Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-17-2010, 11:40 PM   #1
Veteran Member
Adrian Owerko's Avatar

Join Date: Feb 2008
Location: South Australia
Posts: 435
Rebuilding the 35 MM Format FA* line to the DA* APS-C Format

Rebuilding the 35 MM Format FA* line to the DA* APS-C Format

My roadmap for PENTAX

Attached Images
File Type: pdf Adrian's Pentax Roadmap.pdf (18.1 KB, 720 views)
01-18-2010, 05:38 AM   #2
axl
Inactive Account




Join Date: Mar 2007
Location: Nove Zamky, Slovakia
Photos: Gallery | Albums
Posts: 7,181
I think you forgot FA*400/5.6 which in your map would probably be replaced by DA*300/4
And I think chances of DA*16/2 happeninng are small. I just can't see them making 16mm prime if they have 14/2.8, 15/4 and DA*16-50,
just my 2p

BR
Peter
01-18-2010, 06:49 AM   #3
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
I think there are 2 problems with your map

The first is that you are somewhat in the "trap" of converting to equivelent focal lengths for the ASP-C sensor.

WHile there is a need for a few new lenses, to bring the wide end in line (and pentax has done this with the 12-24 and 10-17 fish-eye, as well as the 16-50 F2.8) you do not address in this, that a lot of shooters actually enjoy the benefits the ASP-C format offers in "reach" or perhaps crop factor. I shoot nature, and want the longest I can afford. For me, unless the new 400F2.8 came with pentax built and supplied matched 1.4x and 2x TCs it still is not long enough.

and where is the 300 F2.8, again witth high quality TCs

The other trap is that many photographers (self included) don't see need to rescale to the equivelent to 35mm idea. While the 50-135 is a fine lens, a 70-200 is much much more useful at F2.8, I accept it is bigger and heavier, and many in the pentax camp still suffer from what I call the M disease (mini disease) carried over from the M-Series film camera days, not everyone wants that.

there really should be 2 lines of lenses, a new digital line, which is mostly complete offering equivelents (including crop factor) to the old film lenses, and a second line with the old (A, F and FA series lenses) remade with the advantage of the new coatings, plus 2 really high quality TCs.
01-18-2010, 09:02 AM   #4
Site Supporter
Site Supporter
GeneV's Avatar

Join Date: Oct 2008
Location: Albuquerque NM
Photos: Albums
Posts: 9,775
I suffer a bit from the "M" disease, which is probably why I own several of the compact limiteds. I also suffer from the lack of certain lenses at the wide end. I really miss the FOV/speed/size of the M 28mm 2.8 ver. 1. I'd like to see the Ltd line rounded out with a compact 18mm/2.8 . Since the 21mm couldn't quite get there and remain pancake small, I realize this lens would need to be a tad bigger.

01-18-2010, 09:10 AM   #5
Veteran Member
pasipasi's Avatar

Join Date: Feb 2008
Location: Oulu
Photos: Gallery
Posts: 533
I think a 18/2.8 even for aps-c would be quite a lot bigger than the M28/2.8. I wanted a small fast wide for digital, so I went for full frame.
01-18-2010, 10:07 AM   #6
Veteran Member
Miserere's Avatar

Join Date: Sep 2007
Location: Boston
Photos: Gallery
Posts: 1,994
DA* 16mm f/2 ain't gonna happen, but I get your point.

While I do suffer from M disease, I am not married to film days FoV. APS-C offers us the chance of a new beginning, and allows us to use many different focal lengths from both formats. Like Lowell, I don't find 50-135mm that useful, and would prefer 70-200mm on APS-C. And wouldn't it be nice if that lens were designe for APS-C? One of the reasons the current Tamron and Sigma 70-200mm f/2.8 lenses are big and heavy is because they are FF. If they were designed for the smaller sensor of APS-C they could be made smaller and lighter.

So again, I agree with Lowell that there should be two lines: One with classic focal lengths, and another with equivalent classic focal lengths.

For example, my walk-around lens is the Tamron 28-75mm f/2.8. If Pentax were to introduce a FF camera and I were to buy it, what walk-around lens would I use...? Answer: I wouldn't have one, because nobody makes a 40-110mm f/2.8 zoom. If I had a FF camera, I'd most likely only use primes with it.

Anyway, this was just to say that despite what the camera companies try to impose on us, we all see the World in different ways, and a lens that is normal to one person, will be long to another, and short to somebody else.

Unfortunately, I don't see Pentax supporting a dual APS-C line of focal lengths. The best we can hope for is there will be a line of small, slow APS-C lenses, and another of large, faster FF lenses (when/if they introduce a FF camera).

.
01-18-2010, 10:33 AM   #7
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
QuoteOriginally posted by Miserere Quote
Like Lowell, I don't find 50-135mm that useful, and would prefer 70-200mm on APS-C. And wouldn't it be nice if that lens were designe for APS-C? One of the reasons the current Tamron and Sigma 70-200mm f/2.8 lenses are big and heavy is because they are FF. If they were designed for the smaller sensor of APS-C they could be made smaller and lighter.
Be careful with this assumption.

Although the rear of the lens can be made a little smaller (at least the glass) the barrel can't change size because the barrel diameter is dictated by the lens mount, and the front element can't be made any smaller because for 200mm F2.8 implies a front element diameter of 72mm. Unless the lens barrel has zero thickness, you need a 77mm filter on the front, which is exactlly what the sigma and tamron have.

If you then consider IF and space in the middle of the barrel for the focusing mechanism etc, there is not a lot to save anywhere.

The laws of physics simply don't care about the image circle difference when you look at tele lenses.

If you want a good example of how little can change in lens design for an ASP-C sensor, the DA300 F4 weight is 1070 grams, where as the SMC 300F4 is 1020 grams.

Both have 77mm filters.

Like I said, an ASP-C sensor, except for some very special lenses, makes no difference AT ALL in weight.
01-18-2010, 11:07 AM   #8
Pentaxian




Join Date: Oct 2006
Location: Chicago suburb, IL, USA
Posts: 1,535
QuoteOriginally posted by Lowell Goudge Quote
Be careful with this assumption.

Although the rear of the lens can be made a little smaller (at least the glass) the barrel can't change size because the barrel diameter is dictated by the lens mount, and the front element can't be made any smaller because for 200mm F2.8 implies a front element diameter of 72mm. Unless the lens barrel has zero thickness, you need a 77mm filter on the front, which is exactlly what the sigma and tamron have.

If you then consider IF and space in the middle of the barrel for the focusing mechanism etc, there is not a lot to save anywhere.

The laws of physics simply don't care about the image circle difference when you look at tele lenses.

If you want a good example of how little can change in lens design for an ASP-C sensor, the DA300 F4 weight is 1070 grams, where as the SMC 300F4 is 1020 grams.

Both have 77mm filters.

Like I said, an ASP-C sensor, except for some very special lenses, makes no difference AT ALL in weight.
Although I disagree with both concerning the 50-135 -- IMO, this is a great alternative for the 70-200/2.8 for events and candids offering the traditional FOV in a much lighter and less intimidating package. A 70-200/2.8 and external flash is just too much for me to drag up to my eye a couple of hundred times during a day. . .

That being said, I agree with Lowell about smaller formats do not lead to smaller lenses. Probably the best examples can be shown looking at the Oly 4/3 lenses, with the 300/2.8 a sterling example. It's 3.3 kg, while the largest, heaviest alternative in the Pentax line for this class lens is the FA*300/2.8 at 2.9kg. Granted, the Oly is WR, but that shouldn't add almost half a kilo. . . and we're comparing 35mm vs 4/3 here.

Scott

01-20-2010, 06:29 AM   #9
Forum Member
eljaco's Avatar

Join Date: Aug 2009
Location: Courbevoie
Posts: 72
QuoteOriginally posted by Miserere Quote
For example, my walk-around lens is the Tamron 28-75mm f/2.8. If Pentax were to introduce a FF camera and I were to buy it, what walk-around lens would I use...? Answer: I wouldn't have one, because nobody makes a 40-110mm f/2.8 zoom. If I had a FF camera, I'd most likely only use primes with it.
.
What about a 35-105 F3.5? Or maybe a K45-125 F4?

Anyway, I agree - Pentax should not necessarily try to adapt FF focale range to APS, especially since many users now, young ones like me, with no or little film experience, have no reference to FF, so they do not care about any film/FF conversion...

They should release what makes sense as of today to fill the gaps. For example:
- DA28 (to sit btw DA21 & DA35)
- DA135-400 (I'm not a long range shooter though)
- DA10
- DA400
01-20-2010, 06:48 AM   #10
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
QuoteOriginally posted by eljaco Quote
What about a 35-105 F3.5? Or maybe a K45-125 F4?
this adds another dimension, these would be purely consumer lenses, since they are much slower, and overlapping the 16050 and 50-135 lenses. The thought of both a full consumer line and a more heavily populated "popsumer" line is an intersting thought for many shooters, especially those new to photography
QuoteQuote:
Anyway, I agree - Pentax should not necessarily try to adapt FF focale range to APS, especially since many users now, young ones like me, with no or little film experience, have no reference to FF, so they do not care about any film/FF conversion...

They should release what makes sense as of today to fill the gaps. For example:
- DA28 (to sit btw DA21 & DA35)
- DA135-400 (I'm not a long range shooter though)
- DA10
- DA400
agreed on your list, but at what aperture?

the answer I believe should be DA135-400 F5.6 and DA400 F4.

a 135-400 F5.6 would be a direct competitor for the longer sigma zooms, the 400 F4 which would probably be a 112 mm front element would be of interest to me, and I am sure a lot of others as well. But again, the issue would be 400F4 or 300 F2.8 plus a pentax designed matching 1.4x and 2X TC. Personally for me, the latter is a whole lot more interesting.
01-20-2010, 07:06 AM   #11
Senior Member
paulelescoces's Avatar

Join Date: Sep 2009
Location: Singapore
Photos: Gallery
Posts: 241
I think all that you have would be nice, calling it a roadmap also suggests the understanding that its not all for tomorrow.

What I would like to see are DA* versions of the FA Limiteds (31, 43, 77). shame that the greatest pentax lenses are WR and SDM less (although some population would prefer no SDM).
01-20-2010, 09:06 AM   #12
Veteran Member
Miserere's Avatar

Join Date: Sep 2007
Location: Boston
Photos: Gallery
Posts: 1,994
QuoteOriginally posted by eljaco:

What about a 35-105 F3.5? Or maybe a K45-125 F4?

QuoteOriginally posted by Lowell Goudge Quote
this adds another dimension, these would be purely consumer lenses, since they are much slower, and overlapping the 16050 and 50-135 lenses.
Not necessarily, Lowell. As you know, Canon has a very successful, high quality f/4 zoom line, which many people prefer, even those who could afford the f/2.8 versions. In fact, a very common complaint amongst Nikon users is that Nikon refuses to release an f/4 zoom line up. Going even further, Pentax has (or had) a history of producing excellent f/4 zooms in the K, M and A days.

If (and that's a big if) I bought a FF DSLR, I'd love a 35-105mm f/3.5, especially if it were as good as Pentax's version, which is compact, and provides great IQ at all focal lengths and apertures. The Pentax 45-125mm f/4 is also a very nice lens (owned one for a while), and if they widened it a bit to 40mm I'd also be interested in one for a potential FF camera. Obviously, they would build only one of these lenses, not both.

.
01-20-2010, 09:26 AM   #13
Veteran Member
Miserere's Avatar

Join Date: Sep 2007
Location: Boston
Photos: Gallery
Posts: 1,994
QuoteOriginally posted by Lowell Goudge Quote
Be careful with this assumption.

Although the rear of the lens can be made a little smaller (at least the glass) the barrel can't change size because the barrel diameter is dictated by the lens mount, and the front element can't be made any smaller because for 200mm F2.8 implies a front element diameter of 72mm. Unless the lens barrel has zero thickness, you need a 77mm filter on the front, which is exactlly what the sigma and tamron have.
Yes, true, not that much mass can be shaved off, although internal elements can be made smaller....but maybe not by much. And you're quite right that the barrel to the rear has to stay at a similar size because of the mount is the same. That said, Pentax do know how to make compact lenses, which makes it difficult for them to improve in this area. Have you ever held an FA* 300mm f/4.5? The theoretical width for the front element is 66.8mm; the filter size for the lens is 67mm. And if you look into the lens, the front part of the barrel is extremely thin. In fact, the lens is 73mm at its widest. Like I said, you'd be hard pressed to improve on this. Sigma, on the other hand, is not known for small lenses (although to be fair, the Pentax FA* 80-200mm f/2.8 also has a 77mm filter).


QuoteQuote:
If you want a good example of how little can change in lens design for an ASP-C sensor, the DA300 F4 weight is 1070 grams, where as the SMC 300F4 is 1020 grams.

Both have 77mm filters.
The thing is, the DA* 300 seems to work pretty well on Full Frame, so I don't think it was designed to really be APS-C only.

.
01-20-2010, 10:14 AM   #14
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
QuoteOriginally posted by Miserere Quote
Yes, true, not that much mass can be shaved off, although internal elements can be made smaller....but maybe not by much.
only the rear element because of the smaller image circle, but not any of the ones in front of the aperture.
QuoteQuote:
And you're quite right that the barrel to the rear has to stay at a similar size because of the mount is the same. That said, Pentax do know how to make compact lenses, which makes it difficult for them to improve in this area.
also true
QuoteQuote:
Have you ever held an FA* 300mm f/4.5? The theoretical width for the front element is 66.8mm; the filter size for the lens is 67mm. And if you look into the lens, the front part of the barrel is extremely thin. In fact, the lens is 73mm at its widest. Like I said, you'd be hard pressed to improve on this. Sigma, on the other hand, is not known for small lenses (although to be fair, the Pentax FA* 80-200mm f/2.8 also has a 77mm filter).
note however that pentax is also probably using the tolorances allowed on either focal length, making the lens a few mm short, or on aperture itself, to take advantage of the packaging, to get the lenses smaller than a more conservative design.

This also is a function of assembly process, and some of these lenses may be a little different to disassemble as a result



QuoteQuote:
The thing is, the DA* 300 seems to work pretty well on Full Frame, so I don't think it was designed to really be APS-C only.

.
I think it is just a function of a long tele in general, image circle is not really a restriction like it is on a wide angle.
01-20-2010, 11:04 AM   #15
Forum Member
eljaco's Avatar

Join Date: Aug 2009
Location: Courbevoie
Posts: 72
QuoteOriginally posted by Lowell Goudge Quote
this adds another dimension, these would be purely consumer lenses, since they are much slower, and overlapping the 16-50 and 50-135 lenses. The thought of both a full consumer line and a more heavily populated "popsumer" line is an intersting thought for many shooters, especially those new to photography
Well, the 35-105 (as an equivalent to Miserere's 28-75 ) is half a stop slower, so not a big deal if it performs well at 3.5. But anyway, if a FF is released, I don't see anyone releasing such a lens nowadays. Not wide enough for most people, and not long enough on the other hand...

QuoteOriginally posted by Lowell Goudge Quote
agreed on your list, but at what aperture?
the answer I believe should be DA135-400 F5.6 and DA400 F4.
Hard to say, because this performance vs price vs portability.
I guess the following would be achievable without being too pricey:
DA28 f2
DA10 F4 (not a fish-eye btw...)
DA400 F5.6 - F4 would make it big... and expensive I think (and the FA400 f5.6 already exists...)
DA135-400 F4~F5.6 - similar lenses exist for Canon/Sony/Nikon... in FF, though.
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!
aps-c, da*, fa*, format, k-mount, line, mm, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
RAW format to use for new K-x? p-bags Pentax DSLR Discussion 15 04-09-2010 01:44 PM
RAW Format pakuchn Troubleshooting and Beginner Help 5 01-23-2010 12:40 PM
Square Format karaoke Pentax DSLR Discussion 14 04-22-2008 01:53 PM
The OpenEXR format bc_the_path Digital Processing, Software, and Printing 0 11-16-2007 03:04 AM



All times are GMT -7. The time now is 02:41 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