Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-03-2013, 09:06 AM   #1
Site Supporter
jcdoss's Avatar

Join Date: Nov 2012
Location: Kansas City, MO
Photos: Gallery | Albums
Posts: 1,914
400/5.6, M vs A

Both are available @ KEH, and the A version, as usual, is somewhat pricier. The review page states these two have different optical formulas, but I was unable to find a direct comparison. Any opinions? The A setting isn't important to me.

08-03-2013, 11:02 AM - 1 Like   #2
Veteran Member
Schmidlapper's Avatar

Join Date: Dec 2008
Location: Pennsylvania
Photos: Gallery
Posts: 532
They weight the same and both have built in hoods and tripod collars, same largest aperture, and you don't care about the A setting, so it comes down to two issues; the first is optical qualities. The A according to the database on here rates the A slightly higher especially for bokeh and aberration, which would mean the changes made from the M to A version addressed those short comings without making something else worse. The second is price, which is the real major difference as it almost always is. In the used market you are not paying for manufacturing costs differences, instead you are paying for desirability differences, be it for rarity or perceived value. So my point is the market has assigned a higher perceived value to the A's technical merits, so it comes down to your comfort level spending the difference for the A over the M. I have an A version and it takes dedication to use it with a digital SLR as they come from two different focusing eras. It is sharper and longer than my DA55-300, but the auto focus and lighter weight of the DA are often desirable enough to make me accept those drawbacks. I wish you well on your decision and in summery, Get the A.
08-03-2013, 11:11 AM - 1 Like   #3
Loyal Site Supporter
baro-nite's Avatar

Join Date: Aug 2011
Location: North Carolina, USA
Photos: Gallery | Albums
Posts: 4,364
Some other differences: minimum focus distance, 280cm for the A vs. 500cm for the M. A version is compatible with the Pentax-A Rear Converter 1.4x-L and 2x-L; M version is not.
08-03-2013, 11:27 AM - 1 Like   #4
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,845
I've got the A, manual focus is enough to think about without having to keep track of exposure. I know you said it's not important to you, but, others with the M-400 have said they wish they had the A. Why complicate life?







This last one taken from a Km away, I took five shots and one was good, but one was all I needed. It's different working with a lens this long.

More images here....

08-03-2013, 11:54 AM - 1 Like   #5
Veteran Member
Schmidlapper's Avatar

Join Date: Dec 2008
Location: Pennsylvania
Photos: Gallery
Posts: 532
QuoteOriginally posted by normhead Quote
I've got the A,
Normhead seems to have one of the best version of this lens I have seen, some might say his is a little magical. Mine on the other hand takes great pleasure in finding my inadequacies.
08-03-2013, 12:46 PM - 1 Like   #6
Veteran Member
demp10's Avatar

Join Date: Jun 2011
Location: Atlanta
Photos: Albums
Posts: 602
They have different optical formulas. The K and M look identical and have 5 elements in 5 groups. The A has 7 elements in 6 groups.

I have the M version and it is OK. It works much better if you stop it to F8 or F11 and nail focus with Live view, but then you have to use the green button all the time and for wildlife this get old very fast. Also I prefer to shoot in TAv mode where I set the proper speed and f-stop and let the ISO float; with the M version this is not possible.

A while after I got the M 400/5.6 I found a very nice copy of the Tokina AT-X 150 (150mm - 500mm at constant F5.6) with A contacts. It is much heavier (requires monopod or tripod) but the image quality is much better, it has longer reach (500 mm), and it is a lot more convenient with the A setting. Since then, the M 400 had very little use.
08-03-2013, 12:53 PM - 1 Like   #7
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,845
QuoteOriginally posted by demp10 Quote
They have different optical formulas. The K and M look identical and have 5 elements in 5 groups. The A has 7 elements in 6 groups.

I have the M version and it is OK. It works much better if you stop it to F8 or F11 and nail focus with Live view, but then you have to use the green button all the time and for wildlife this get old very fast. Also I prefer to shoot in TAv mode where I set the proper speed and f-stop and let the ISO float; with the M version this is not possible.

A while after I got the M 400/5.6 I found a very nice copy of the Tokina AT-X 150 (150mm - 500mm at constant F5.6) with A contacts. It is much heavier (requires monopod or tripod) but the image quality is much better, it has longer reach (500 mm), and it is a lot more convenient with the A setting. Since then, the M 400 had very little use.
I quite often shoot wide open with the A, it must be a better lens.

A 400 ƒ5.6 taken @ f5.6



Some like this one taken with the Pentax 1.7 TC extend the range to 680mm which would be an equivalent of about 1000mm FF.



and this one, shot "wide open" @ ƒ 9.5 (with the TC).



Incidently, I can't use this lens without a tripod, though I've foolishly wasted my time many times trying. I've taken to only using it with a sturdy tripod and a 2 sec delay where ever possible. Results with a lightweight portable tripod and hand held have been dismal. (Although my medium weight $130 Manfrotto seems to do just fine.)

Last edited by normhead; 08-03-2013 at 01:14 PM.
08-03-2013, 01:06 PM   #8
Site Supporter
jcdoss's Avatar

Join Date: Nov 2012
Location: Kansas City, MO
Photos: Gallery | Albums
Posts: 1,914
Original Poster
Excellent... presuming both are still available when I finally get around to buying, I'll definitely shoot for the A.

08-03-2013, 03:41 PM   #9
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,861
Between a lot of M and A long telephotos, Pentax started changing formulas for less CA and fringing. If the A version has a different formula, that's probably why. It is less of an issue if you stop down, but you don't want to do a lot of stopping down at 400mm.
08-03-2013, 05:15 PM   #10
Site Supporter
gofour3's Avatar

Join Date: Oct 2008
Location: Vancouver, Canada
Posts: 5,339
QuoteOriginally posted by demp10 Quote
They have different optical formulas. The K and M look identical and have 5 elements in 5 groups. The A has 7 elements in 6 groups.
The K400/5.6 is different from the M400/5.6 as it has a manual diaphragm, so you need to use stop-down metering. If you’re going that route (manual diaphragm) then the K500/4.5 is a faster/better all around lens.

Phil.
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!
k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax A 400/5.6 Schmidlapper Lens Sample Photo Archive 5 09-07-2016 01:46 PM
Wanted - Acquired: Pentax-A 400 f/5.6 baro-nite Sold Items 7 12-29-2011 06:56 AM
Nature Collared Dove... K-5 + M-400/5.6 igor Post Your Photos! 10 11-26-2011 12:51 PM
A few more from the M 400/5.6 8540tomg Post Your Photos! 6 07-01-2009 07:35 PM



All times are GMT -7. The time now is 12:02 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