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A long lens suggestion to try out.

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brandrx

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Hi folks,

I don't recommend that anyone go out and buy this stuff just to try it out. However, for what it's worth, the Pentax-A 400mm f5.6 has been a neglected lens around here. It's a pretty good lens and if you already own one then I suggest you give it a try, especially at f8 aperture. You can even use it doing carch-in-focusing against wildlife.

Another for what it's worth: I just tested mine with the Pentax-F 1.7X AF Adapter in good light. It autofocused fine and the images were not bad at all.

Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
My mountain top from about eight miles (I think). Distance is just my guesstimate.

Pentax K-5 + Pentax-A 400mm f5.6 at f8, 1/500s, ISO200, Catch-in-Focusing, handheld.



A crop from the previous image.



Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
My other mountain top. Guesstimate is two or more miles away.

Pentax K-5 + Pentax-A 400mm f5.6 at f8, 1/500s, ISO160, Catch-in-Focusing, handheld.



A crop from previous image.



Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
Looks pretty good Ron.

The optics are different to the M-400/5.6 which I have, but I have been impressed with that too.

Cheers,

Rod

--
All I want is a digital back for my trusty K1000 . . .
 
BobORama said:
How is the CA? I'm curious because its something I can't PP away for the particular application I have in mind. I looks like you have achieved some good results with it.
Click to expand...
Hi Bob,

The truth is, I don't really know. I bought this lens many years ago when I set out to buy all of the Pentax-A lenses for my collection (which I fell short of accomplishment). After I bought the Pentax-A*300/4 and the Pentax-F 1.7X AF Adapter, which combo I used almost all the time, I kind of neglected the Pentax-A 400mm f5.6 lens. I seem to remember some discussions going on (about five or six years ago) comparing the CA of the Pentax-A 400mm f5.6, SMC K400/5.6, SMC M400/5.6, and the M42 Super-Multi-Coated TAKUMAR 400/5.6 lenses. If I remember correctly the Pentax-A 400/5.6 came out on top.

If I can find the time, I will try to take some images that will show the CA (or lack of CA) of the lens when used with the K-5.

What is the particular application you have in mind for a lens like this?

Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
A long term timelapse opportunity where I don't want to park $2300 of ( rented ) glass on the roof. ;-) CA is an issue in that the in camera CA reduction will not work with the A series, as it does with the DA series. I did not see anything to terrible in your posted images, but I don't know what sort of PP you applied.

I would go cheap with the kit 55-300 or whatever, but the CA is egregious on the long end - though some of that would be mitigated by the in-camera processing. The 400 5.6 comes up now and then for sale, so was thinking it could do the job and has a mount.

The particular project would be about 16,000 shots over a few weeks, and there is just no practical way to apply PP correction to that many shots, and they would be JPG's which limits the type / amount of PP you can do. Shooting 16,000 RAW is not yet an option. Perhaps 5 years out.

-- Bob
http://blog.trafficshaper.com
http://www.vimeo.com/boborama/videos
http://www.youtube.com/profile_videos?user=bob0rama
http://public.fotki.com/boborama/
 
Bob,

I searched my backup hard drive and found very little concerning the Pentax-A 400mm f5.6 lens. I just didn't use the lens very much.

Images (except the last one) are unprocessed jpgs. Image #1 through #4 were taken with the K10D. Image #5 was taken with the *istDS. I can upload any of these full size jpgs if you want. Let me know which one/ones.

Image #1



Image #2



Image #3



Image #4



Image #5



Image #6 - Cropped and post-processed from Image #4



Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
Nice capture Greg. Thanks for showing.

Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
Ron, these are much more impressive than your mountain shots. Those seemed to lack contrast and detail. Is it possible that the lens doesn't pair with the 1.7x very well?
 
Mark Ransom said:
Ron, these are much more impressive than your mountain shots. Those seemed to lack contrast and detail. Is it possible that the lens doesn't pair with the 1.7x very well?
Click to expand...
Hi Mark,

The mountain shots were taken with just the 400/5.6 lens. It was a bit hazy as it has been for a couple of weeks now. I also shot them handheld.

I think I jumped the gun about the 1.7X AF Adapter. I can get autofocus with the 1.7X but I now don't think the images will be that good.

Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
I bought an A400mm f5.6 lens two years ago when Ron pointed out that Adorama had it at a good price. (Thank you, Ron!) For my use, I think it's a nice lens. Here are two K10D (unremarkable) hawk pictures that show some lateral chromatic aberration visible against the sky:

1/750 sec, f9.5, ISO 280, camera jpeg without pp



100% crop, center:



100% crop, right side:



100% crop, top:



This picture shows about the worst, I think:
1/750 sec, f8, ISO 280, camera jpeg without pp



100% crop, lower right corner:



But as Greg's and Ron's pictures show, it's usually not a problem. I have a few other pictures with this lens at http://manekidesign.com/rob/photos/wildlife-a400lens/index.htm , but they are not really up to the standards for this forum.

I hope this helps.

Best regards,
Rob Higley

--

 
Hi Rob
That little amount of CA looks pretty good to me.

I think that with an overcast sky it would highlight it more though, that's my experience anyway. A nice blue sky makes it less noticeable.

Cheers,

Rod

--
All I want is a digital back for my trusty K1000 . . .
 
Rod Herdman said:
I think that with an overcast sky it would highlight it more though, that's my experience anyway. A nice blue sky makes it less noticeable.
Click to expand...
Hi Rod -

You're right and that reminds me of one photo I took just after I got the lens - a bit of out of focus chicken wire against the snow looks worse than any others I have with this lens.

K10D, f5.6, 1/350 sec, ISO 800. In keeping with the spirit of no pp, only the curves were adjusted in PPL - it was underexposed:



ear, 100% crop:



corner, 100% crop:



My apologies for nibbling at this thread with bad examples of a lens. What matters, of course, is what nice things one can do with a lens.

Best regards,
Rob Higley

--

 
BobORama said:
I would go cheap with the kit 55-300 or whatever, but the CA is egregious on the long end - though some of that would be mitigated by the in-camera processing. The 400 5.6 comes up now and then for sale, so was thinking it could do the job and has a mount.
Click to expand...
Since 300mm will suit, you should also consider the A*300mm f/4. IQ is a significant step up from the 55-300, and it has lower CA. From what I see here, I believe the A*300 is also a better performer than the A 400 f/5.6.
--
Dan
 
audiobomber said:
BobORama said:
I would go cheap with the kit 55-300 or whatever, but the CA is egregious on the long end - though some of that would be mitigated by the in-camera processing. The 400 5.6 comes up now and then for sale, so was thinking it could do the job and has a mount.
Click to expand...
Since 300mm will suit, you should also consider the A*300mm f/4. IQ is a significant step up from the 55-300, and it has lower CA. From what I see here, I believe the A*300 is also a better performer than the A 400 f/5.6.
Click to expand...
If you go with the Pentax-A*300/4 then I suggest a long lens support.
Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
Rob Higley said:
My apologies for nibbling at this thread with bad examples of a lens. What matters, of course, is what nice things one can do with a lens.
Click to expand...
No need to apoligize Rob. It is good to know the good as well as the bad of a lens. It helps a person to decide if it will suit their purposes or not.

Cheers.

Ron

--
Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'

'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx
 
audiobomber said:
BobORama said:
I would go cheap with the kit 55-300 or whatever, but the CA is egregious on the long end - though some of that would be mitigated by the in-camera processing. The 400 5.6 comes up now and then for sale, so was thinking it could do the job and has a mount.
Click to expand...
Since 300mm will suit, you should also consider the A*300mm f/4. IQ is a significant step up from the 55-300, and it has lower CA. From what I see here, I believe the A*300 is also a better performer than the A 400 f/5.6.
Click to expand...
One of the local art profs has the A* 300mm 1:4 which was crusty and filthy, but I gave it a test drive yesterday. I was thinking 400mm would be needed, but I keep forgetting about the crop factor of the K-5. Baking that in you have a 4.5 degree wide FOV which will be fine.

The IQ of the A* 300 was very impressive, very bright, and with optical defects I can easily fix in post. CA and vignetting wide open were not really noticeable. I guess in part due to the K-5 using the central region of the lens.

This morning I saw one on e-bay and bought it. :-)

-- Bob
http://blog.trafficshaper.com
http://www.vimeo.com/boborama/videos
http://www.youtube.com/profile_videos?user=bob0rama
http://public.fotki.com/boborama/
 
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