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Forum: Pentax Medium Format 03-05-2014, 09:25 AM  
Pentax 645N apperture mismatch and metering inaccuracy
Posted By sniper29a
Replies: 12
Views: 3,547
I have read Ken's thoughts about the camera. But missed info about lenses. I see it is quite common problem. I have got SMC-A 45-85, SMC-A 80-160, SMC-A 120 macro. All mentioned lenses show what was described earlier. I do not see focal lens imprinted on negative. I always use lens ring as I consider it as accurate.

---------- Post added 05-03-14 at 09:29 ----------



Thank you sir, that's what I wanted to hear. I trusted always ring since it is mechanical with lever by flange/mount of lens.

I will shoot a test roll with common scenes I shoot. If I see consistent results I will compensate according my notes. Galen Rowell has also written that every camera measures different. For instance his NIkon F4 with Kodachrome ASA64 gave best results at ASA80 EV+1/3

If I don't get consistent reading after test, I will seek an expert for reapair
Forum: Pentax Medium Format 03-04-2014, 01:18 AM  
Pentax 645N apperture mismatch and metering inaccuracy
Posted By sniper29a
Replies: 12
Views: 3,547
Image from DSLR and transparency were compared and my Canon 5D.2 is always consistently spot on with exposure metering and AWB. Also my good old "75MPx" Canon 3D was always spot on so I wonder whether is that common Pentax feature or just my camera is broken. I have seen this phenomen by my ex-DSLR Pentax K-7

Looks like, I will have to send camera somewhere for inspection once I find professional service in Europe.

Velvia is known for its sensitivity of correct exposure.
Thanks for suggestions
Forum: Pentax Medium Format 03-03-2014, 11:24 AM  
Pentax 645N apperture mismatch and metering inaccuracy
Posted By sniper29a
Replies: 12
Views: 3,547
I usually shoot velvia 50 or provia 100f.

The scene I noticed inaccurate metering is this waterfall Photo of the month – January | David "HAJES" Hajek Fine Art Photography (BETA) (this picture is from DSLR)

I bracketed this scene. EV0 underexposed. EV+1.0 spot on at least what I have seen on light table. There is overblown highlights which may fool metering of camera.

An other scene was landscape reflection in water with Provia 100F and EV0 was spot on.

Otherwise, as someone said...I already take notes and will adjust accordingly.

Camera came from respectable German Dealer. But I guess they just check if camera works mechanically and that's it.

thanks for suggestion guys

---------- Post added 03-03-14 at 11:27 ----------



I am not sure whether you have understood my question or just my english is weak.

I have asked for two unrelated issues.

Aperture ring and viewfinder F number doesn't match.

And metering inconsistency. Unsure, why you refer aperture is cause of metering inconsistency.
Forum: Pentax Medium Format 03-02-2014, 12:24 AM  
Pentax 645N apperture mismatch and metering inaccuracy
Posted By sniper29a
Replies: 12
Views: 3,547
Thanks Yuri, all checked and manual double read in case notorious Chair<>Keyboard syndrome :-D

Looks like Pentax have long history of metering inconsistency and in case of DSLR also AWB. My former Pentax K-7 was most time off exposure metering and AWB (Auto White Balance) always off
Forum: Pentax Medium Format 02-28-2014, 11:39 AM  
Pentax 645N battery life
Posted By sniper29a
Replies: 7
Views: 4,113
thanks chief. I only use Energizer Lithium Ultimate in all toys I carry in mountains. It is simply the best and cheapest batteries I have ever used.
Forum: Pentax Medium Format 02-28-2014, 11:36 AM  
Pentax 645N apperture mismatch and metering inaccuracy
Posted By sniper29a
Replies: 12
Views: 3,547
Hi,

I have just bought used Pentax 645N with 45-85 and 80-160 and 120 macro lenses.

First, I have noticed that no matter what lens aperture number on ring doesn't match what is on display inside viewfinder. My question is what should I trust? Ring on lens or electronics inside the camera?

Second, I have noticed some metering inaccuracy. In shadows, it seems it is off 1EV. Since I am testing/learning how this camera behave. I always bracket shots and all +1.0EV looks normal too me. 0EV is underexposed. BUT, it was scene where was too many similar colours so I guess metering was fooled despite Ken Rockwell says it is spot on only film emulsion compensation may be needed.I have also taken a landscape where is diverse brightness and colours and there is is metering spot on. So I guess it is common problem with automatic metering if one color prevails in scene for instance.

Could you provide further information who has this camera, please?
Forum: Pentax Medium Format 02-05-2014, 12:49 PM  
Pentax 645N battery life
Posted By sniper29a
Replies: 7
Views: 4,113
thanks. that what manual says. But there was no Energizer Lithium Ultimate back then :-D So I wonder how many batteries I have to buy.
Forum: Pentax SLR Lens Discussion 02-05-2014, 12:48 PM  
DxO are frauds.
Posted By sniper29a
Replies: 51
Views: 5,854
What half do you mean? Spending hours in front of computer instead of shooting?
Forum: Pentax SLR Lens Discussion 02-05-2014, 12:46 PM  
DxO are frauds.
Posted By sniper29a
Replies: 51
Views: 5,854
Question is what Aperture does? There was long outcry about DxO performance. 1min per image is too long for some ppl who doesn't understand that DxO will make "perfect" image from shit photo system combination.

If you like Aperture. Good for you. I have tried few years ago, but not impressed by results. Same problem like Adobe Product. Closest call is Capture One SW.

Question is how big picture do you print? If you print A4 - A3 there is no need for any SW. It doesn't matter. Anything bigger is where DxO kicks in.

Don't worry about theory and some synthetic wall tests. Just try it without prejudice and you might be surprised.
Forum: Pentax Medium Format 02-04-2014, 10:35 PM  
Pentax 645N battery life
Posted By sniper29a
Replies: 7
Views: 4,113
Can anyone confirm official battery life for Pentax 645N? How many rolls of film do you make per battery pack. Most interested for me is very cold weather with Lithium battery. Thanks for answers.
Forum: Pentax SLR Lens Discussion 02-04-2014, 11:33 AM  
DxO are frauds.
Posted By sniper29a
Replies: 51
Views: 5,854
As I tried to explain. DxO Mark is for wall photographers. Carl Benz in photography world. In other words, ppl who bother too much about theory and shoot 1 picture of wall per year. For real life pro, this data doesn't mean anything. It is just foundation for DxO algorithms. As I have said, it is made in controlled test condition.

One of reasons why I have left Pentax system 4 years ago is lack of lenses and pro features. I used to have Pentax K-7. Lenses are biggest problem with Pentax. Pentax DSLR focuses on hobby market thus there is no expectation for real life photography.

As someone had said DxO doesn't consider Pentax photo system as pro tool so they don't invest too much money in testing Pentax combinations. On other hand Canon and Nikon is well covered in almost every wildest possible camera lens combination.

I know that I have set camera for RAW output with consistent settings. During photo session I bother only about correct exposure and pre-visualisation. I don't have time to tinker with camera setting during taking pictures due quick change of light conditions. When I got back to base camp, I upload and backup pictures. Start up DxO and it spits every 30s 6 images of corrected pictures. Done. Quicker than getting it done on the place and play with useless and chaotic settings of every camera even with pro cameras.

Botom line, every picture needs 30s of post-processing. Job done, I can move on at next project. Unless, it is fine art and it needs further processing in Adobe PS. Once again....DxO spits every 30s corrected TIFF, ready for local adjustments.

With Aperture or Lightroom. It takes ages, too many useless features that nobody uses except e-experts and wall-photographers. Whole work flow is pain in a*s. I rather shoot than bother about post-processing like most ppl do. Ever lasting "problem" since dawn of photography. Lenses are pish, cameras are rubbish. Everything is rubbish for amateurs since it is easier to blame everyone else rather than incompetence in focusing right, getting composition right. But god bless these ppl since I can buy cheap photo gear.
Forum: Pentax SLR Lens Discussion 02-03-2014, 11:03 AM  
DxO are frauds.
Posted By sniper29a
Replies: 51
Views: 5,854
I use DxO Optics Pro Elite for over 4 years. Best SW I ever purchased and worth well money invested. Lightroom and other SW are far away from quality DxO OP produces. I would say that you misunderstood what DxO does. These values are for e-experts and tech onanist. They are useless for real life photography. Whole reason DxO does this controlled test is to determine lenses and camera flaws. These theoretical values are then used in DxO Optics Pro to correct images.

Bottom line. Output of DxO OP based on controlled tests of cameras + lenses combinations is what matters most. It is "magic" ;-) Sure, I use also Adobe PS CR. But it never gives me what I want unless I fiddle with all fancy sliders. I rather take pictures and let DxO do the job. Since I have got this state of art SW, I don't bother about lens quality since all is corrected by DxO. Simply clever.

Don't bother about theoretical results and shoot ppl.
Forum: Digital Processing, Software, and Printing 11-04-2010, 01:24 PM  
Your RAW workflow
Posted By sniper29a
Replies: 33
Views: 13,505
thx for info. if I use just optical correction functions of DxO I have no problems too. But once I start to do more adjustments, bang crash.
Forum: Digital Processing, Software, and Printing 10-30-2010, 06:52 AM  
Your RAW workflow
Posted By sniper29a
Replies: 33
Views: 13,505
eddie1960: what version of DxO do you have? I tried latest version (6.2) due the one of the best optical correction function. Otherwise, DxO Optic Pro is pretty unstable program to work with. Do you have stability problems as well?
Forum: Digital Processing, Software, and Printing 10-29-2010, 09:11 AM  
Your RAW workflow
Posted By sniper29a
Replies: 33
Views: 13,505
Problem with GIMP is very poor RAW workflow. There was thread about it as well. 64b version of GIMP is sporadic under windows and windux is no option for me due special SWs I use.

It depends on the purpose of SW. Photoshop Elemenets/GNU SW is sufficient for majority users. Most ppl take picture and put it on web. No need of any special SW packages for hunderts. Anything will do for WEB output, even for printing of family photos. Unless, someone has got expensive high quality printer and uses pro papers as well.
Forum: Digital Processing, Software, and Printing 10-27-2010, 12:34 PM  
System Requirements for CS5/LR to "do it right"?
Posted By sniper29a
Replies: 25
Views: 9,663
if you decide to build your own comp. i suggest you to spend most money on high quality Motherboard and memory. Unless you love unstable system. Gygabyte MoBo is good choice and Transcend/Crucial memory as well.

Unless, you like framerate masturbation. I would suggest you to go for AMD system. Optimized system based on most components from one manufacturer. low power consumption compared to Intel. in case you use linux. main argument of Intel crowd is poor performance. No wonder if Intel/MS accidentally disadvantage compiler towards AMD. Unfortunatelly, all Windows applications are well optimized for Intel platform and AMD looks bad.

AMD CPU+AMD chipset+AMD/ATI graphic card = most stable system with perhaps 15% less performance compared to Intel, with 20% better power efficiency and used to be at lower price too.
Forum: Digital Processing, Software, and Printing 10-27-2010, 12:19 PM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
If provided picture is example of realistic look provided by your friend. It doesn't look too realistic to me.

Color shift toward red. Which may be intention during the sunrise. From second look, grass and bushes in front don't look realistic at all. yellow color shift. this picture doesn't reflect reality at all.

I wonder what this picture tries to says. cold mood would reflect this place much better. I wonder why this picture was even made by HDR trick? I think dynamic range would fit anyway.
Forum: Digital Processing, Software, and Printing 10-26-2010, 10:45 AM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
HDR programs may be good and easy way for non moving images with not too high contrasts around edges (sky vs. wood branches ffor example).

i have used photomatix for these cases and results were decent for web. small images will hide all problems of HDR after interpolation.

i doubt HDR programs are any use for fine art where quality is crucial.
Forum: Digital Processing, Software, and Printing 10-26-2010, 10:41 AM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
whenever you get too many overblown images in blending. i doubt any SW will be able to get decent result. I assume all these programs estimate some average values. in other words, if you expose outlook from window right. you get nice dark edge of window. once you overexpose details of windows as I have seen in one of your pics. there is problem for SW. overblown edge is 5pixels (example) shifted towards the window details (inside of room). that is why you get halos, emphasized by chroma abberation and result is horrible. basically, SW is painting something what is not there adn just averaging pixels.

I see only one possible course of action for this test.

1. HDR SW - 2 pictures with properly exposed outlook from windows and not much overblown details of wall around window. Then result may look somehow decent. most likely not much details in wall around

2. any photo editing SW - 3 pictures. 2 pics same like in previous example + 1 more pic for wall which will overblowwindow details. this picture would be masked with nice blured transition to remaining 2 pictures. results will be most accurate with highest quality possible
Forum: Digital Processing, Software, and Printing 10-26-2010, 10:29 AM  
System Requirements for CS5/LR to "do it right"?
Posted By sniper29a
Replies: 25
Views: 9,663
how do you use graphic card as swap?
Forum: Digital Processing, Software, and Printing 10-26-2010, 10:27 AM  
System Requirements for CS5/LR to "do it right"?
Posted By sniper29a
Replies: 25
Views: 9,663
warranty - exactly same like you buy anything else. support - you will be responsible for assembly, not other company. in case something doesn't work and you know what you do. you don't need any support. despite they try to look like professionals, support is not much different from ppl like you.they rarely know what to do.
Forum: Digital Processing, Software, and Printing 10-25-2010, 05:47 AM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
Don't forget overblown edges will result in edge burn and color leaks. Result is clearly seen on your final picture, even on small picture.
Forum: Digital Processing, Software, and Printing 10-25-2010, 05:43 AM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
You never see what is around you ;-) That is magic of human sight with brain preprocessing ;-) You cannot rely on your sight while taking pictures.

You pic still overblown. You have got chroma aberation on edges of window. First picture is good enough composition. Focussing attention of viewer to look out of window. I wonder what this picture tries to tell. I would rather go closer to window and captured nature around ( i guess that is centre of interest). Purpose of almost dark window would be channelling attention to nature. Your HDR picture is chaos for viewer. Nobody knows what to look at since there is too many distracting features. Viewers eyes will just travel accross the picture and then go to next one since they get bored by lack of interest in image. Art of light is about communicating emotion.

Unfortunatelly, last trend is mastering post-processing skills instead of basic skills (such as correct light, composition and so on). Looking uninteresting and boring. It is just an other picture taken by Jenny from next door with mobile/compact camera. Why bother by this sort of photography at all?
Forum: Digital Processing, Software, and Printing 10-25-2010, 05:23 AM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
exactly, that is most easy and most accurate way to expose right. This tricks is here from almost begining of the photography. It just got fancy name HDR with dawn of digital processing. Digital blending is there since begining of Photoshop. HDR SW/plugins is just result of laziness and misunderstanding of art of light.You take necessary number of shots covering whole dynamic range and then blend them in any post-processing program with use of masking, opacity, blend if and so on. I would say that it is much quicker than any HDR program. Still, you have got realistic look of properly exposed picture full control over any adjustment you desire.

RAW vs JPEG - there was a thread about it somewhere. Summary:

1. most cameras have got 10 or 12bit tonal range per channel. JPEG has got just 8bits. In other words 8b are 4096 tones of shade/color. 12b are 4096+2048=6144 tones of shadows/colors. Simply put, if you edit JPEG, you end up with 3EV of tones instead of full 5EV range. In case of RAW, you got 10EV of tonal range of sensor (in case of Pentax K-7). Once you edit RAW, you end up with 6EV (which is still out of limit of JPEG). All examples.

2. you don't need to worry about almost anything during the shooting since WB, contrast, local contrast, saturation and so on can be adjusted later on. one of myths about RAW says that post-processing takes too long. I don't know, setting camera properly to get desired JPEG takes same time or even more. Unless, you are "I have been there too" photograph, who shoots anything what moves and don't plan shots and most importantly cannot distinguish correct light condition necessary for at least good pictures (that is why most use HDR programs which somehow covers their incompetence)

3. RAW is for maximal quality. Fine art and so on. RAW is analogue data (FLOATING POINT values) whereas JPEG is INTEGER DIGITAL values. Any post processing (rounding and recalculating data) will cause quality degradation and in case of JPEG, posterization. I believe for most ppl is sufficient JPEG shooting since most post their images on web anyway.

As I have written in some thread regarding RAW work-flow. You start with ProPhoto RGB color space, 16bits per channel and 300dpi. Final degradation of the image(s) will be far better than starting with JPEG. After few adjustments, you end up with some painting-like image beyond recognition. Result will be over limit image and after final adjustments for printer. You get "perfect" picture with full tonal range of 5EV/8b (JPEG or any printer. photo papers are weakest link in reproduction).
Forum: Digital Processing, Software, and Printing 10-22-2010, 10:46 PM  
digiKam humiliates Photoshop in HDR Challenge
Posted By sniper29a
Replies: 61
Views: 19,971
HDR trick is modern trend of last of few years. wildly used by amateurs who still don't know what they do (and never will). Picture of beach is nice example. It is a picture from dream world, not reality. Perhaps it is some sort of art.

As newmikey says, insufficient dynamic range of SLRs, DSLRs is haunting pros for centuries. Result was was very simple. And used trick was taking as many pictures as necessary to cover whole dynamic range. Results of tone maping of HDR SWs (such as photomatic) is unrealistic dream picture.

Easier, most accurate way for me is take pictures with right exposure (exposed to right). Mask, them, adjust them as they suppose to be and then blend them. As landscape photographer. Dynamic range is very often problem for me and no HDR SW didn't give me satisfying result. Other than screwed up skies and unrealistic look.

Photomatix standalone/plugin (if anyone interested, i should sell it) is on my HDD for a year and used only in the beginning. Speed of processing seems to me same. Simply scenes are done quicker by PS, I would says. Difficult scenes are out of capabilities of HDR SWs. Generally, HDR may be good for lazy ppl with static scenes without any moving objects. Everything else looks bad (for me, maybe enough for most ppl).
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