30 & K-50 11-11-2013, 08:30 AM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
I think the basic issue with all batteries in the K-30 is the variance of voltage reduction vs remaining power. This variance is certainly depending very much on battery technology. Apparently the voltage detection levels in K-30 are quite sensitive. Since most Pentax users recommend the Sanyo Eneloop XX I have questions: Are the "Panasonic HHR-3XXe/4BC" with 2450 mAh the same type as the "Sanyo Eneloop XX" which can be found from 900, 1000, 1900, 2000, 2450, 2500 to 2550 mAh? Finally Panasonic/Sanyo is one company. Which Eneloops are the recommended ones? May be capacity is not the primary parameter for K-30, but the voltage decrease during usage?

And which chargers are best? In Europe I found the "Ansmann ENERGY XC3000" for 200 EUR or the "ALC 1010 Expert" for 100 EUR. I assume if µP-controlled single baycontrol , charge current control, voltage control and temperature control is supported, everything should be fine.
Forum: Pentax K-30 & K-50 11-08-2013, 04:21 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
Whaoo, that was a profound answer from amoringello. Good, helpfull, not only black&white. Thank you for sharing your view and experience.

I can confirm that backup of multiple small modified XMPs can be time consuming depending on backup tools and strategy.
But the sidecars do not contain very important information and can be regenerated quite easily from the DAM and Lightroom databases.
These databases are the core assets, which need consequent backup strategy. The XMP sidecars are just partial exports from them.
That is why I backup regularly all media files, but do not care so much about the XMP sidecars.
The sidecars can very helpful in the case of migration between different tools,
because a direct meta data transfer between databases is normally not possible.

The key issue behind is, that both: 1. the XMP sidecar concept or 2. the XMP embedded concept
cannot be realized completely for all file types/extensions from most DAM and image editor tools.
Case 1 is not supported from most tools and case 2 is only possible for a few file types.
Everybody has to find his individual workflow and tools with this metadata discrepancy.

Peter
Forum: Pentax K-30 & K-50 11-08-2013, 03:03 AM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
Thanks for sharing this experience.
Yes, I think my AL and Ni-MH batteries are really all garbage.
Including a cheap non-Pentax D-LI109 from Ebay, which is awfully bad and waste of money.

I will change to AA Lithium and Ni-MH Eneloop and continue to use the original Pentax D-LI109.
And I will check how the standard non-rechargable AL AA batteries behave with the camera setting on Ni-MH.

Peter
Forum: Pentax K-30 & K-50 11-08-2013, 02:55 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
That is not fully correct. For JPEG, TIFF, PNG, PSD and DNG files, Lightroom can/will save metadata directly in the files.
Of course LR does not modify the original image content, but the embedded XMP data is modified.
For all other supported files metadata will be written to sidecar XMP files next to the original photo.
With DNG files there is also the option to update modified preview and metadata in the file.

If a user wants to keep JPGEG, TIFF, ... untouched (not modified) there is no real chance with LR.
Write protection does not help, because LR reports an error in this case.
The requriement to use XMP sidecars can have multiple reasons:
  1. Backup process and speed

  2. Protecting original files

  3. Principle

  4. Avoid placement of proprietary data in original file

Regarding point 4, all LR edit data is proprietary and cannot be used by other software including some other Adobe software.
Why should I "pollute" my valuable original files with proprietary data and make the backup process too complicated and with overhead.

I like to use XMP sidecars for ALL my original media files. With DNG and LR this looks impossible.
Other tools like GeoSetter, JPhotoTagger, Imatch, Idimager, PhotoSupreme, ... can respect this requirement.

In another forum I read about the proposal to keep always two DNG files: One original DNG and a working DNG copy for editing.
This workaround is of course feasible, but is a big waste of storage and still complicating the regular backup process.

Peter
Forum: Pentax K-30 & K-50 11-07-2013, 09:40 AM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
Thank you Jim for this good explanation. I couldn't describe it better and I have studied electronic engineering plus PhD.
Apparently my good Panasonic AL batteries and rechargabel Ni-MH have a too strong voltage reduction (even when still with reasonable power). Especially when switching on the LDC display the temporary "current" and "depletion" effect is very strong. I wonder what will happen now in the long term , when I switch the type selection always to Ni-MH when using AL batteries. Thank you for the hint with 2nd generation Ni-MH. I certainly will test and consider this. Luckily I have already a professional and quite expensive 120 USD battery charger for various battery types.

Replacing the 4 AA cells with Li-ion instead of AL or Ni-MH is certainly no real option, because the high voltage 3.7 Volt of one Li-ion cells would require too much modification of the battery holder. However the drastical increased capacity of advanced 4 x Li-ion AA cells versus the original D-LI109 capacity sounds promising. May be an idea for a modified battery holder with two parallel branches of two serial AA Li-ion batteries?

My external flash does use also 4 x AA cells. With this it is very attractive to use the same batteries for K-30 and flash.

Peter
Forum: Pentax K-30 & K-50 11-07-2013, 03:16 AM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
Of course DNG files are RAW files. My wording was perhaps not good enough, but you hopefully understand my wish to protect DNG files from being edited.
I am a non native english speaker/writer.

Shall I name a proprietary raw file from camera PRAW. But what is then a DNG file with embedded PRAW compared to a DNG file without embedded PRAW?
And finally the embedded image information in DNG can be still camera manufacturer proprietary and without special knowledge a tool cannot display and process the raw content correctly. This is still the case with version 6.x of CaptureOne. And in C1 version 7.x the K-30 is not mentioned as supported (but there are romours that this should be the case).

Let's try it again. To my knowledge there are a couple of different types of RAW files:
  1. original proprietary RAW files directly from camera with file extensions *.CR2 *.RAW *.IIQ *.PEF ...

  2. original DNG file from camera

  3. converted DNG files from 1. without the original raw data

  4. converted DNG files from 1. including the original raw data

  5. converted DNG files 2.-4. with modified preview (no, medium, large)

  6. proprietary RAW file containers (e.g. ZIP files) with file extensions like *.EIP

  7. modified DNG files from 1.-5. which include proprietary modifications stored by RAW editor or text metadata modified by DAM software

I like to protect completely my original files from camera (both 1. and 2.) and like to avoid case 7. completely!
This is easily possible for files 1. but apparently not for files 2.
Write protected DNG files are not supported from a lot of tools including Lightroom, when you prefer XMP sidecars. By the way very similar to JPG files.

Peter
Forum: Pentax K-30 & K-50 11-06-2013, 08:14 PM  
DNG back to RAW conversion?
Posted By Plentax
Replies: 18
Views: 6,579
Is there any way to convert the Pentax DNG format from K-30 back to a RAW format (PEF, ...)? Note that only DNG and/or JPG and no PEF can be be created in the K-30!
The reason for this strange request is, that I dislike modifications of my image files from software like Lightroom or other tools and I prefer XMP sidecar files.
This has also big benefits for backup speed.

Setting read-only attributes for DNG files is no solution, because depending on program settings, Lightroom and other DAM tools still want to update DNG with metadata or updated previews. If DNG files are read-only error messages or blocked tools (e.g. through infinitive ExifTool loops) can result.

I tried to rename DNG file extension to something else (e.g. *.rah or *.pex). It is interesting, Lightroom v5.2 still identifies DNG and is able to edit the files. But sadly Lightroom will still read and embed the XMP date in such files. Other DAM tools will not read such files at all and some others tools (e.g. IMatch) will read and write sidecars and even can display the preview of such files correctly.

Peter
Forum: Pentax K-30 & K-50 11-06-2013, 07:50 PM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
Thank you Jim,

yes I checked of course the correct battery type setting in the menu. This settings has a big influence on the depletion switch-off situation. You even can "lock" your camera, when you set the "wrong" value, because apparently the voltage level which decides about depletion (4 x 1.3 Volt of AL) can be higher than the typical voltage of another battery type (e.g. 4 x 1.2 Volt of Ni-MH). Unlocking is only possible with inserting correct types and then selecting the correct value. Can you or someone confirm that it is only the voltage which is used as criteria for the depletion status of a battery in the K-30? May be you are on the safe side with the 4 battery case, when you select always Ni-MH mode?

I just tried to set (wrong) Ni-MH type for non rechargable AL batteries (which are not at all empty). With this setting the K-30 does show 50 % battery level. I assume this level will be kept for a very long until the AL battery is really depleted. When I switch battery type to the (correct) AL type, the camera is immediatly switching-off after depletion message. With this my current workaround is to used standard AL batteries, but to set the Ni-MH type different in the menu. Any better hints?

I am considering to try 4 special rechargable Alkaline Manganes (RAM) batteries, which have 4 x 1.5 Volt nominal voltage instead of only 4 x 1.2 Volt. May be such batteries do no show the problems in the K-30?
Such RAM batteries need special charging and are not recommended for high current devices (like digital cameras?). Is this also true when you do not use the internal flash at all?

Regards, Peter


P.S.: I wonder how the automatic battery type detection in the K-30 does work. May be it is better to avoid this setting completely?

P.P.S.: I just read, that the RAM rechargable batteries are very sensible when beeing discharged too much. With 25 % discharge they can be charged about about 100 times, but with 50 % discharge this value can be reduced to 10 times. It looks like RAM batteries are really not suitable for digital cameras, because discharge level cannot be controlled well.

P.P.P.S.: And what about using Li-ion AA batteries with each 3.7 Volt and each from 750 up to 1200 mAh? With modification of electrical wiring in the battery holder you could use either 2 x AA or parallel 2 x 2 x AA and a total of 7.4 Volt. The total mAh capacity would be much bigger than the original Pentax Li-Ion battery. But of course all this on your own risk ... and if the camera burns you do not need high ISO or flash light any more :-)
Forum: Pentax K-30 & K-50 11-06-2013, 09:58 AM  
Battery depleted
Posted By Plentax
Replies: 16
Views: 10,269
I like to continue this post, because I experience huge battery depleted problems with my K-30.
I use the original Li-ion (LIB) rechargable battery and also 4 x AA standard Alkaline (AL) non-rechargable or 4 x Ni-MH rechargable batteries.

Normally I use flash very seldom and I keep the rear display swithed off most of the time.
But as soon as I used flash or display too much the battery depletion message and switch-off occurs very soon.
After a short recovery period for the batteries (some minutes) everything is fine again.

This behavior depends also on the battery type selection in the menu settings (Auto, Li, Ni-MH or AL).
If I switch to the correct setting, it can happen that the camera does not like to start. After inserting a full battery I can change the setting and replace and use another battery again.
I have the strong suspicion, that the menu setting is just defining a voltage level for measurement. With this the lowest voltage seems to be the NI-MH and the highest level seems to be Li.
But nevertheless even a small reduction in voltage results in depletion warning and camera switch-off.

The Li-Ion battery standard voltage is about 7.4 Volts.
The AA Ni-MH standard voltage is about 4 x 1.2 Volt.
The AA AL standard voltage is between 4 x 1.3 and 4 x 1.5 Volt

It seems, that as soon as the voltage of 4 x Ni-MH and AL batteries is starting to lower a little bit, the camera does not like to work.
I tested the partial depleted batteries with a professional battery tester and indeed they still have a quite high capacity.
As soon as the total voltage is below 5.5 Volt, which is 4 x 1.375 Volt, the K-30 does show problems.

I have the strong impression, that the K-30 battery voltage sensor is much too sensitive for 4 AA batteries.
With rechargable AA batteries this sensitivity is even higher.
May be instead of 4 AA batteries Pentax should have better designed the camera with 5 batteries in order to get a sufficient voltage?
Forum: Pentax K-5 & K-5 II 04-29-2013, 09:10 AM  
EV compensation
Posted By Plentax
Replies: 17
Views: 2,841
The histogram is only a helpful characteristic of brightness distribution inside an image. You can display histogram also for only R,G or B color to identify the statistical distribution of colors. If there is nothing on the left (dark) or right (bright) side of histogram you have no dark or bright colors in your image. If you have too much on the left or right, you have to much darkness or brightness in your image. Depending on the real content of your image, this statistical distribution is wanted or unwanted and you can correct this in the photo/raw editor or better already during photo shooting. With the histogram before/after shape you can also see clearly what a photo editors is doing on your image.

Reliable calibration of a monitor is only possible with specific measurement equipment and software. This is not very expensive, but worth the price, because you can trust your image manipulations much more and only with a calibrated monitor. I have done all my monitor, TV set and projector calibrations with Spyder 3. You can try to do a very rough calibration with popular test pictures alone, but this cannot compete at all with a good calibration based on measurement.
Forum: Pentax K-5 & K-5 II 04-29-2013, 04:23 AM  
EV compensation
Posted By Plentax
Replies: 17
Views: 2,841
Thanks KerrowDown for the remark about JPGs.

Yes, this is a common misunderstanding. The white balance, noise reduction, display bright/dark area warning and a lot of other features are only valid for JPGs and not for RAW/DNG. What you see on the PC screen with DNG depends of course heavily on the RAW-processor and monitor calibration. I used both CaptureOne (C1) and LightRoom (LR) for my DNGs from K-30, but had to give up with C1, because the colors are displayed terribly wrong . PhaseOne is not able since summer 2012 to provide any support in C1 for DNGs from K-30.

Regarding histogram shape, I am not yet sure (not enough experience) about the difference of K-30 and LR histogram. LR does show of course the DNG histogram, but what is shown on the K-30 rear display? I assume the JPG histogram, isn't it? And this histogram with its dark/bright warnings is certainly only a rough estimation for real DNG histogram.

Regards, Peter
Forum: Pentax K-5 & K-5 II 04-26-2013, 06:49 AM  
EV compensation
Posted By Plentax
Replies: 17
Views: 2,841
Again I learned recently in a photo seminar from a real expert the good rule ETTR (expose to the right). This mainly to be able to benefit as much as possible from the dynamic range of sensor and the linear/nonlinear relationship. Of course this does only make sense with RAW/DNG images and not with JPG.

Is it possible to add allways a certain EV Compensation to the K-30? The compensation button (1) can be used for this, but each time the green button (2) is used, the EV value is reset. Sometimes I need the green button (2) for other purpose and I still like to have the EV compensation enabled. Seems like there is not solution, but in case I miss somethink, I say thank you for any hints.

Regards from Peter
Forum: Pentax K-30 & K-50 02-18-2013, 04:29 AM  
Image size vs quality
Posted By Plentax
Replies: 7
Views: 2,947
I do not understand. The questions of OP (original posting) are place in K-30 forum and about JPG. So RAW-DNG conversion is not required for K-30.

If you like to save memory, I would recommend to use just DNG from camera without additional JPG file. I am even converting the original DNGs and replace the embedded full size JPG preview with a medium size JPG preview. For this I use free! (no question mark) AdobeDNGConverter. So the original DNG from K-30 (4928x3264 pix) are reduced in size from e.g. 12.641 MByte to 10.544 MByte. The medium size preview JPG is really small. If I generate a DNG without preview, the size in this example would be 10.512 MByte. So the embedded JPG preview is only 32 kByte. Note that the updated preview no longer includes K-30 lens correction.

Summary for one example image 4928x3264 pix taken with K-30 and converted with AdobeDNGConverte v7.2:
  • Original JPG: 5.941 MByte

  • Original DNG: 12.641 MByte

  • Extracted JPG: 1.628 MByte (extracted with ExifTool from original DNG)

  • Converted DNG: 11.320 MByte (updated full size preview, does not make really sense)

  • Converted DNG: 10.544 MByte (medium size preview, 1024x678 pix)

  • Converted DNG: 10.512 MByte (no preview)

The only special thing I do is, that I export the embedded full resolution JPG preview to a separate file with ExifTool before my DNG preview conversion. This, because I like to have the lens conversion of K-30 just for comparison, which is only in the original JPG preview or original separate JPG file. But I do not need the high quality and size (e.g. 6 MByte) of separate JPG and can live with the smaller export size (e.g. 1 MByte) of embedded full resolution JPG preview. If you really need high JPG quality there is always the DNG available for all kind of raw processing. I can recommend strongly the medium size preview DNG. Not only the file size is smaller, but also every image software tool, which is not able to process the raw content will display or process only the medium resolution preview. So you can detect very easy, if something is not working properly in such software. With IrfanView for example there is another benefit: The display of preview is much faster, but you still can define in the program settings if you like the original raw or half-size raw image be used for display (which is of course much slower).

Yes, any reduction of JPG size and compression is immediately visible as degradation. Sometime not so obvious, but often you can detect it very easily when looking for small details in zoomed mode or for slightly changing color areas in the image (e.g. blue sky).

Regards, Peter
Forum: Pentax K-30 & K-50 02-14-2013, 03:58 PM  
DNG format issues
Posted By Plentax
Replies: 65
Views: 18,556
Short update: From CaptureOne no news at all. Even new v7 for only Win-64-bit does not support DNGs from K-30. No support does mean: still really terrible wrong colors. I am back to Lightroom v4.2 now since several months and everyhting is fine for K-30 DNG files including lens support.

I still do not understand why K-30 is listed as supported with AdobeDNGConverter v7.3.0.71. I am converting my DNGs just to get rid of the large embedded JPG preview. I cannot identify any difference of DNG before and after conversion. I assume that the DNG raw-data is really untouched during conversion. The DNGConverter can do compression or fast load. May be here the camera support is relevant? But I do not use such special features and especially fast load seems to be incompatible with some popular image browsers.

Regards from Peter
Forum: Pentax K-30 & K-50 02-11-2013, 05:40 AM  
User modes
Posted By Plentax
Replies: 7
Views: 1,486
I am using the user mode now for a special setting with an old external Nikon flash.
May be even more than only 2 user mode would be required after all for the K-30?

Regards, Peter
Forum: Pentax K-30 & K-50 02-06-2013, 03:38 PM  
K-30 with Nikon SB-20 flash
Posted By Plentax
Replies: 3
Views: 2,578
May be a little bit unusual combination, but I still have a Nikon SB-20 flash and consider to use it instead of an expensive new flash.
Guide Number is about 100 ft(30 m). To my knowledge the AF assist red LED cannot be used and the only supported mode with non-Nikon is the manual mode.
For me the flash power looks impressive and the adjustable diffusor from 28 over 35 to 85 mm (= 18...55 mm APS-C) fits more or less to my Pentax 18-135 WR lens.

Does anybody else use this flash and likes to share experience and best practises K-30 settings?
My first experience is good as long as you know exactly how to adjust the correct flash power (full, 1/2, 1/4, 1/8 and 1/16).
The rear display on the flash can help to find correct settings, but I still have to get a feeling for best camera/flash settings.

Regards, Peter
Forum: Pentax K-30 & K-50 10-31-2012, 04:16 PM  
DNG embedded previews
Posted By Plentax
Replies: 1
Views: 1,655
A detailed investigation of previews in original and converted DNG files from K-30 gives interesting results.
Here are details for an example image, which was also converted with AdobeDNGConverter v7.2:
  • Original DNG: 16,218 kByte, 4928 x 3264 (4936 x 3272)

  • Original JPG: 7,063 kByte, 4928 x 3264

  • Converted DNG without preview: 14,345 kByte

  • Converted DNG medium preview: 15,261 kByte

  • Converted DNG full preview: 16,771 kByte

I extracted the previews with EXIF Tool v9.03 and the following parameters:
  1. exiftool -b -copy1:PreviewImage -w %%f_cp1.jpg -ext DNG -r .

  2. exiftool -b -PreviewImage -w %%f_pre.jpg -ext DNG -r .

  3. exiftool -b -JpgFromRaw -w %%f_raw.jpg -ext DNG -r .

The command "exiftool -b -ThumbNailImage" did not result in any JPG export. I also crosschecked with the special command "exiftool -b -BigImage". The results for exported JPG previews from above DNGs are as follows (The red numbers are results with above EXIF-Tool parameters):
  • Original DNG: 1. 1436 kByte 4928 x 3264, 2. 1476 kByte 4928 x 3264

  • Converted DNG without preview: 2. 40 kByte 640 x 480

  • Converted DNG medium preview: 1. 131 kByte 1024 x 678, 2. 170 kByte 1024 x 678

  • Converted DNG full preview: 1. 134 kByte 1024 x 678, 2. 174 kByte 1024 x 678, 3. 2292 kByte 4928 x 3264

The compression quality of original JPG and previews is quite different (98% and 34%, 49%, 82%). It seems also, that some JPGs use color subsampling and others not. Interesting is, that the converted "DNG without preview" includes data, which can be exported with EXIF-Tool as 640x480 JPG, but this data apparently is not used for DNG display from image viewers like IrfanView. Finally the converted DNG with full preview is larger than the original DNG, because the full resolution preview quality increased from 49% to 82% and its file size from 1436 to 2292 kByte. I know also, that there might be other preview data (TIF?) in the DNG files, which is used from specific software. But I do not know how to extract this data and if this is really relevant for usual image software.

Currently I am shooting always DNG+JPG, but I am not sure if the JPGs are really required. They are quite large, but on the other side the previews in the original DNG are smaller and have less quality. May be it is better to create new high quality JPGs after RAW processing and the original JPGs are useless and justing waisting SD card and disk space?

I also convert all DNGs to DNG with medium preview, because I do not like full resolution previews in DNG files. First I like to control, if other software is using previews or is really rendering the DNG. This is not possible with full resolution size previews. Second I like to keep the DNGs small, write protected and with XMP sidecars. This speeds up backup! So I have no intention to update previews or metadata in the DNGs.

Any comments about this confusing preview situation from your side?

Regards from Peter
Forum: Pentax K-30 & K-50 10-06-2012, 10:21 AM  
DNG format issues
Posted By Plentax
Replies: 65
Views: 18,556
Since 2012-10-02 there is a new version AdobeDNGConverter with v7.2.0.46 available at www.adobe.com/support/downloads/detail.jsp?ftpID=5486. It lists explicitely the Pentax K-30 as new supported camera. Up to now I converted my K-30 DNG files with v7.1 without problems. My main motivation to do so was the reduction of preview size from full resolution to medium resolution. That is quite important for me, because a lower resolution preview is a very good mean to identify software which does not render the raw content but only the preview of a DNG file.

But what does it mean now, that v7.2 of AdobeDNGConverter supports K-30? The K-30 does anyhow produce ONLY DNG files. Is there an additional need to convert again? Why? Will the problems with CaptureOne and other software dissappear? What happens if you convert with v7.2 again the DNGs which have been already converted with v7.1. Will it be necessary to reconvert again and again all DNGs? A lot of questions, which are nowhere at Adobe website answered. I will post any new findings after my own investigations, which will take some time. But it is good to have this forum for sharing.
Forum: Pentax K-30 & K-50 09-26-2012, 09:34 AM  
DNG format issues
Posted By Plentax
Replies: 65
Views: 18,556
Thank you for checking. I assume you mean the last jpg of colorchecker chart screen shot in one of my previous postings. Yes this looks a litte bit bright, but the colors look more correct. I like to try again a better ICC correction profile for CaptureOne, but the bug of C1 with local adjustments makes me strongly hesitate to spend this effort.
Forum: Pentax K-30 & K-50 09-26-2012, 06:05 AM  
DNG format issues
Posted By Plentax
Replies: 65
Views: 18,556
I found out that C1 does not show local adjustments, when such ICM profile is applied. The adjustments are performed, but are no longer visible. Looks like a bug either with C1 or with the ICM profile? Ticket at C1 was submitted and solution is still pending.

The support of DNGs from K-30 seems to have no priority at all for Phaseone. So I am looking for another way to convert DNG2TIFF and process the TIFFs in C1. Does anybody know which which tool and file format (PNG-24, TIFF-32, ...?) is best for this conversion process. K-20 DNGs are 12 bit and I don't want to waste bits if not needed.

Another issue is the very very different support of original DNG (with embedded full preview) and converted DNGs in various software tools. I converted with AdobeDNGConverter to 3 DNG variants: with no, with medium and with full resolution preview. Various DAM tools and image processors create the screen or any export file format either from preview or from original raw content. The results are heavily depending from software settings (WIC, no WIC, FPVC, DCRAW, ...) and also from windows operation system.

Seems like we have to wait very long for full and absolutely defined support of DNG in image software. A new camera like K-30 creates additional risks for users on top of the already limitations with DNG. (e.g.: Try to open K-30 DNGs in AfterShotPro -> nothing happens at all).
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