Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-23-2016, 07:58 AM   #31
Veteran Member
Barry Pearson's Avatar

Join Date: Jul 2013
Location: Stockport
Posts: 870
QuoteOriginally posted by monochrome Quote
A test is not a test unless the aperture is f/2.8. Otherwise the plane of focus is far to deep to actually test the AF.
I know that was sarcastic, but I've given this some thought.

I've seen a request here for something like a long burst of a fast moving object coming towards the camera, to show whether or not all the frames are in focus. (The assertion being that only a few will be).

A long burst (say 12 or more frames) on the K-1 takes about 3 seconds or so. A fast moving object (for example, a racing car or bike) can go a long way in that time.

If the last frame, where the object is probably fairly close and fairly large in the frame, and so one of the most likely to be a keeper, is to be in focus over the whole of the object (car, say) being photographed, it typically needs a smaller aperture than f/2.8. Since I use TAv for this sort of work, then that smaller aperture applies throughout, including the first frames. But the first frame has the object a long way away and small in the frame. Even though I'll probably be using 200mm for the first frame, there will probably be plenty of depth of field. So that smaller aperture won't be much of a test of AF over much of the burst.

In other words, the way I set and use the K-1 for fast moving objects in the field is significantly different from the way someone would set and use the K-1 to photograph a slow moving object for a review. And vice versa.

How relevant is a stringent test of a slow moving object (for a review) for indicating how good the camera is for shooting fast moving objects in real-world situations?

08-23-2016, 08:08 AM - 2 Likes   #32
Loyal Site Supporter
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 20,594
[EDIT - added]: At this point the horse is not only dead, it is glue. DPR has altered the review and no one will change the Conclusion or their opinion. Whatever damage shall have occurred has occurred.

A GOOD test is set up in a controlled, repeatable environment so that Data gathered accurately reflects differences in the tested subjects (the camera/lens combos); and such data has relevance to real world utility when tested subject results are ranked. Real world utility must be demonstrated (or the results are irrelevant). The ranking table thus becomes Information.

I contend the DPR test results are not Information and the conclusions are not supported. The results are merely raw data gathered.

What we learned from DPR is, if your use case is to slap a 36Mp FF dSLR and f/2.8 70~200mm zoom on a tripod and burst photograph a weaving bicyclist in uncertain lighting at f/2.8 and 200mm (using unclear camera settings), the Pentax combo will miss focus more than half the time.

I do not believe those specific parameters were used in any comparison test. As DPR stated, "The test evolved over time."

Ergo we do not know that any other 36Mp FF camera, or any other camera could achieve a higher in-focus score under those specific circumstances, and we surely do not know the K-1 tracking AF.C is "Poor. Not suitable for Action (small active children)".

Last edited by monochrome; 08-23-2016 at 08:40 AM.
08-24-2016, 12:38 AM - 1 Like   #33
Loyal Site Supporter
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 9,183
QuoteOriginally posted by FantasticMrFox Quote
I said that the K3 cannot do it (and I still assume it can't, because in contrast to the K-1 I actually own the K3).

Well, @FantasticMrFox , Biz-engineer has already provided sequences with the K-3 of one of the fastest birds in the world, check the whole page, worst possible case - Z direction movement as well:


https://www.pentaxforums.com/forums/190-pentax-k-1/319924-can-anyone-k-1-give...ml#post3624778


A few weeks ago at a trail running event I did, I - an ordinary, hobbyist photographer without skills - got out what should be a miserable combination.


Not a K-1, but an old, slow K-x. And used not a 70-200 SDM, but the unfashionable screwdrive 55-300 with long throw.


Single point, AF-C, in the Z-axis as well, carelessly shot, no tripod- if I can do this anyone can, and if DPR's camera experts can't reflect real world usage, they need to find another job.


I have happily shot runners, cyclists, football players, wildlife, and even put myself at the end of a runway and shot jet aircraft at landing speeds. There's a Russian pro who used a K-30 and screwdrive tele to cover motorbike races.

































Last edited by clackers; 08-24-2016 at 12:45 AM.
08-24-2016, 03:06 AM - 1 Like   #34
Veteran Member
Barry Pearson's Avatar

Join Date: Jul 2013
Location: Stockport
Posts: 870
QuoteOriginally posted by redpit Quote
I copy from the Ricoh official page here: K-1 | Ricoh Imaging

"Even when taking a panning shot, this system automatically detects the direction of the camera’s movement, and efficiently controls the SR unit to always produce the best image possible."

That made me trying both SR on and off panning shooting to conclude what works best for me. I am more confused than before after shooting two events

What I can verify though is that K-1 SR surely allows for some perfect panning shots when K-5IIs SR didn't. I don't know if it detects the horizontal panning movement and works in vertical stabilization mode only and I don't know if it can detect panning movement when handholding the camera (because slight vertical shaking-movement is inevitable).
I've been shooting lots of airshows and motorsports with the K-1 over the past few months. (Always hand-held). And uploading 100s of sharply-auto-focused photos from AF-C bursts to DPReview.

I've never yet switched off SR. I think the camera does that at even slow levels of panning. (I do get rejects that I put down to my own panning failures. I think that really means that the camera doesn't recover from my own shakiness).

08-24-2016, 03:37 AM   #35
Kiwi Pentaxian
Loyal Site Supporter
NZ_Ross's Avatar

Join Date: Mar 2012
Location: Timaru
Photos: Gallery | Albums
Posts: 3,283
QuoteOriginally posted by monochrome Quote
I contend the DPR test results are not Information and the conclusions are not supported. The results are merely raw data gathered.

What we learned from DPR is, if your use case is to slap a 36Mp FF dSLR and f/2.8 70~200mm zoom on a tripod and burst photograph a weaving bicyclist in uncertain lighting at f/2.8 and 200mm (using unclear camera settings), the Pentax combo will miss focus more than half the time.

I do not believe those specific parameters were used in any comparison test. As DPR stated, "The test evolved over time."

Ergo we do not know that any other 36Mp FF camera, or any other camera could achieve a higher in-focus score under those specific circumstances, and we surely do not know the K-1 tracking AF.C is "Poor. Not suitable for Action (small active children)".
I barely bother going to DPR to read anything these days.

I my opinion I find their reviews and opinion quite subjective and again, only in my opinion, I suspect they might be influenced by who owns them, and who pays the advertising bills.

I could of course be quite wrong in this, but for me I have increasingly found DPR to be a waste of time, effort and space.

I find the tone, friendliness, helpfulness, open and constructive discussions here at Pentax Forum much more to my enjoyment and taste than what I read at DPR.

So I am not at all surprised by your DPR observations and comments Monochrome.
08-25-2016, 06:52 AM   #36
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 7,290
QuoteOriginally posted by beholder3 Quote
SR was set to OFF. As I was swinging around the camera all the time it would not help and I wanted to switch everything off that would use valuable computing power/time.
I don't know at all if it helped. The whole event was about trying and learning after all.
Great!
I have "started" to use my K3 + DA*300/4 quite the same way (except for the AF back button) with the SR OFF for birding: results are better than with it ON. (shutter speeds at 1/800 s + ).
08-26-2016, 01:43 AM   #37
Pentaxian




Join Date: Dec 2011
Posts: 1,400
Original Poster
QuoteOriginally posted by jpzk Quote
Great!
I have "started" to use my K3 + DA*300/4 quite the same way (except for the AF back button) with the SR OFF for birding: results are better than with it ON. (shutter speeds at 1/800 s + ).
Glad it helped.
Note: I did not use the back side AF-on button but the one on that specific lens barrel (very handy), which can be pressed with the thumb of the left hand supporting the lens.
08-26-2016, 09:58 AM   #38
Site Supporter
Site Supporter
slip's Avatar

Join Date: Oct 2006
Location: 2 hours north of toronto ontario canada
Photos: Gallery | Albums
Posts: 3,534
QuoteOriginally posted by monochrome Quote
A test is not a test unless the aperture is f/2.8. Otherwise the plane of focus is far to deep to actually test the AF.



:brap:
agree. the lens needs to be wide open or its just a practice of shutter speed

Randy

08-26-2016, 10:15 AM   #39
Loyal Site Supporter
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 20,594
QuoteOriginally posted by slip Quote
agree. the lens needs to be wide open or its just a practice of shutter speed

Randy
OK. But you have to design a controlled, repeatable environment and rigorously stick to the test parameters or you can't compare performance acros camera/lens combos.
08-26-2016, 01:55 PM   #40
Veteran Member
Barry Pearson's Avatar

Join Date: Jul 2013
Location: Stockport
Posts: 870
QuoteOriginally posted by monochrome Quote
A test is not a test unless the aperture is f/2.8. Otherwise the plane of focus is far to deep to actually test the AF.
[Sarcasm]
QuoteOriginally posted by slip Quote
agree. the lens needs to be wide open or its just a practice of shutter speed
But if the aperture has to be f/2.8 for the test, what is it actually a test of?

If f/2.8 is not the aperture used in real-world situations, (and typically it isn't), then by definition a test that needs f/2.8 is not a test of real-world situations!
08-26-2016, 02:37 PM - 1 Like   #41
Site Supporter
Site Supporter
slip's Avatar

Join Date: Oct 2006
Location: 2 hours north of toronto ontario canada
Photos: Gallery | Albums
Posts: 3,534
QuoteOriginally posted by Barry Pearson Quote
But if the aperture has to be f/2.8 for the test, what is it actually a test of?

If f/2.8 is not the aperture used in real-world situations, (and typically it isn't), then by definition a test that needs f/2.8 is not a test of real-world situations!
if you flip it around, if you use F11 virtually any camera with enough shutter speed can stop the action.
I use F2.8 with my DA*200 lots with my K3 shooting baseball

randy
08-26-2016, 02:57 PM - 1 Like   #42
Loyal Site Supporter
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 20,594
QuoteOriginally posted by Barry Pearson Quote
But if the aperture has to be f/2.8 for the test, what is it actually a test of?

If f/2.8 is not the aperture used in real-world situations, (and typically it isn't), then by definition a test that needs f/2.8 is not a test of real-world situations!
It's expected that you test in 'lab conditions' and extend the results to assumed real world experience.

As I wrote upthread, a test must be controlled and repeatable, and the results must be demonstrably applicable to the real world. You have to test the assumptions to prove their applicability (since you can't test in real-world conditions, you have to prove your test is suitable to approximate them), as well as test the subject(s) to rank them. The much discussed test seems to have failed in all aspects, thus its conclusions cannot be deemed valid.

It's fine to have tested the K-1 at f/2.8 and 200mm on the 70~200. But the other cameras were tested at different apertures, at different focal lengths, in different light and object conditions (even using a 300/4), and on those tests any AF failure was dismissed 'expected'. K-1 was compared to a camera optimized for action AF and declared a failure.

The test was amateur science. The earlier post quote omitted the sarcasm tag in the quote.

Last edited by monochrome; 08-26-2016 at 05:09 PM.
08-27-2016, 01:13 AM   #43
Pentaxian




Join Date: Dec 2011
Posts: 1,400
Original Poster
QuoteOriginally posted by slip Quote
the lens needs to be wide open or its just a practice of shutter speed
Thanks for agreeing to this:
If you want to test the low light capabilities of a camera you have to test it on a evening scene using a 24mm F1.4 lens at shutter times of 1/4 second and longer, handheld.
Otherwise it's just a practise of lenses or tripods. Any camera with a tripod or a fast lens can get better. I can set up my compact on a tripod in low light and get decent results.

This very valid (the only valid) test setup proves, that the Sony A7s and the 1DXII and the D5 really suck at low light photography and are not even in the same league as a K-1 (or even the league below). The are so very far behind Pentax, one must wonder why their engineers suck so much at this easy task.

The review on these camera ends with:
"Con:
A7s/D5/1DXII suck at low light photography."
That's the scientific spirit of a rishi'd review.
And I have not seen any proof anywhere, which would suggest it is not this way.
08-27-2016, 12:02 PM   #44
Veteran Member




Join Date: Mar 2013
Posts: 339
QuoteOriginally posted by beholder3 Quote
  1. AF.C
  2. Sel-1 or Sel-9 (since the head of the driver is on the upper end I used the topmost AF point in the center column). If I had use a F2.8 lens like the 70-200, I'd used only one step upwards as only those middle three sensor are F2.8 enabled.
  3. Hold:Low
  4. AF.C priority 1st image: auto
  5. AF.C priority other images: auto
  6. JPG L*
  7. I explicitly turned off absolutely all other JPG corrections or automatisms.
  8. Used TAv mode all the time to set the aperture to open and set a certain time. Shutter times I experimented with anything between 1/320 and 1/4000 but mostly was stuck with very short ones due to the light and not having brought some NDs or at least a CPL. Generally I do not like to completely freeze dynamic subjects, so I prefer some blur on the wheels and with the dirt.
I'm not an action shooter and 99% of the time I'm in AF.S mode but I'm curious why you are not using expanded area AF modes?
Matter of habbit or something else?
I did some test with K-1 and all those modes works good for moving subjects.
08-28-2016, 03:48 AM - 1 Like   #45
Pentaxian




Join Date: Dec 2011
Posts: 1,400
Original Poster
QuoteOriginally posted by banep Quote
I'm not an action shooter and 99% of the time I'm in AF.S mode but I'm curious why you are not using expanded area AF modes?
I am not sure what you mean with "expanded area AF modes". I did write I sometimes chose Sel-9, which is one AF point helped out with the 8 points around it. I would call that "expanded".
So far I did not try auto-9, as I assume "auto" does not do what I want. But that is 100% prejudice at the moment, to be fair.

For horse racing I never choose even Sel-9 as too many horses are jammed together and passing each other all the time, so you have to precisely aim at the one you want to have in focus and consequently Sel-1 is the only way to go.

The less moving subjects you have jammed into the frame the more you benefit from using Sel-9 or even more.
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!
autofocus, burst, dslr, full frame, full-frame, garbage, images, k-1, k1, keepers, love, pentax, pentax k-1, results, shutter speeds, sr, ss
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nature Shooting garbage phoenixvision Post Your Photos! 3 11-04-2014 11:42 AM
Black & White Garbage Bag Porn iocchelli Post Your Photos! 6 04-07-2011 07:54 AM
Weekly Challenge #144 - Garbage wllm Weekly Photo Challenges 28 08-25-2010 03:38 AM
Garbage alohadave Post Your Photos! 8 07-24-2008 02:56 AM



All times are GMT -7. The time now is 06:53 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