Forgot Password
Pentax Camera Forums Home
 
Log in or register to remove ads.

Showing results 1 to 25 of 75 Search: Liked Posts
Forum: Troubleshooting and Beginner Help 07-16-2021, 04:04 PM  
P645 A* 300 F4 EDIF Tube slop
Posted By jbensen8191
Replies: 5
Views: 343
Turns out much simpler than I expected. There's no mucking about around any glass elements so very simple and low risk work with a set of small JIS screwdrivers.

Roll up the focusing ring grip to reveal 4 screws accessible with focus at infinity, there are another set of screw holes just to the left of these but these are the correct ones for proper focus after assembly. Marked A in first image.

After removing the A-screws you can pull away the aft section of the lens, this includes the diaphram and rear lens group etc. The 4 screws holding the aft section to the diaphram section have all worked themselves loose. marked B in second image. Simply tighten them up with a tiny dab of nail laquer should keep things snug for a while.

reassemble in reverse order align everything along infinity mark.
Forum: Post Your Photos! 07-02-2021, 01:43 AM  
Black & White The Darkest hour at Stiltsville upon Biscayne Bay!
Posted By henrikpedersen33
Replies: 7
Views: 850
He has been sitting there for quite a while ?
Forum: Pentax Q 05-14-2021, 05:09 PM  
03 Lens: Focus lock helper
Posted By K10Perry
Replies: 66
Views: 11,306
If anyone wants one or two, just PM me! I had to do a design update and there's a color change, but they still work just the same. Let me know...
Forum: Ricoh GR 05-22-2021, 01:22 PM  
The Good, the Bad and the Ugly
Posted By Vendee
Replies: 18
Views: 1,362
Nope.... your post and link were titled "The Good, the Bad and the Ugly". As pointed out, there was no "Good" in your post or your link. It is misleading.
Forum: Pentax SLR Lens Discussion 10-09-2020, 02:59 PM  
Created a new vintage lens reference site for major SLR lens systems
Posted By nklein
Replies: 20
Views: 1,588
Hey all,

I'm a web engineer who was laid off for a bit this past spring due to COVID, and used that time to create https://aperturepedia.com, a new lens reference site which I wanted to share with you all. My goal here was to create a free resource with long-term support for referencing and comparing specs for most vintage first-party SLR camera lenses, as well as a repository for helpful links to other sites which may not immediately come up in Google, or Wayback Machine-cached dead sites (RIP Geocities).

Right now the site includes OEM lens tables for the following systems:

- Pentax K
- Pentax M42
- Pentax M37
- Minolta SR
- Nikon F
- Canon FD
- Olympus OM
- Konica AR

Each lens table features expandable rows with more info and helpful links to other sites including reviews, repair guides, & more source material for each lens. The site itself is open source, anyone interested in checking out the source code can do so here: GitHub - nklein1/aperturepedia: Guide to first-party vintage SLR lenses

I've been following PentaxForums among other camera forums for a while, ever since I inherited my grandmother's Minolta XE-7 and discovered I could also adapt her Rokkor lenses on my Sony A7II. I found Dennis Lohmann's lens reference table (www.minolta.eazypix.de/lenses) extremely useful while I was investigating how to expand my Minolta lens collection, but wished that similarly comprehensive lens tables existed for other systems so that I could compare lenses at a glance.

As the site's still in its infancy, I wanted to reach out to you all to see if you had any thoughts about new features, information, or corrections which would make it more useful, or are interested in collaborating. I'm also actively seeking more links to add to the "Helpful Links" pages I've created for each system.

Hope you find it useful!
Nick
Forum: Pentax Price Watch 03-16-2021, 07:47 AM  
HD Pentax FA 35mm F2.0 Amazon Warehouse $207.53
Posted By Jonathan Mac
Replies: 21
Views: 2,256
It's a really great little lens, enjoy
Forum: Pentax Price Watch 03-16-2021, 06:48 AM  
HD Pentax FA 35mm F2.0 Amazon Warehouse $207.53
Posted By reduno
Replies: 21
Views: 2,256
Glad to hear the lens itself is in great condition, both physically and optically. Thanks for providing the feedback and enjoy your new lens.
Forum: Pentax SLR Lens Discussion 02-17-2021, 06:45 AM  
What is the purpose of the 15mm limited?
Posted By UncleVanya
Replies: 210
Views: 11,757
Image sensor format - Wikipedia

It is based on how video cameras tubes were named.
Forum: Pentax SLR Lens Discussion 02-12-2021, 09:38 AM  
Full-frame vs. cropped lenses on APS-C camera
Posted By normhead
Replies: 184
Views: 7,743
My wife is into photography and steals my favourite lenses for her own use. You have no idea how lucky you are.

Most lenses are sharpest in the centre and weakest on the edges, so the crop will use the sharpest part of the FF lens.

Canon EF 35mm f/1.4 USM L II on 24 MP APS-c



Canon EF 35mm f/1.4 USM L on 21 MP FF


I know these are not exactly the same lens, but it illustrates what I'm talking about.
Look at the FF edges compared to the APS-c wide open. The APS-c cuts off the worst part of the image. And the end results are very close in terms of utility.


For the most part FF lenses do very well on crop sensors. When you look at my DA*55 1.4 and DA*60-250, some crop sensor lenses also do very well on FF. It's more about the lens and the size of the image circle, than it is about what they were designed to go on. The DA*200 was never redesigned for APS-c. It went from being an FF lens in earlier incarnations, to being a crop lens, then back to being an FF lens, with very little modification in the various incarnations.

I you want the best edge to edge performance an that is worth more to you than the extra resolution, 1.4 (or even ƒ2) on APS-c is the superior image.

If you think about it, if I mounted the above lenses on my Q-S1, 1:2.3 sensor, only using the very centre of the lens, it would be by far the most consisted edge to edge, and possibly the sharpest image.

The edges on most FF wide angle lenses are extremely problematic wide open.
Forum: Pentax SLR Lens Discussion 02-12-2021, 09:36 AM  
Full-frame vs. cropped lenses on APS-C camera
Posted By volley
Replies: 184
Views: 7,743
I'm afraid you are wrong - well actually I'm happy you are wrong, because I can use my favorite FF lenses without hesitation on FF and APS-C bodies.
What makes you believe a FF lens would have a different resolution depending on the sensor format? The capture with an APS-C sensor just records the "best" i.e. center portion of the image projected by the lens.
Forum: Pentax SLR Lens Discussion 02-01-2021, 07:20 AM  
Check you old lens carefully!
Posted By Darkover
Replies: 22
Views: 2,913
After 2-3month I found that my repaired lens showed a problem. There happens some bubbles between
the two glued lens. :fedup:

So I open it again. This time the lens stayed over night in acetone, but that did not work. Than I put
it for a hour in a thermos-bottle with cooking water. That works and I had two lens again.

I invented a part to put the two lenses in the correct position and printed it:

Attachment 524060

I ordered a special UV Glue from internet that I used now:

Attachment 524061

I cured it with an UV led for a few hours and waited another day before I install it back in the lens.
Now the lens looks like new. I hope this time it will work. :hmm:

Olaf
Forum: Pentax SLR Lens Discussion 01-18-2021, 11:02 AM  
Pentax-DA 35mm F2.8 Macro auto focus weakness
Posted By aslyfox
Replies: 24
Views: 1,393
interesting

this article does discuss the SMC version




Read more at: Full Frame Coverage of DA Lenses: Comprehensive Test - Gear Guides | PentaxForums.com
Forum: Pentax Q 07-30-2020, 07:51 PM  
Pentax Q-7 with external turret viewfinder
Posted By 2old4toys
Replies: 7
Views: 1,351
Forum: Pentax Q 04-13-2019, 09:13 AM  
Pentax Q for astrophotography beginner?
Posted By geo444
Replies: 84
Views: 18,682
.
220° Lens for the Pentax Q ?
4.2 mm Image Circle, more suitable for 1/3"-1/4" ?
At 2.1 mm from the center =~ about 37° Oblique Rays on the Pixels ?!
in the imx144 Specs, Sony measures Oblique Rays = 0-20°
and =~45° on the Protective Glass !?
.
Thus you'll have to Cut its IR-Filter-Box at less than 2 mm from the Sensor's Protective Glass !
... If you suppose the Sensor's Protective Glass to be 0.6 mm Thick :
http://mecastronics.free.fr/PentaxQ10AstroIR.html
( = the thickness of the IR cut Filter )
.

.
In the Kayak World, that wouldn't be too hard to get some friend lend you his Action Cam ?
One with 12 MP 1/2.3" sensor and the capability to record a Raw File...
... so you could evaluate the Aberrations ?
Especially the - Red Side - Chromatic Aberrations...
.
Can't wait to see the results...
;)
Forum: Pentax Q 07-19-2020, 07:57 AM  
Pentax Q for astrophotography beginner?
Posted By 2old4toys
Replies: 84
Views: 18,682
Given how Hong Kong has less than ideal conditions, as a novice 1st timer, I am pretty chuffed with this early result. Can make out the Milky Way from the raw file, shot with my Pentax Q-S1 and 02 standard zoom at its widest. ISO400, 30 second exposure aided by the Sightron nano.tracker.
Forum: Post Your Photos! 04-07-2020, 01:47 PM  
Night Super Pink Moon
Posted By LennyBloke
Replies: 4
Views: 413
Handheld, quite a bit of PP....

Forum: Pentax Q 03-21-2020, 08:53 PM  
Soratama for Pentax Q
Posted By 2old4toys
Replies: 26
Views: 4,139


Tokyo
Forum: Pentax Q 03-09-2020, 01:20 AM  
Body Change from Q-S1 to Q Original
Posted By pid
Replies: 13
Views: 1,411
Thank you for those great Informations! ... “That’s one small step for a Pentaxian, one giant leap for Pentax Q.” ;-)

I can't wait to see when the first transplant will take place
Forum: Pentax Q 01-21-2020, 09:35 PM  
Soratama for Pentax Q
Posted By barondla
Replies: 26
Views: 4,139
Pentax Q7 with 72mm Soratama lens. 1st attempts. So far the Q is easier to use than the K-1.
Thanks for looking,
barondla
Forum: Pentax Q 11-28-2019, 02:28 PM  
Soratama for Pentax Q
Posted By jumbleview
Replies: 26
Views: 4,139
Pentax Q-S1 + Pentax Q-K adapter + Sigma 24 MM Wide II Macro + 72mm Soratama
Forum: Pentax Q 03-03-2019, 01:05 AM  
Fish-Eye Options for the Q
Posted By 2old4toys
Replies: 31
Views: 5,238
The store I bought it from mislabeled the Fujinon 1.4mm F1.8 as a CS, Fujinon 1.4mm f/1.8 Fisheye lens CS Mount DF1.4HB-L1 - Ideal for All Sky Camera but to my delight it’s actually a C mount lens! Simply mounted it with the same inexpensive one piece C to PQ adaptor as I already used for my Funjinon 2.7mm F1.8. I can even employ the same rubber O-ring as a variable thickness shim for re-focusing from zero to infinity! Outwardly the dimensions match the 2.7mm F1.8. Without the labels, you could not tell them apart. The sturdy plastic lens cap came as a bonus that fits my 2.7mm F1.8 lens too! I wish I had spare. The accompanying simple rear cap is nothing to write home about but appreciated still.

Confirmed my suspicions that it’s a full circular fisheye image on a Q-S1 (what I wanted), and a gives a cropped-circle image when pairing with my original Q. How much crop off the top and or bottom varies depending on the stabilization compensation and your C to PQ adaptor’s alignment.

Resolution I consider is still on par with the 5 MP 2.7mm F1.8. It also exhibits similar purple fringes in very high contrast situations but I am able to rein them in with a few sweeps of a finger via Snapseed, the sample below was cleaned up this way.

Field of view is certainly more than the 180,
I am not sure how to measure how wide exactly but I guess 190 or more.

If you want a fast fisheye that fills the frame on either the smaller or larger sensor Q’s without a black circle, the 2.7mm F1.8 is great.
If you are after the extreme look of a full circle super fisheye for the Q7 or Q-S1, this is a neat and perhaps at this moment, even unique proposition. £65 inclusive of postage within the UK, is not outrageous IMO.


Funjinon 2.7mm F1.8



Funjinon 1.4mm F1.8


What do you think?
Forum: Pentax Q 02-21-2019, 11:21 PM  
Fish-Eye Options for the Q
Posted By Abbazz
Replies: 31
Views: 5,238
For the Q, the Entaniya M12 280 would be more useful with an image circle of 4.2mm, as well as less ponderous (175 g) and much easier to obtain. And its field of view is even better than the Lens Rentals contraption: 280 degrees!

Cheers

Abbazz
Forum: Pentax Q 01-22-2019, 05:56 PM  
Fish-Eye Options for the Q
Posted By 2old4toys
Replies: 31
Views: 5,238
Some protection for my Fujinon fisheye. Added a strip of black card to deepen a black plastic push-on cap standard 55mm. Will be more more robust once I find some scrap black plastic material to replace the cardboard 😅


Forum: General Photography 01-21-2019, 10:13 AM  
there is a lunar opportunity that won't come around for a while if you miss it
Posted By robgski
Replies: 54
Views: 4,976
During the eclipse, I had some fun with the K-5 and the Rokinon 8mm Fisheye [IMG]High Overhead by Rob Gutkowski, on Flickr[/IMG]
Forum: Pentax Q 01-19-2019, 12:41 AM  
Fish-Eye Options for the Q
Posted By 2old4toys
Replies: 31
Views: 5,238
I needed a shim between the Fujinon fisheye and my one piece C mount to Pentax Q adaptor.
Re-using the black rubber o-ring seal from the silver metal adaptor out of the Axis security camera was very handy. It is offering just the right flex to allow for smooth focus adjust with enough resistance that stays put when I want it to. Acts like a makeshift helicoid I suppose. Give it a try if you did not throw out your o-ring already. Otherwise a similar size o-ring would do the trick.

Search took 0.01 seconds | Showing results 1 to 25 of 75

 
Forum Jump


All times are GMT -7. The time now is 03:46 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top