Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-30-2015, 03:25 AM   #31
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 342
Considering Hasselblad has not one but two WA lenses designed specifically for smaller sensors, I don't see why Pentax should feel ashamed in making a lens specifically for the 33x44 format. Well, seeing as technically there already is a wide lens for the 645, Pentax probably won't be too thrilled at the idea of replacing a new lens like that very soon, but I can think of a compromise - make a WA tilt-shift of around 24mm made for use on 33x44 format, while also allowing it to be used on full-frame 645 film or future sensor unshifted.

Pentax has killer potential at their door if they make a TS lens that's anywhere near as good as the Canon 24mm TS-E. I keep saying this, but if Pentax make a lens like this and also a roughly 100mm f/2 portrait lens with leaf shutter, 645Z's are going to be back-ordered for years.

05-30-2015, 09:26 AM   #32
Junior Member




Join Date: Apr 2015
Posts: 47
Totally agree. A TS-E type lens would be amazing. At present I am having to adapt my 24mm TS-E for the A7R because the dynamic range of my 5D III stinks for urbanscapes at night.
05-31-2015, 10:15 AM   #33
Site Supporter




Join Date: Oct 2009
Location: Living in Vancouver, BC, born in Melbourne Australia
Photos: Albums
Posts: 156
QuoteOriginally posted by batmobile Quote
For the wide prime, considering the existence of the 28-45, 22mm would be about right IMO.
With shift capabilities.
I've just started with my Z, and if I had two perspective correcting lenses in the 20 and 35 range, I don't think my Canon system would see much use...
05-31-2015, 10:22 AM   #34
Junior Member




Join Date: Apr 2015
Posts: 47
Agreed.

17mm and 24mm from canon is nice (I only have the latter), but 18-20mm and 35mm equivalent would be much better. Within the Canon EF system the gap between the 24mm and 45mm TS-E lenses is pretty large. A 35mm equivalent would get a LOT of use, including for stitching.

QuoteOriginally posted by lats Quote
With shift capabilities.
I've just started with my Z, and if I had two perspective correcting lenses in the 20 and 35 range, I don't think my Canon system would see much use...


06-01-2015, 03:41 AM   #35
Pentaxian




Join Date: Apr 2013
Location: Brisbane, Australia
Posts: 633
Original Poster
I think that certain focal lengths lend themselves more to either tilt or shift.

For example on the 645z, I would take a 35mm (28mm) tilt lens and a 24mm (19mm) shift lens.

You need the depth of field on the 35 and you need the shift on the 24.

Just my preference, why crowd the lens with too many things to go wrong.
06-01-2015, 04:16 AM   #36
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 342
QuoteOriginally posted by 2351HD Quote
I think that certain focal lengths lend themselves more to either tilt or shift.

For example on the 645z, I would take a 35mm (28mm) tilt lens and a 24mm (19mm) shift lens.

You need the depth of field on the 35 and you need the shift on the 24.

Just my preference, why crowd the lens with too many things to go wrong.
May as well make the most use of resources and design a lens that does both really well, since it's going to end up being a rather hefty and high-priced optic anyway. Even if it had a 5.6 aperture, weighed over 1 kilo and would require it's own tripod mount, I think most people would be happy. In fact, I really hope that Pentax make a tripod-mountable tilt-shift so that you don't have to correct for parallax when doing in-lens panos.

One thing I want to point out is that more than tilt, shifting requires the effective focal length and image circle to be significantly larger than the intended format, for instance the EF 24mm TS-E is actually a 17mm lens, while the 17mm TS-E is actually 11mm, if you take into account the expanded field of view from maximum shift. From a technical standpoint, it would be easier to design a tilt-only super wide, as shifting is a pricey commodity.

Every shift lens can effectively be thought of as two lenses; the focal length as you get from one shot, and the effective FL as you can get by stitching shots in-lens, so it would be a very bad idea to strip any such lens of this feature.
06-04-2015, 10:47 PM   #37
Senior Member




Join Date: Mar 2012
Posts: 158
Pentax better get going. Phase One returned to the game with their XF and two apparently superlative fixed focal lenses, a 35mm and a 120mm macro, both apparently ready for a 100MP sensor.

I was never sure whether the apparent overdesign of the 25 was such a bad thing as the later design eliminated the corners in favor of the superior center. The large design may still work as the basis for the shift lens we all seem to need....

I respect the 28-45mm fans for its sharpness and lack of color fringing, but not for the barrel distortion at 28mm - the 25mm is almost distortion free! Just went out with the zoom today and occasionally thought about the 25 prime, but admittedly, the zoom is very versatile.
06-05-2015, 12:15 AM   #38
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 342
Based on what I've heard at GetDPI from a reputable Phase dealer, the 120mm is a rehoused Phase/Mamiya 120mm but with a leaf shutter added, rather than an all-new optical design. The 35mm however is a new lens.

Personally I'm just not feeling the XF. Not sure what I was expecting from a new-gen Phase camera, but it doesn't give me any desire to own one, no matter how much I look at or read about it. At $40k starting and hefty prices for those lenses, Pentax still don't have to worry about much, photographers looking for the last 5% of image quality probably aren't looking at Pentax anyway.

QuoteOriginally posted by Lacunapratum Quote
I respect the 28-45mm fans for its sharpness and lack of color fringing, but not for the barrel distortion at 28mm - the 25mm is almost distortion free! Just went out with the zoom today and occasionally thought about the 25 prime, but admittedly, the zoom is very versatile.
Depending on the subjects you shoot, distortion isn't a problem, and if it is, reducing it doesn't significantly impact sharpness. If you wanted to go out and specifically take photos of something that consisted of parallel lines, then of course the 25mm could be better choice.


Last edited by Kolor-Pikker; 06-05-2015 at 12:37 AM.
06-05-2015, 02:32 AM   #39
New Member
Apotessar's Avatar

Join Date: Jun 2015
Posts: 19
QuoteOriginally posted by Kolor-Pikker Quote
May as well make the most use of resources and design a lens that does both really well, since it's going to end up being a rather hefty and high-priced optic anyway. Even if it had a 5.6 aperture, weighed over 1 kilo and would require it's own tripod mount, I think most people would be happy. In fact, I really hope that Pentax make a tripod-mountable tilt-shift so that you don't have to correct for parallax when doing in-lens panos.

One thing I want to point out is that more than tilt, shifting requires the effective focal length and image circle to be significantly larger than the intended format, for instance the EF 24mm TS-E is actually a 17mm lens, while the 17mm TS-E is actually 11mm, if you take into account the expanded field of view from maximum shift. From a technical standpoint, it would be easier to design a tilt-only super wide, as shifting is a pricey commodity.

Every shift lens can effectively be thought of as two lenses; the focal length as you get from one shot, and the effective FL as you can get by stitching shots in-lens, so it would be a very bad idea to strip any such lens of this feature.
The Canon lenses are even wider. I use them on a 48*36 mm Chip with movements. These two lenses are incredible. But Canon seems to be the only company at the moment who is able to produce this kind of extreme lenses. As i heard it is some kind of pressed glass. The Images shows a 2 x 36*48 mm shot with the Canon TS-E 17 mm. The view angle is about 150.




Greetings from Switzerland
a proud new 645Z owner ;-)
06-05-2015, 05:19 AM - 1 Like   #40
Junior Member




Join Date: Apr 2015
Posts: 47
Totally agree re barrel distortion of the 28-45 lens, but I shoot natural scenes and have no images that do not correct perfectly, when needed.. For urbanscapes, it may prove challenging and with the 25mm's curvature that could work in your favour if inside the city, rather than looking at it from afar, if you follow me.

I think Pentax is four lenses away from being in a commanding position (for scenic shooters):

Using real, rather than converted focal lengths:

20-22mm prime.
28mm filt/shift
45-85 replacement
80-160 replacement.

Anything they add after this will be a bonus. I'd like to see:

18mm prime
45mm tilt/shift

and then I'd be struggling. Perhaps a slow but razor sharp 150-300mm zoom would be worthwhile, but ...

There is no doubt the 28-45 DA and 75mm FA will handle more resolution, along with the 90mm Macro, so I think we can expect to see a mild refresh of the 645Z in a few years with circa 65-80MP. The body is close to perfect, if you ask me.

For portrait shooters I can see the urgent need for some really characterful and fast lenses between 60 and 120mm
06-05-2015, 01:14 PM   #41
Site Supporter




Join Date: Oct 2009
Location: Living in Vancouver, BC, born in Melbourne Australia
Photos: Albums
Posts: 156
Been doing a little more thinking on this.

Yeah, I think (personally) that a 645 30mm (26mm in 135format) range would be the go to lens for an AP on this system.
28, is just that little bit too tight for the majority of work.

Then something around 645 20-22 (17-19mm in 135format) would be wonderful.
I don't find myself using the Canon 17 all that often due to circles becoming ovals as they near the edge of the frame, but every now and then....I need it and love it.

If they took that original 25mm design and were able to incorporate 10-15mms of movement on it, I'd be a happy man!


QuoteOriginally posted by 2351HD Quote
I think that certain focal lengths lend themselves more to either tilt or shift.

For example on the 645z, I would take a 35mm (28mm) tilt lens and a 24mm (19mm) shift lens.

You need the depth of field on the 35 and you need the shift on the 24.

Just my preference, why crowd the lens with too many things to go wrong.
06-05-2015, 02:30 PM   #42
Loyal Site Supporter
Loyal Site Supporter
unkipunki's Avatar

Join Date: Dec 2012
Location: South Lochaweside, Argyll
Photos: Gallery
Posts: 540
- TBH I am so impressed with recent lenses (55mm , 28-45mm and 90mm macro) i find it hard to retro invest. I own the 645 A 200, it is nice but no show stopper on this sensor. I am on tenterhooks for the bridging zooms 45-85? 85-160?. The primes to follow will be incredibly good I think. But as the newest zoom seems to me to out resolve the sensor I'm happy to see the zooms come first. It would be good to see primes drop in thereafter. Beyond that more exotic TS lenses will also be welcome.
06-07-2015, 01:17 PM   #43
Pentaxian




Join Date: Apr 2013
Location: Brisbane, Australia
Posts: 633
Original Poster
I agree. I just can't find myself liking the current FA 80-160 after using the 90 macro.

I can't wait to clean out the bag and shelves and get the new tele zoom.
08-02-2015, 11:19 AM   #44
Loyal Site Supporter
Loyal Site Supporter
unkipunki's Avatar

Join Date: Dec 2012
Location: South Lochaweside, Argyll
Photos: Gallery
Posts: 540
Still no hint of timescale on new 645 lenses. I may have to 'invest' in the existing 80-160 but the way this summer's going I am very wary of non AW lenses. Really hope there's some news soon
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
645d, 645z, camera, equivalent, ff, format, lens, light, medium format, terms
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rumours when the new zooms come?? Shanti Pentax News and Rumors 91 01-03-2015 09:07 AM
Super Zooms vs normal zooms robert52 Pentax SLR Lens Discussion 9 10-12-2014 07:29 PM
Zooming with your feet, will new zooms end that? VoiceOfReason Pentax SLR Lens Discussion 53 02-10-2014 06:17 PM
WR zooms vs IQ zooms being considered ChooseAName Pentax SLR Lens Discussion 12 10-22-2012 03:17 PM
Cheap old zooms or cheap new zooms better? okto Pentax SLR Lens Discussion 3 11-21-2006 02:49 PM



All times are GMT -7. The time now is 01:29 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