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Forum: Pentax SLR Lens Discussion 08-09-2018, 09:23 AM  
Comparing DFA* 50mm with 50mm f2.8 MACRO
Posted By JBox
Replies: 35
Views: 2,111
@dofmaster
Just a point of clarification: Which 50mm f2.8 MACRO are you testing? I assume that it is one of the F, FA, or DFA?
Forum: Sold Items 03-26-2018, 09:20 AM  
For Sale - Sold: FA 24~90/3.5~4.5 AL [IF] Like New NIB/NOS
Posted By JBox
Replies: 4
Views: 476
PM sent.
Forum: Pentax News and Rumors 02-22-2018, 03:11 PM  
The official presentation (Ricoh) of the Pentax Mark II
Posted By JBox
Replies: 331
Views: 30,647
Indeed:
Forum: Pentax News and Rumors 02-22-2018, 11:42 AM  
DFA*50 1.4 coming
Posted By JBox
Replies: 3,156
Views: 265,556
I will re-post this since it has gone largely unnoticed. It appears that the DFA* 50 was used for some of the sample images for the K-1 II:
Forum: Pentax News and Rumors 02-21-2018, 07:03 PM  
DFA*50 1.4 coming
Posted By JBox
Replies: 3,156
Views: 265,556
Go to the page here for K-1 II sample images. The last few images claim to have used the lens "HD PENTAX-D FA*50mmF1.4 SDM AW". Below it says: "The lens used is Beta version, and the name is tentative."
Forum: Pentax News and Rumors 02-21-2018, 04:37 PM  
Ricoh announces an upgrade service for current PENTAX K-1 consumers
Posted By JBox
Replies: 258
Views: 19,111
This upgrade option is probably one of the more interesting things about this K-1 II release. Does anyone know if other camera makers have done a hardware upgrade like this before?

I wonder if they will transfer the camera specific info such as serial number, shutter count, manufacture date, etc. to the new main board?
Forum: Pentax SLR Lens Discussion 01-18-2018, 07:28 PM  
A new kind of lens oddity?
Posted By JBox
Replies: 3
Views: 750
The duplicated marks you see in the head-on shot are reflections. In that picture I believe that the inner most marks are the direct view and the outer marks are their reflections.

I guess it could be blackening. Regardless of what exactly it is, it seems to beg the question about whether the lens is been worked-on in the past. The lens has some wear, but I don't see any direct evidence that it has been disassembled. I have also wondered if the glue/sealant/blackening could have worked itself out of where it is supposed to be due to temperature extremes?
Forum: Pentax SLR Lens Discussion 01-18-2018, 06:01 PM  
A new kind of lens oddity?
Posted By JBox
Replies: 3
Views: 750
I just received an FA 20-35 that I bought, and I noticed something right away that I have not seen before or heard about as a type of issue. There seems to be some glue or sealant around the inside of the front element that is not evenly applied. This can be seen by looking from the front, but mainly by looking at the front element from an angle. There are also a few spots of the substance that are not connected to the bead around the edge. See pictures below. Has anyone seen this kind of thing before? I am not sure that it is even a problem. I have not taken many test shots yet. I am mainly wondering if it is indicative of some larger issue. :(

Thanks for any insights.




Forum: Pentax K-1 12-12-2017, 03:04 PM  
White dots in images taken indoors at exposures 1/25 through 1/10 sec. at f/2.8
Posted By JBox
Replies: 50
Views: 3,042
Would you be able to post your raw test images that you have so far? I would like to compare them to my tests. I had my K-1 calibrated by Precision last year for the white dot issue. I saw improvement over its initial performance, but lately I have been hearing things that are making me think it is still not on par with the best performing K-1's. :(


I would be interested to see longer test images as well. :)
Forum: Pentax K-1 09-07-2017, 05:41 AM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
I would very much appreciate it if you could. I think it would be very helpful for @awscreo and I to have your test images to compare to our tests.
Forum: Pentax K-1 09-06-2017, 07:34 AM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
I got around to doing some test images last night. I did a sequence of 3 at ISO800, then 2 at ISO100, and finally another at ISO800. I did a map pixels between the two ISO100 images. That removed some of the obvious hot pixels, but not any of the noise that we are concerned with. See the sequence here. A number of the images are mostly light because clouds kept moving through. My K-1 was reporting a few degrees higher temp, but they all still look pretty bad by comparison. I have not done any LE stuff since I had it calibrated around a year ago. I guess ignorance is bliss after all. :(

@MJKoski
Would it be possible for you to post 4 minute ISO100 and ISO800 examples from your second K-1? It would be really good to get some kind of baseline in this thread.
Forum: Pentax K-1 09-01-2017, 03:04 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
It would also be useful to know if shadow or highlight correction were on for the test image.

If I have time this weekend, I will try to get some similar images to use for comparing.
Forum: Pentax K-1 09-01-2017, 12:55 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
Yes. See my posts here and here. One of the post-calibration dark-frames from my camera was also used in @MJKoski's comparison image in this tread.

However, looking back in this thread, it seems that your K-1 compared favorably to all others including mine post-calibration. Thus, I am not sure how much improvement you can expect to see. I am not sure how to compare to the image you just posted since it doesn't have the exposure info metadata. I can maybe do a dark-frame with mine if you can provide the exposure info for it. I would need at least ISO and exposure time.
Forum: Pentax SLR Lens Discussion 07-18-2017, 03:47 PM  
FA* 85 f1.4
Posted By JBox
Replies: 21
Views: 1,484
+1 for the A* 85.

1. I do not own the FA* 85.
2. I have not owned it.
3. For 85mm, I thought about the A* first and ended-up getting that.
4/5. Now that I have the A*, I have not really given much thought to the FA*. The A* meets all my needs in the 85mm department.
Forum: Sold Items 05-18-2017, 09:59 AM  
For Sale - Sold: SMC K 28mm f/2.0 28/2 [Zeiss 'Distagon'/'Hollywood'] [w/ optional dedicated hood]
Posted By JBox
Replies: 14
Views: 1,543
First of all, PM sent.

Secondly, from the linked info, it seems that the most recent Zeiss ZK/ZF2/ZE versions of the 28/2 would fall under the diagram labeled "Zeiss-Cosina Distagon 28/2". Is that correct?
Forum: Sold Items 03-18-2017, 03:57 PM  
Wanted - Acquired: Pentax A* 85 f1.4
Posted By JBox
Replies: 4
Views: 309
Manish is having second thoughts about parting with his, so I am looking again. Please let me know if you have one!
Forum: Sold Items 03-16-2017, 09:58 AM  
Wanted - Acquired: Pentax A* 85 f1.4
Posted By JBox
Replies: 4
Views: 309
Looking for a good condition A* 85 f1.4, preferably with the original MH-RA hood included. Must be fully functional and optics must be in very good condition with no scratches or haze. I am willing to consider a number of external/cosmetic conditions. I will pay up to $1100 USD (depending on the condition) and buy from anywhere, but seller must be able to ship to Michigan, USA. If you've got one you are willing to part with, please let me know!

Jeff
Forum: Troubleshooting and Beginner Help 12-10-2016, 12:01 PM  
Formal process to suggest product and/or firmware update ideas?
Posted By JBox
Replies: 3
Views: 613
Great! I, and no doubt others, will be sending our ideas your way!
Forum: Troubleshooting and Beginner Help 12-09-2016, 06:15 AM  
Formal process to suggest product and/or firmware update ideas?
Posted By JBox
Replies: 3
Views: 613
As you may have noticed, there are very many product and/or firmware update ideas for Ricoh Imaging / Pentax on PentaxForums. Does Ricoh have plans to create a formal process to gather these ideas from customers? At the moment, there is an informal process where members of the PentaxForums staff will present some ideas from the forums to Ricoh reps at industry shows. It would be great to see a process that would allow more ideas to be presented and considered by the Ricoh Imaging / Pentax team.

Thank you for your consideration.
Forum: Pentax K-1 11-23-2016, 09:01 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
I just went back and found that I have not posted an ISO 100 dark-frame here (I had assumed it was one of the initial ones I had posed). Is that one of awscreo's dark-frames?
Forum: Pentax K-1 11-23-2016, 10:24 AM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
Just an FYI, that ISO 100 dark-frame is from before my K-1 was recalibrated, so it is likely there is even less noise at ISO 100 now. I can do another ISO 100 dark-frame if you are interested, but I will probably not be able to before next week.
Forum: Pentax K-1 11-21-2016, 05:24 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
I have uploaded another version of the ISO 25600 dark-frame. This time at a camera temp of 23C. It is the file "25600F30-2.DNG" in the same directory as before. I think there is a little less noise than the previous one, and interestingly the raw file is a little smaller too.
Forum: Pentax K-1 11-21-2016, 12:17 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
OK. I thought you were referring to the camera temp as recorded in the EXIF data. The 25C I gave for the dark-frame was the camera temp. I don't know what the actual room temp was.
Forum: Pentax K-1 11-21-2016, 12:13 PM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
This evening I will see if I can get a cooler version of that dark-frame.


The temps we are discussing are the inside camera temp which will be higher than the room temp. Starting from room temp will get you into the 20C range it seems.
Forum: Pentax K-1 11-21-2016, 11:36 AM  
K-1 white dot issue. ?
Posted By JBox
Replies: 512
Views: 41,385
I have posted the ISO 25600 dark-frame to the same directory as the others. The new file's name is "25600F30.DNG" The camera temp was a little on the warm side at 25C.
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