Forgot Password
Pentax Camera Forums Home
 

Showing results 1 to 25 of 300 Search:
Forum: Pentax Medium Format 1 Day Ago  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
Nice B&W series Tuco, as usual. I'm shooting in Taiwan with my 67.
Forum: Pentax Medium Format 02-04-2018, 11:08 AM  
Light seals originally on the Pentax 6x7
Posted By desertscape
Replies: 12
Views: 1,121
The light leaks I have had from loading mistakes look different from what you show. When using slide film, the leak manifests itself as a bleached out section of the film, running vertically thru the frame, emanating from the edge. Haven't had this happen with print film, so I can't comment on how that would look.
Forum: Pentax Medium Format 01-26-2018, 02:35 PM  
Reciprocity failure? Provia in low light
Posted By desertscape
Replies: 14
Views: 678
FYI, If you are going to use a gray card, remember that they work especially well with the TTL meter. Typically, the TTL can be faked out by very dark or very light areas in the scene but with the gray card, those errors are lessened greatly. These cards are not as simple to use as you might first expect, so heeding the above advice is warranted.
Forum: Pentax Medium Format 01-25-2018, 01:34 PM  
Reciprocity failure? Provia in low light
Posted By desertscape
Replies: 14
Views: 678
Acros is a negative film while Provia is a slide film. The exposure latitude on neg film is much greater than with slide film. You could have easily been off on your exposure on both types of film but the B&W being more forgiving, didn't show up as being off. The exposure latitude with Provia is not forgiving and will show mistakes. Also, using a handheld meter in a quickly changing scene can be a problem if the light is fading. Sometimes using the TTL meter off the clouds and bracketing works better. Just my guess as to what happened with your Provia.
Forum: Pentax Medium Format 01-24-2018, 12:18 PM  
6x7 removing strap
Posted By desertscape
Replies: 7
Views: 334
There is also a part of Pentax Forums for the 6x7 exclusively. It is called Heavy Pentax-- Heavy Pentax - for 6X7 format users - PentaxForums.com
Just in case you hadn't heard of it.
Forum: Pentax Medium Format 01-22-2018, 02:24 PM  
Pentax 67 400 4.0 ED IF - use with full format 35mm DSLR
Posted By desertscape
Replies: 16
Views: 981
There is a reason why the old 300 is cheap--- No tripod mount, some tertiary spectrum seen wide open, contrast is only fair, very susceptible to shutter vib when used on the 67.
Forum: Pentax Medium Format 01-21-2018, 08:50 PM  
Pentax 67 400 4.0 ED IF - use with full format 35mm DSLR
Posted By desertscape
Replies: 16
Views: 981
James Cormier uses the 400 Takumar with the Pentax 67. I use it for terrestrial work only.
Forum: Pentax Medium Format 01-20-2018, 06:50 PM  
67 vs 645 digital
Posted By desertscape
Replies: 15
Views: 900
Yes, the D and Z show amazing detail. The 67 can show amazing detail as well but only if one is using the best lenses of the lineup, at the best apertures, the finest grain film and a drum scan. To use a Plustek OpticFilm 120 scanner and a 67 slide, the 645D & Z will way outperform the 67. The Plustek 120 + 67 combination has trouble competing against a 20 MP digital camera. A Hasselblad X5 scanner + 67 slide does much better than the cheaper scanners but shows slightly less detail than a drum scan. I recall seeing a 67 shot from a drum scan that was about 36 X 46 Inches and was sharp and I'm sure the D or Z can do that.
Forum: Pentax Medium Format 01-12-2018, 09:05 PM  
Two Big Brutes Fighting Over 6x7 Camera
Posted By desertscape
Replies: 6
Views: 933
If you shoot E6, the best lab for that is AgX in Michigan.Tell us what you shoot and we can tell you what film to use. The 200mm Pentax is exceptional and affordable. The older Takumar is not quite as good.
Forum: Pentax Medium Format 01-12-2018, 01:57 PM  
Pentax 67 400 4.0 ED IF - use with full format 35mm DSLR
Posted By desertscape
Replies: 16
Views: 981
The 400 Takumar and 400 EDIF were both APO but the big difference between the two is the degree of color correction of the uncorrected colors. The use of low dispersion glass in the EDIF gave it the advantage of better correcting the uncorrected colors, while the Takumar would fringe a bit in those colors wide open. The EDIF had much lower spherochromatism than the Takumar; meaning that the difference in color focus by lens zone was much smaller. The 400 Takumar has been used in astro work successfully when stopped down a bit but the EDIF is the one to use if you have the money.
Forum: Pentax Medium Format 01-04-2018, 04:42 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
Thanks, it helps to live in Arizona.
Forum: Pentax Medium Format 01-04-2018, 03:46 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
One of my older Grand Canyon shots in winter-- Pentax 67, Velvia 50, old version.
Forum: Pentax Medium Format 01-04-2018, 03:34 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
The Grand Canyon is not an easy place to shoot. It is so weather dependent that much planning is required to find it at its best. If the Monsoon fails as it did this year, September will be dry with few clouds. The other good season is winter where you get snow on the ground and that makes a good foreground. You got a couple of good shots from a difficult September.
Forum: Pentax SLR Lens Discussion 01-01-2018, 09:15 PM  
the limiteds do they live up to the reputation and why
Posted By desertscape
Replies: 140
Views: 7,571
When field curvature is not eliminated when stopping down, it is not field curvature because as you stop down, the depth of focus increases, masking the curved focal surface. Something else is at play here.
Forum: Pentax Medium Format 12-18-2017, 05:35 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
I kind of like that shot of the intersection. I've seen shots similar to it before but never from straight above.
Forum: Pentax Medium Format 12-17-2017, 01:59 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
Thanks Mike!
Forum: Pentax Medium Format 12-16-2017, 12:42 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
Mike, ANY placement in a magazine these days is quite the accomplishment. Most of my 6x7 work went to calendars but here's one that was published by an Arizona based magazine.
Forum: Pentax SLR Lens Discussion 12-15-2017, 11:16 AM  
front element size - does size matter?
Posted By desertscape
Replies: 68
Views: 2,709
FYI- Spherical is corrected by 3 means; 1. Using an element with the opposite sign as the element that is causing the spherical. If a positive element (plano convex as an example) is causing the marginal rays to focus in front of the focal plane, adding a negative element will mostly compensate for it. 2. Bending the elements toward the diaphragm reduces both spherical and coma. 3. Using aspherical surfaces reduces spherical but in most cases does not completely eliminate it.
Forum: Pentax SLR Lens Discussion 12-10-2017, 01:36 PM  
Macro lenses for landscape?
Posted By desertscape
Replies: 57
Views: 2,252
The major difference between a macro design and a lens designed for infinity work is the correction of spherical aberration. Macros are corrected for spherical at close distances, while non-macro lenses are corrected for spherical at a distance just short of infinity. However, this spherical aberration at infinity can be negated by stopping down the lens to eliminate the zonal spherical aberration. So yes the macro lens can be used successfully for mid distances and infinity.
Forum: Pentax SLR Lens Discussion 12-10-2017, 12:08 PM  
front element size - does size matter?
Posted By desertscape
Replies: 68
Views: 2,709
You are basically saying the same thing I just said above. BTW, most LF lenses are Plasmat designs.

---------- Post added 12-10-2017 at 12:20 PM ----------



The reason why telescopes are so limited by magnification has to do with the fact that they use two optical systems (the telescope's optical design combined with an eyepiece) When an eyepiece is used that magnifies too much and causes unsharpness, it is due to the aberrations from the telescope being magnified. In the photographic world, it would be like using a 10X teleconverter on the back of a long lens.
Forum: Pentax SLR Lens Discussion 12-09-2017, 02:01 PM  
front element size - does size matter?
Posted By desertscape
Replies: 68
Views: 2,709
Optical physics tells us that a larger diameter optic will outperform a smaller one. This is the main reason why larger telescopes will out resolve smaller ones. This is proven; however in photographic optical design, a more important factor is the degree of aberration correction. Aberrations determine performance more than diameter.

Wide lenses (Retrofocus, reverse telephoto, etc) do not fit in the typical "focal length divided by diameter" computation for focal ratio because of the use of a negative lens group in front of the stop. This negative group reduces the size of the entrance pupil. That entrance pupil must be used to figure the focal ratio, not the diameter of the front element. Since the negative group reduces the entrance pupil size, it also reduces the light, therefore the front element must be made larger to compensate.
Forum: Pentax Medium Format 11-14-2017, 02:02 PM  
How do you tote your Pentax 67 or 645?
Posted By desertscape
Replies: 15
Views: 866
I use one of these Tamrac backpacks. They can only be found on the used market now as Tamrac changed their lineup.
Tamrac 777 Expedition Photo Backpack | eBay
Forum: Pentax Medium Format 11-12-2017, 11:40 AM  
Pentax 645 LS 135mm F4 for MACRO with ext-rings ? Quality ?
Posted By desertscape
Replies: 5
Views: 497
Although not exactly what you are asking, I use a 165LS (P 6x7) for macro on a regular basis with tubes. An excellent lens, although you would need an adapter to use on your Z.
Forum: Pentax Medium Format 11-11-2017, 11:49 AM  
considering move to medium format
Posted By desertscape
Replies: 23
Views: 1,313
Your question is similar to what I was asking 30 years ago when I was shooting 35mm film and was questioning the need to shoot 6x7. If you are shooting professionally or plan to in the future, then the extra bit of IQ from the 645D could be a good idea. But if you are shooting for your own enjoyment, the K-1 should do fine. Your talent is way more important than your equipment. Owning a D or Z is not going to suddenly make you a better photographer.
Forum: Pentax Medium Format 11-06-2017, 04:46 PM  
Post your medium format photos!
Posted By desertscape
Replies: 11,473
Views: 1,873,806
Glacial lake, Canada, Pentax 6x7, 55-100 zoom.
Search took 0.01 seconds | Showing results 1 to 25 of 300

 
Forum Jump


All times are GMT -7. The time now is 09:07 AM. | 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