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Forum: Pentax K-1 10-06-2019, 04:31 AM  
Post your K-1 pictures!
Posted By Pikselisiirto
Replies: 27,939
Views: 2,447,272
Dfa*50
Forum: Pentax K-1 07-24-2019, 05:02 AM  
Post your K-1 pictures!
Posted By Pikselisiirto
Replies: 27,939
Views: 2,447,272
DFA*50

Forum: Pentax K-1 07-23-2019, 03:54 AM  
Shutter shock with small primes
Posted By Pikselisiirto
Replies: 62
Views: 4,900
My K-1 with DFA*50 produce shutter shock blur from 1/200s - 1/320s and slower. It is worst at 1/160s and slower. I cannot use IBIS because it would be pointless to use DFA*50 then. Guaranteed maximum sharpness basically means that electronic shutter must be used when going below 1/400s. Pentax included single shot ES, but it does not work with the optical viewfinder. My solution is to use hand-held pixel shift and pick one photo later on. It is impossible to check those photos on the field, so first I shoot one photo and then try to do identical composition with pixel shift. It is unfortunate that all this crap has to be done to get maximum performance with all shutter speeds. Pentax could help a bit by giving optical viewfinder for single shot ES and allow to select custom shutter speed range for ES and mechanical shutter.
Forum: Pentax K-1 07-03-2019, 02:34 PM  
Post your K-1 pictures!
Posted By Pikselisiirto
Replies: 27,939
Views: 2,447,272
Forum: Pentax K-1 07-02-2019, 03:29 AM  
K1 - Pixel Shift & Bracketing - Question
Posted By Pikselisiirto
Replies: 16
Views: 4,681
If you do pixel shift, there is no better editor than Rawtherapee. Motion is fixed by using a single photo for those parts. Basically I prefer Rawtherapee for all K-1 stuff. Very natural starting point with built-in K-1 profile and do not require much to get natural looking photos.

Pentax fcked up their pixel shift a bit, if you want to bracket. Slow card writing adds several seconds delay between brackets. Camera buffer could hold up to four pixel shift photos before card writing is necessary, but Pentax did not incude that option. You have to manually set different shutter speed for another pixel shift shot, if you want to bracket. This does not add extra delay because card writing takes several seconds anyway...


Successful pixel shift stacking adds at least 1 EV worth of dynamic range, so if you need to include more highlight details, -1 EV compared to normal shooting is okay.

There is another use for pixel shift. I use it when shutter shock is a problem. Optical viewfinder shooting is possible with PS, but Pentax denied that when using ES...It is extra pain to extract one photo, but at least I get to choose from four photos. Gives a bit more security against hand shake blur. This means that if you want always 100% sharpness from the camera, IBIS is only useful for pixel shift. Well, the camera is still the cheapest by far for my needs even with gimped features.

Pentax released SDK for those who want to write camera control software. I do not know, if there is commands which could force to queue pixel shift shots in the buffer. Focus bracketing should be possible. Someone actually did it and released it here somewhere.
Forum: Pentax K-1 06-20-2019, 11:37 AM  
Post your K-1 pictures!
Posted By Pikselisiirto
Replies: 27,939
Views: 2,447,272
DFA*50 F5.6

Forum: Pentax News and Rumors 06-19-2019, 03:12 AM  
New Sony APS-C Sensor - 26MP
Posted By Pikselisiirto
Replies: 1,219
Views: 89,744
I wonder why it is so hard to make a hybrid. Basically every DLSR is mirrorless when you are using back screen. Then it just needs electrical pixel matrix overlay on the OVF which changes from transparent to a visible pixel screen. This tech probably does not exist or is expensive now. Other solution would be two viewfinders. Personally I would like to have an external EVF which you wear like a monocle. Looks ridiculous, but sooo practical because camera placement does not matter then. These photographers would be like pirates with one eye covered. External EVF just needs HDMI stream and maybe some tweaks to HUD which can be done with firmware update. Yes, mirrorless need good AF too, but for video it does not matter much. Mainly for action and then you can use...well OVF.
Forum: Pentax SLR Lens Discussion 06-16-2019, 01:31 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
Got the lens back from the service. Took almost a month. First it went to Sweden and they sent it to Germany. Service report reads that they did focus point adjusment and optical check. Now those soft edges are much better. Still it feels like that my copy is not quite 100% what it should be because top edges have more sharpness than bottom edges. I tested it with F2.8 for infinity focus sharpness. Not really using that much those wide apertures for infinity focus though and closer focus distances do not produce that obvious differences what I have seen. Center area is really sharp and there it seems to perform 100% and top middle edge is quite close. That is probably the intended quality for all edges.


A bit shame that premium lenses can have sloppy quality control. What I learnt from this that I do not trust anything what manufacturers say about premium quality control. Finnish shops have 14 day return policy for web purchases, so I will do these tests first no matter what brand or price it is.

Here is some comparison shots. Right top image is the worst edge before service which is left bottom edge. Left image is the same after service. Left bottom image is the best edge which is top middle edge. Right bottom image is right top edge which shows how much better that corner performs compared to worst corner. These are 100% crops.

Forum: Pentax News and Rumors 06-15-2019, 05:44 AM  
New Sony APS-C Sensor - 26MP
Posted By Pikselisiirto
Replies: 1,219
Views: 89,744
Staying with DSLR or releasing a hybrid is probably the best bet for Pentax. Many other brands have so much resources and reputation that Pentax can't compete with everything. Basically K-1 and K-3 II / KP raised Pentax from the ditch because they have many good features with bargain price. Pixel shift as a leading feature for Pentax had it moment, now Panasonic S1R/S1 doing it better. I can see why K-1 has bargain price because it has quite old sensor, but tuned to compete with newer sensors. Video recording is below mediocre, slow SD-card writing and shared with two slots. Tricky AF and not great continuous shooting speed, shutter shock problems. They had to cut from somewhere to reduce price. Hopefully Pentax does similar things in the future and compete with value. They should focus more on firmware features because phone cameras are leading there and other camera brands not doing much either. I would wish to have scripts as custom functions. You could chain low level commands and the camera execute them as fast as possible. It would solve many problems for me. Pentax really doesn't have same professional camera equipment line as major brands, so no real reason to make artificial software blocks.
Forum: Pentax Full Frame 05-28-2019, 04:41 AM  
Pentax K1 Dynamic Range Question
Posted By Pikselisiirto
Replies: 12
Views: 1,644
I'm using UniWB custom white balance, so that live view histogram is very accurate for RAW photos. Then it is easy to change exposure to saturate ISO 100, if enough light. Usually I keep checking left side of the histogram until it has first high spikes at the edge. Then I know that K-1 dynamic range has been maxed out and therefore exposure has been optimized.

I posted a photo to K-1 image thread here and it seems to have pretty much maximum dynamic range this camera can do. It is also pixel shifted, so it adds at least 1 stop or a bit more. Nice bonus when pixel shift itself is successful



This is what Rawdigger shows for one photo. Yes, it looks very dark because I squeezed every drop of highlight detail I could without getting visible shadow noise.

Forum: Pentax SLR Lens Discussion 05-17-2019, 01:42 PM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
Are you guys really looking test image at full resolution which is 1458x1458? There is nine photos and each is 486x486 at 100% crop pixel level. I did this so that the forum would not resize the image, but it still does that, if I'm logged in. Must be my personal settings. Image can be opened in separated tab to view at 100% then.

For me, varying softness is obvious. If I label each photo like upper row is 1,2,3, middle row is 4,5,6 and botto row is 7,8,9, then I see that only 2 and 5 are excellent. 7 is worst, then 9 and 8

I am full aware about how weather conditions can affect sharpness. These same edges always are worst, no matter how many times I shoot and no matter what conditions. It gets worse when opening aperture more. At F5.6 it is quite minor problem and at F8 pretty much gone. That would be expected from a lens which would cost like a hundred bucks or less. Not from a lens which costs a grand.

If excellent sharpness can not be obtained at infinity in every edge but only some, what is the point testing in closer focus? The lens is unacceptable anyway then. Haze would be visible in every part of the lens. It should be obvious. I have shots at F1.4, F2.0, F4.0, F2.8 from this same place. Same problem edges everytime.

And BTW, the first copy did not have this problem, when I checked couple old photos. It had cosmetic issues like small white spots inside the lens barrel and importer agreed to give another copy when I sent photos from those spots. It feels like I should had kept that even if those white spots look annoying and might produce a bit flare in extreme situations. It just leaves bad taste when you spend that much money and then see flaws, first cosmetic and now optical flaws.
Forum: Pentax SLR Lens Discussion 05-17-2019, 03:08 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
Those photos have been focused to the infinity with live view contrast AF at the center. All subjects should be in perfect focus because they are very far like two kilometers or so. No refocusing between shots. I used more cloudy weather to reduce CA, so that sharpness is more clear. Infinity focus makes sure that camera reposition does not change focus range at all. I use infinity focus a lot, so if there is problems, closer focus range does not matter. This lens should be excellent in all focus ranges. I'm starting to think that this lens produce normal sharpness only at the center and top middle edge. Then it would be excellent, if top middle edge sharpness happens in all edges.

I have already sent the lens to the Sweden for checking. If they think that this is normal Pentax peformance, I probably sell the lens and the camera. These quality issues are just ridiculous because I already sent first lens and got decentered one back. Then the camera also has obvious shutter shock issues starting at 1/250s and slower. That one I can avoid with ES, but it makes IBIS useless. My older Nikon D3200 camera had zero problems.
Forum: Pentax SLR Lens Discussion 05-14-2019, 02:37 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
Very excellent indeed. Here is at F2.8 and 1/1600s. Somewhat cloudy weather. The thing is that top middle edge is so sharp and almost same as center, but all other edges are very soft in comparison. Top right edge and middle right edge are second best and the rest are just mess. I'm sending this sample image to Pentax service and see what they say. It would be absurd to think that this is a good lens.

Please, open the image to separate tab if you cant view it at 1458x1458. Same thing can be seen with F4.0 I posted before, but it has less softness.

Forum: Pentax SLR Lens Discussion 05-09-2019, 04:49 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
Here is nine shots at F4.0 and 100% crops, focused to infinity, no refocusing between shots and same exposure settings. Upper left photo is upper left corner, etc.

Forum does not show full size. You need to view the image in a tab and zoom to 100%. Resolution is 1458x1458


Strange thing is that upper middle is sharper than bottom middle.Looks like this lens has some flaws on left middle corner, left bottom corner, bottom middle and right bottom corner :fedup: Those problem areas have more CA too. No post-processing corrections.

Forum: Pentax K-1 04-30-2019, 05:15 AM  
Live view focusing
Posted By Pikselisiirto
Replies: 1
Views: 915
Why there is a black rectangle restricting focus point movement to the edges? I also have focus accuracy problems with CDAF (should never happen?) when the subject is near edge and is not parallel enough. K-1 shows green box for CDAF, but I can still make sharper focus manually! I noticed this when trying to shoot edge shots for decentered lens test with the DFA*50
Forum: Pentax SLR Lens Discussion 04-27-2019, 06:59 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
It is just a test image and it was calm weather. Shutter speed was like 1/5000s so no motion blur.

Here is another example. Sorry, not something you asked, but I started notice these in old photos. This is pixel shifted and F5.6, so I think the difference is obvious, but I don't know warranty tolerances. When infinity focus is sharp, it seems to only happen then. Closer focus not so obvious.

Left is right middle edge and right is left middle edge. 100% crop.

Forum: Pentax SLR Lens Discussion 04-27-2019, 03:29 AM  
Decentered DFA*50?
Posted By Pikselisiirto
Replies: 28
Views: 1,825
These are 100% crops and F1.4 aperture. First is left edge and second one is upside down left edge. Softness can been seen from 1/4 of the left side when watching original resolution photo. I'm thinking to send it to the warranty, but they have strict rules that if they think it is fine, I have to pay checking costs and shipment. Sounds a bit ridiculous considering the price of the lens.




Forum: Pentax News and Rumors 04-07-2019, 03:26 AM  
The Pentax K1 III might be close
Posted By Pikselisiirto
Replies: 332
Views: 48,193
Pentax K-1 is special because it is clearly the cheapest full frame camera which has major competitive features against much more expensive full frames. This does not come for free. K-1 has weak video, tricky AF tracking and slow card writing. Sensor is not as modern as what latest full frames have, but it has been tuned to match pretty close considering the price of K-1.

I seriously hope that Pentax keep its special way and not trying to create another clone full frame camera with price fighting. They don't have funds to do that. Instead, I recommend them to focus more on their in-camera software features which can be improved cheaper than getting latest hardware. Great value is the strength of Pentax digital cameras. It is shame that they stopped improving K-1 software and just throwed a bit vague SDK kit, so that users can make remote control apps for K-1. It is better than nothing I guess, but improving K-1 this way will be slow.
Forum: Pentax K-1 03-27-2019, 05:24 AM  
Highest acceptable ISO
Posted By Pikselisiirto
Replies: 22
Views: 1,621
Personally I try to avoid lighting conditions which do not allow me to expose enough to saturate ISO 100. This is simply because saturated exposure at ISO 100 offers highest possible image quality. Even more with successful pixel shift. It is a bit waste because K-1 seems to be tuned towards higher ISO. I wish it had ISO 64 or lower, but still the best value camera out there for my needs. D810 costed almost a grand more at that time and it does not have pixel shift.


There is barrier when raising ISO is worser than software "gain" at lower ISO. When K-1 reach that barrier or is it just better to use highest possible ISO, if you can't expose enough?
Forum: Pentax K-1 03-17-2019, 04:37 AM  
Post your K-1 pictures!
Posted By Pikselisiirto
Replies: 27,939
Views: 2,447,272
Hitting the dew point produced some fog on the lake while the sun was setting.

K-1 and DFA*50 F5.6

Forum: Pentax K-1 01-28-2019, 04:25 AM  
Nice bit of promotion for the K-1
Posted By Pikselisiirto
Replies: 4
Views: 1,377
Pixel shift clearly is useful when fine details are combined with certain type of colors. Especially with detailed and colorful textiles. It produces sharper details and cleaner colors. I'm shooting mostly flat pictures and old items. Results can be so sharp with a DFA*50 1.4 than minor camera aligment compared to the subject aligment is visible as uneven sharpness. It give me headaches and I know that macro lens flatter focus area would be better here, but I'm not going to pay it from my own pocket. My lens might be a bit decentered too because slight softness happens mostly on the left side.
Forum: Pentax News and Rumors 12-24-2018, 08:44 AM  
DP Review puts K-1 Mark II as second worst camera of 2018
Posted By Pikselisiirto
Replies: 996
Views: 62,162
I don't know why Pentax doesn't give a choice to disable that noise reduction. It would had solved the problem. Sometimes the user might prefer to use it, so it is not like you paid for nothing when it is disabled. Forcing convenience features in this price category and target group is not a good solution, if better results can be produced without them.

Pentax K-1 is often seen from the wrong angle, but I can see why K-1 II is not that appealing especially when upgrading from the K-1

Dpreview seems to like cameras which can do everything well and don't give much value for cheaper specialized cameras which could even outperform other cameras in certain type of photos. Their review of DFA*50 indeed looks a bit suspicious because it still doesn't exist.
Forum: Pentax K-1 11-21-2018, 12:33 PM  
Spot metering doesn't work?
Posted By Pikselisiirto
Replies: 4
Views: 657
Live view highlight alert is a nice way to find the preffered exposure because you can see overexposure and live histogram. I tried to shoot the moon today in the dark, but couldn't change exposure the way so that the moon would not blink red at all. This is because EV metering bar was showing -5 all the time. I assume this was because of metering mode so that the camera tried to find good exposure for the darkness rather than the moon. Spot metering mode didn't do much. Spot metering should happen on the middle, but did nothing. Strange thing is that placing the moon to the bottom made everything except the moon darker in the LV, but metering was still showing -5 and I had to shoot an retry to find out exposure which doesn't overexposure the moon. I'm shooting RAW and using UniWB, so that highlight alert itself should be quite accurate. Also metering mode button did nothing when I pressed it in LV. Had to change the mode from the menu and it does show spot metering icon on the screen, but doesn't seem to work properly.

Is there any dark mode for the live view which use brighter exposure for the screen so you can see something, but use set exposure for actual photo? I usually just increase ISO a lot for composition and then set it back when done, but it takes time and is annoying. Could probably set high ISO for user mode, but they are already used for other things.
Forum: Pentax K-1 11-19-2018, 05:51 AM  
Has anyone tried scanning with pixel shift?
Posted By Pikselisiirto
Replies: 9
Views: 1,434
Sometimes it makes a difference. I would think that especially fabric photography could benefit from pixel shift greatly. Micro details can mess up accurate colors and hide details when using normal demosaicing methods.

This is 100% crop from a printed picture. These are JPG and imgur probably compressed them more.


Amaze demosaicing


Pixel shift

Forum: Pentax K-1 11-17-2018, 03:39 AM  
Electronic Shutter Exceptions (Bug?)
Posted By Pikselisiirto
Replies: 22
Views: 1,508
I use ES to avoid shutter shock blur below 1/200s and it requires LV mode. Many photos are focused to the infinity and with contrast detection to avoid calibration issues, so I don't use focusing when doing hand-held composition through the OVF, holding camera still, pressing LV and then ES is used when pressing shutter button. PDAF focusing has been very rare for me unless trying to focus close on something which moves all the time. Calmer subjects focus fine with slower contrast detection or I just manually focus with peaking. Mostly this is done with a tripod, so pixel shift is used anyway. K-1 and DFA*50 can produce amazingly sharp photos without shutter shock and when pixel shift works well enough and careful focusing is used. Especially wide aperture isolation can look very natural. This all is quite narrow use of the camera, but it mainly fits to what I want to photograph and this is why I think that K-1 is excellent value. Luckily I can dodge most of the weak points of K-1, but it is not so convenient.
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