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Forum: Photographic Equipment for Sale 10-05-2020, 12:25 AM  
For Sale: Very clean Pentax DA 35 f/2.4
Posted By dewolf
Replies: 3
Views: 739
Recently got one from a forum member, is very clean.
But thanks anyway mate.
Forum: Post Your Photos! 09-24-2020, 01:43 AM  
Macro 35mm asahi lens reversed on a K3 samples
Posted By dewolf
Replies: 4
Views: 273
Thanks K2 to K50.

Those were take with my K5IIs, I think.
Likely with the DA 55-300, a rather inexpensive lens but all the conditions were right.
And for the price my lens copy was quite sharp, especially at 300 mm.
Forum: Post Your Photos! 09-23-2020, 07:15 AM  
Macro 35mm asahi lens reversed on a K3 samples
Posted By dewolf
Replies: 4
Views: 273
Thanks mate.
I managed a little better this morning, less wind.
But me thinks at my age I better pull out a bit with a 50mm reversed.
I shake a bit lol.
Way to much tea... is there such a thing....
Forum: Post Your Photos! 09-22-2020, 01:08 PM  
Macro 35mm asahi lens reversed on a K3 samples
Posted By dewolf
Replies: 4
Views: 273
I found the 28mm to daunting to focus with as a macro / reversed lens, so I thought I would try the recentl;y purchased 35mm F2 Super Takumar.
It certainly allowed for further distance from the subject, and more light for focusing. Still pretty magnified though, But I needed a 35mm for my bag anyway.
Next I will hunt down a decent 50mm :)

Not terribly sharp due to lack of depth and wind, will try for better next time.

Enjoy.

dewolf's Album: 35mm reversed - PentaxForums.com
Forum: Photographic Equipment for Sale 09-16-2020, 03:16 AM  
For Sale: Very clean Pentax DA 35 f/2.4
Posted By dewolf
Replies: 3
Views: 739
deleted my reply. seems my proxy failed, sorry. I need a 35mm with aperture rings.
Forum: Troubleshooting and Beginner Help 09-04-2020, 01:31 AM  
sync cable size
Posted By dewolf
Replies: 6
Views: 513
Thanks Steve :)
Forum: Troubleshooting and Beginner Help 09-03-2020, 06:27 PM  
sync cable size
Posted By dewolf
Replies: 6
Views: 513
Godox TT600
The flash looks like a female phone plug mini. I may be wrong.

---------- Post added 09-03-20 at 09:29 PM ----------


in fact my headphone jack fits the hole in the flash, so I will assume its a 3.5 ?
Forum: Troubleshooting and Beginner Help 09-03-2020, 04:45 PM  
sync cable size
Posted By dewolf
Replies: 6
Views: 513
so which is standard ? 2.5mm or 3.5mm ? that seems to be the choice I have on B&H and amazon.
Forum: Troubleshooting and Beginner Help 09-03-2020, 03:16 PM  
sync cable size
Posted By dewolf
Replies: 6
Views: 513
First of all, the section for trouble shooting irony was not lost on me.
I often have trouble shooting, as is the case now.
I am going to be mounting my speed-light on a swivel that attaches to the hot shoe.
This means I will need a sync cable to power the flash.
Trouble is I can not find a place that defines which size cable I need for the Pentax K-3.
2.5mm or 3.5mm. As slow as shipping has been I would rather not buy the wrong size and spend weeks in the retun lane.
Thanks for nay help folks.

DeWolf
Forum: Troubleshooting and Beginner Help 04-08-2020, 03:37 AM  
to keep or return that is the question.
Posted By dewolf
Replies: 10
Views: 880
I had actually thought about getting a few images of my dog with a longer " distorted funhouse" looking nose, because as you say this is what wide lenses can do.
I guess you would need a fisheye lens for that.
I got quite close to my girl and tried a shot.
Although the pic was nice, it was not funhouse nice lol

see

https://www.pentaxforums.com/forums/members/64086-dewolf/albums/13550-astro/picture129969.jpg
Forum: Troubleshooting and Beginner Help 04-06-2020, 01:29 PM  
to keep or return that is the question.
Posted By dewolf
Replies: 10
Views: 880
Thanks folks, printed the return invoice and will mail it out wed, but have not found another copy for sale, so will wait
Forum: Troubleshooting and Beginner Help 04-02-2020, 12:04 PM  
to keep or return that is the question.
Posted By dewolf
Replies: 10
Views: 880
The camera was on a tracker, center stars did not streak. tracking was set for my location and GPS coordinates.
Forum: Troubleshooting and Beginner Help 04-02-2020, 11:17 AM  
to keep or return that is the question.
Posted By dewolf
Replies: 10
Views: 880
I recently purchased a wide angle Samyang 16mm F2 for wide field astrophotography.
I would also use it for close up images of my pets.
In the astro images I have found rather severe stretching of the stars on the left side of the image, and very little on the right.
I took about 50 shots and they all have the same stretching on the left.
I am aware of coma on wide angle lenses and although I see a hint of that on the right, the left just appears stretched.
Images of my pets do not see as sharp in the center as I am used to with my DA 100mm macro, or the DA* 300mm F4.
Could this be an element not centered ? should I return it ?
I am using live view with focus peaking for focusing on pets, no focus peaking on astro , just live view at max zoom.
I paid $359.00 new.
Should I accept this as the price is low ? is this what I should expect for a cheaper lens ?

Any suggestions helpful

https://www.pentaxforums.com/forums/members/64086-dewolf/albums/13550-astro/picture129909.jpg

This is the starfield image with the 16mm. sorry this is the largest I can post without a paid account

Here is a 100% crop from the left, you can see it gets normal as it flows to the right, after that everything seems the same.

https://www.pentaxforums.com/forums/members/64086-dewolf/albums/13550-astro/picture129910.jpg
Forum: Troubleshooting and Beginner Help 03-13-2020, 03:59 AM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
As an ending discovery, Rather than go through the motions they suggest to do a calibration, I racalled my phone has a compass, that requires me to do a figure eight held up to calibrate.
I did this with the k-3 for a few moments and got an OK. Not only that, I was able to track stars for 90 seconds with the 28mm, longest before that was 50 seconds.
Forum: Troubleshooting and Beginner Help 03-11-2020, 02:51 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
I installed Sky Safari on my phone, very nice app :) will hep me a lot when looking for targets, thanks. StellariumI have on the house computer.
Forum: Troubleshooting and Beginner Help 03-10-2020, 03:44 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
i remembered when I was young how to find it using the pointer stars.

This time of year it rotates my way rather late, and we have a lot of trees that block my view. but I know where in the driveway I have to be facing which tree to know where it is.
a lot of 100ft pines here and a rather large oak. basically a small forest behind and to the north of my house.My street faces west and most the roads near me are aligned roads.
Forum: Troubleshooting and Beginner Help 03-10-2020, 02:07 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
I am familiar as to where the north star appears here, out the front door and to my right lol. the directions i pointed were only close, i didn't use a compas. just based on the north star, sunrise and set. but, north port florida is the actual location
Forum: Troubleshooting and Beginner Help 03-10-2020, 12:33 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
OK so wherever CNP is at my location, it will move 1 degree away from its present location to the zenith for every degree I move the opposite direction.

I did 4 calibrations today, North, South East and West taking a picture after each calibration.
I do this because Exiftool will show the GPS data.

Number of satellites located after calibration to the north = 6, south = 7 east = 8, and west = 9.

Here is what the data looks like if this is of help.
Note, lines 16-17 seem inaccurate.

This is North

GPS Version ID : 2.3.0.0
GPS Latitude Ref : North
GPS Latitude : 27.086698
GPS Longitude Ref : West
GPS Longitude : 82.212920
GPS Altitude Ref : Above Sea Level
GPS Altitude : 13 m
GPS Time Stamp : 18:57:40
GPS Satellites : 06
GPS Status : Measurement Active
GPS Measure Mode : 3-Dimensional Measurement
GPS Speed Ref : km/h
GPS Speed : 0.35
GPS Track Ref : True North
GPS Track : 0
GPS Img Direction Ref : True North
GPS Img Direction : 0.15
GPS Map Datum : WGS-84
GPS Processing Method : GPS
GPS Date Stamp : 2020:03:10


and this is South

GPS Version ID : 2.3.0.0
GPS Latitude Ref : North
GPS Latitude : 27.086658
GPS Longitude Ref : West
GPS Longitude : 82.212863
GPS Altitude Ref : Above Sea Level
GPS Altitude : 12.7 m
GPS Time Stamp : 18:59:10
GPS Satellites : 07
GPS Status : Measurement Active
GPS Measure Mode : 3-Dimensional Measurement
GPS Speed Ref : km/h
GPS Speed : 0.81
GPS Track Ref : True North
GPS Track : 6.14
GPS Img Direction Ref : True North
GPS Img Direction : 183.5
GPS Map Datum : WGS-84
GPS Processing Method : GPS
GPS Date Stamp : 2020:03:10

---------- Post added 03-10-20 at 03:38 PM ----------



The smaller lens, 28mm is likely steel, everything else is aluminium as is the tripod .
Forum: Troubleshooting and Beginner Help 03-10-2020, 03:41 AM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
OK read it, totally befuddled lol. kinda. It seems that as we rotate on an exis and that tilt changes that there would be a time when Orion is more able to be photographed.
So many others can get long exposures without trails so I have to wonder if it is my geographical location that is the issue, or the time of the evening I am taking the shots.
I get better shots near the horizon and straight up. but in between those 2 areas I have trailing issues.
We have an entire week forecast to be pretty much solid clouds after sunset and during the day, so it might be a while before I get to do more testing.
I will read that link again, and also check for other online examples that may be more understandable to me.

---------- Post added 03-10-20 at 07:07 AM ----------



ok I read this
Astronomy Without a Telescope

makes more sense top me for some reason. And from what you have said 90 degrees is straight up " zenith", CNP is the opposite from where I am in Latitude from zenith.
Celestial equator is horizon or 90 degrees from CNP and crosses terrestrial horizon. Sp traveling a longer arc at Celestial equator means those stars seem to have a faster speed than do those at CNP. So I am guessing some times of the year when Orion is at its highest point is the best time to photograph . I hope that's right. lol.
But the GPS specs seem to say the opposite in regards to exposure time.
I apologize if you feel you are talking to a rock.
Forum: Troubleshooting and Beginner Help 03-09-2020, 06:00 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
I will definately read up at that link. I am sure most of it will go over my head, but I will read it over and over lol.
Before the clouds rolled in I had about 10 minutes to try the 360 degree calibration and take a few shots with the 28mm.
It actually did ok on orion, although to small to use, and straight up even better at 40 seconds. I calibrated facing North.,
Oddly enough I was never able to complete all the required movements for the calibration before I got a Complete notice.
Forum: Troubleshooting and Beginner Help 03-09-2020, 04:06 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
we hav a football field at the court house next to the Police Dept, but the lighting is blinding.

---------- Post added 03-09-20 at 07:09 PM ----------



"For a given focal length, the relative velocity of the starfield will determine exposure limits for the O-GPS unit."

But then again the old lens does not report its focal length, well at least it didnt used to lol, now it seems to accept input.

---------- Post added 03-09-20 at 07:14 PM ----------



But the time is repoted as being the longest time for exposure, so I would say that is a control. granted I can use a release cord and turn off timed exposure and go past the limit, or perhaps it will simply stop exposure when the time limit is reached. And that time limit changes with the focal length of the lens to a degree. 5 minutes for the 28mm and the 100mm, but 2 for the 300. How does it know.

---------- Post added 03-09-20 at 07:17 PM ----------



Oh BTW. I read an article today on calibrating this thing, and they suggested going 360 degrees. starting will roll, then pitch , and finally Yaw.
Getting a calibration OK used to take a minute or so facing north, Today I got the OK after 20 seconds or so by doing it 360 degrees.
But man is that a pain with a large strap attached lol.
IF we ever see the sky again I will test that out.

---------- Post added 03-09-20 at 07:23 PM ----------



by sweet spot you are saying thats the area where I am likely to get trails because of its unique position in the sky ?

Obviously Orion is the go to shot for a close nebula, a shame it also has to be the fastest star movement. However if I were to shoot when it is say 20 degrees position I would have better luck ?
Forum: Troubleshooting and Beginner Help 03-09-2020, 07:25 AM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
I do go over 180 each direction, but, the car is 15 ft away, so perhaps that. powerlines are about 100 ft away, no avoiding that here. Florida likely has little iron in the sane, I suspect more iron in the locals lol.
Finding a place where there are no powerlines around here means going somewhere unsafe, least in my neighbourhood.
What distance do you think I should be from a power line or car ?
I will drive the area and see if I can find an alternate location that is safer with no lines and little light..
Forum: Troubleshooting and Beginner Help 03-08-2020, 01:39 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
true that, it is a fussy thing, but sometimes the challenge is rewarding :)

Thanks for all the info mate :)
Forum: Troubleshooting and Beginner Help 03-08-2020, 11:17 AM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
well during a session it will change. If I start seeing trails and re-calibrate and they go away.
There is an acceptable drift in satellite orbit over their lifetime. It's usually small but it is there.
However that shouldn't affect the gps unit.
Atmospheric conditions in Florida alone could cause calibration issues. A signal passing through 90% humidity has to suffer a little I would think.
I wonder if the antenna on the unit could be modified to half wave from quarter wave or something lol, just me thinking.
I am always up for a good challenge but I would certainly need the papers on it and that is not likely :)
Eventually I will get a telescope mount for this purpose.
Forum: Troubleshooting and Beginner Help 03-07-2020, 10:32 PM  
O-gps1 and lens focal length discernment.
Posted By dewolf
Replies: 31
Views: 1,437
My thought would have been, that since the apparent movement of the stars against the earths rotation seems accelerated with higher powered lenses, then the gps would take that into account and accelerate the movement of the sensor.
But now I see it's the FOV that matters, and that for the camera, the sensor is always the same size and the same number of pixels. The only difference is as the subject gets magnified each movement is captured on a greater number of pixels and that the sensors movement would remain the same, but the time it took for it to transverse that smaller FOV would be less, resulting in a shorter exposure time for a 300mm as apposed to a 50mm, but I am curious as to how it comes up with the exposure time in advance before the shutter is pressed if it does not know what lens you are using.
somehow it can, as after calibration with a 28mm, I changed lenses and it knew somehow and shortened the exposure time.
Yup theres a mystery in that little addon lol.

---------- Post added 03-08-20 at 12:38 AM ----------



Interesting.
The manual says the compass determines or displays true north, not magnetic. so apparently the satellites report magnetic, the firmware translates that for the compass, but uses the original magnetic data for the actual photographic tracking.
The 45 degrees thing makes sense as I have found some objects leave little to no trail, while others seem to leave one regardless even after the calibration was done.
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