|
Forum: Pentax News and Rumors
01-30-2024, 07:51 PM
|
| |
| |
|
Forum: Pentax News and Rumors
12-18-2022, 07:11 PM
|
| |
| |
|
Forum: Post Your Photos!
11-01-2022, 02:53 PM
|
| |
| |
|
Forum: General Photography
10-19-2022, 06:35 PM
|
| |
| |
|
Forum: Pentax K-1 & K-1 II
09-28-2022, 01:34 PM
|
| |
Try this with the lens you already have: set your lens to 105mm and shoot a composite, stitching together many pictures. This will be sharper than landscape lens.
|
|
Forum: Pentax K-1 & K-1 II
08-09-2022, 02:18 PM
|
| |
I looked through a lot of SEC filings and market reports seeking information on profits on lenses versus camera bodies and I could find no support for that statement.
|
|
Forum: Photographic Industry and Professionals
07-29-2022, 07:10 AM
|
| |
I am interested in your lens design work. Modern glass catalogs lend themselves to different solutions than we had before, but it is expensive to add the low dispersion elements and sometimes more than the aspheres.
My last lens optimization put optical power near the sensor, which was particularly beneficial for a tight vignetting spec. That inspired this topic, since the mirrorless has a shorter distance to the sensor. However I had a look at mount to sensor distance in the mirrorless cameras and found it is not nearly as small as some of my designs. Is this due to fear of something hitting the sensor if it is too close to the front?
---------- Post added 07-29-22 at 08:19 AM ----------
Interesting. I suppose a lot of customers see the zoom as a good substitute for buying an array of primes.
I sold my 24-70mm when I realized most of my shots with it were at the extremes of the focal lengths. I have primes that serve me better.
|
|
Forum: Photographic Industry and Professionals
07-28-2022, 06:43 AM
|
| |
You design lenses too? I second your point here. I would also add that, from the quotes I get, low dispersion lens elements contribute as much to the costs as the aspherical elements!
|
|
Forum: Photographic Industry and Professionals
07-26-2022, 12:36 PM
|
| |
If Pentax is the only SLR maker, there will be no third party lenses. Pentax will have to follow suit.
Nikon and Canon are getting out of SLRs. The mirrorless cameras have a smaller distance between the lens and the sensor. Lens designers use that space when they can.
No new lenses will be designed with sufficient back focal length to accommodate the mirror of an SLR.
With no new third party lenses, won't Pentax fall behind?
|
|
Forum: Pentax K-70 & KF
07-05-2022, 08:17 AM
|
| |
| |
|
Forum: Winners' Showcase
07-03-2022, 07:17 AM
|
| |
I would like to nominate this photo
|
|
Forum: Pentax SLR Lens Discussion
06-16-2022, 10:11 AM
|
| |
If your lens has better resolution than the pixel size of your sensor, adding a teleconverter helps. It magnifies the image.
Otherwise, just tell your ff camera to crop, or crop in post.
Crop and teleconverter give you the same total light, since the latter just takes what would have been the cropped area and spreads the same light over a full frame.
|
|
Forum: Pentax SLR Lens Discussion
06-13-2022, 05:45 PM
|
| |
No, you get it back in sensor area.
Either the light is distributed over a small area with low f number or over a large area with higher f number. With the same field of view, the total light is the same.
Here's another way to see it, I have a 0.7 "reducer" that gets me more light because the full frame image captures a wider field of view. It converts my 2350mm f10 mirror lens into a 1650mm f7.
|
|
Forum: Pentax SLR Lens Discussion
06-13-2022, 03:23 PM
|
| |
| |
|
Forum: Photographic Industry and Professionals
06-12-2022, 08:51 PM
|
| |
I think that if I took a photo of someone's art work and sold that as my own, I would get in trouble.
|
|
Forum: Monthly Photo Contests
06-02-2022, 02:21 PM
|
| |
I would like to nominate this photo
|
|
Forum: Winners' Showcase
06-02-2022, 02:20 PM
|
| |
I would like to nominate this photo
|
|
Forum: Monthly Photo Contests
06-02-2022, 02:19 PM
|
| |
I would like to nominate this photo
|
|
Forum: Pentax SLR Lens Discussion
05-20-2022, 09:43 AM
|
| |
I use the 1.7 with this lens with good results.
|
|
Forum: Lens Clubs
05-17-2022, 05:35 AM
|
| |
Lunar Eclipse. DA* 300mm F4.0 ED with a 1.7 teleconverter, cropped. You can see a little shake in the stars.
|
|
Forum: Monthly Photo Contests
05-08-2022, 06:21 PM
|
| |
The subject is well isolated and composed
|
|
Forum: Pentax SLR Lens Discussion
04-14-2022, 12:17 PM
|
| |
I'll second that. The rear gel filters are cheap and work great. (filters on the rear do not need to phase flat over a large region).
And on a long exposure photograph, who needs auto focus? (the Irix is manual focus).
|
|
Forum: Photographic Industry and Professionals
04-14-2022, 12:05 PM
|
| |
My intent was to sell it all quickly and conveniently. I wrote off my time with them and sold four items on ebay (two Pentax lenses, an old russian lens and a medium format camera kit with 3 lenses). I still have a bunch of lenses to sell. I will put some on PentaxForum Marketplace.
Lenses I have yet to sell:
SMC Pentax-M 50mm F1.4
Takina macro 90mm w/ extender
Takumar 135mm F2.5 Bayonet
SMC Takumar 6x7 200mm F4
SMC Takumar 6x7 400mm F4
SMC Takumar 6x7 600mm F4, 6x7 to K mount adapter
Rear Converter-A 2x-S
Rear Converter-A 2X-L
Large format Camera: Calumet 4x5 rail mount with lens and shutter.
|
|
Forum: Photographic Industry and Professionals
04-14-2022, 08:41 AM
|
| |
I wanted to sell a bunch of gear.
I signed up for an e-meeting with a KEH buyer.
Their web site gave instructions for the meeting, including how to have the light set up to make it easy for the KEH buyer to see the equipment condition.
I spent the time preparing to make this work. I sent a full description of what I was offering, including web addresses to the KEH web site describing each component. I prepared the lighting and had everything ready to show.
In the call, the KEH buyer barely looked at anything I showed. he was too busy fumbling to find the gear in his database.
It was a colossal waste of my time.
|
