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10-07-2014, 06:11 AM - 1 Like   #166
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QuoteOriginally posted by jsherman999 Quote
I've commented on your site itself - didn't do much good, you discounted what I had to say. I've talked to you here several times - absolutely no effect, physical reality seemed to take a holiday. I did ask the mod team over there why you were banned and they said it's because you were behaving like a 12-year old... which you've been doing here as well.

Here, I'll let bobn2 answer your "what's wrong with my article" question, I've already tried to no avail (bobn2 = physicist, owner/creator of sensorsgen site.)
I don't think he is as big of an idiot as he comes across on the internet. He's just trolling trying to drive hits to his personal blog. Everything he says is for the purpose of getting people to click through.

10-08-2014, 03:37 PM   #167
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Just for grins I de-Ignored the Full Frame Forum. I chose this thread to read. You guys really put up with this?

It's waaaaaaaay beyond me on my worst day in K-01 time.

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10-08-2014, 04:19 PM   #168
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QuoteOriginally posted by monochrome Quote
Just for grins I de-Ignored the Full Frame Forum. I chose this thread to read. You guys really put up with this?

It's waaaaaaaay beyond me on my worst day in K-01 time.

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It is rather astounding, even for me...
10-08-2014, 11:14 PM   #169
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QuoteOriginally posted by dtmateojr Quote
ROFL! That's it? So your explanation of how f-stop works is by giving me a definition? Something is very wrong with you. No wonder why you stopped teaching.
What good does it do to you trying to force your opinions onto others? Browsing around the forum I find you on many threads basically calling other people stupid not believing the same way you believe. That's pretty much the same thing as trying to force someone's religious beliefs onto others. Being rude and offensive gets you nowhere. If somebody doesn't agree with you, please allow him/her to do so. They have the right, you know. Just like you have. Most of us just don't try to force others into believing like they do. Endless arguments ruin every meaningful discussion. And most of us are here to discuss and SHARE opinions and experiences.

Take some pictures for a change.

10-10-2014, 06:09 AM   #170
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The thing that is bothering the most with Pentax is the slow roll out or lack of Third party lenses.
Sigma was supporting for some time but not clear going forward.
I really like Tammy 150-600, but not in Kmount.

I have been a pretty die hard supporter of Ptax but lately I have held back any investment to see what happens next. The Last lens I bought I did for a trip to Italy and that was the Sig 18-35 (GREAT). but short of that need, I cant justify more investment as I getting to feel that I am in a dead end. I have been tempted to pull the trigger on the K3, but have held back because of that.

Sony is looking good for APSc and FF and for smaller cameras I like m4/3.
10-10-2014, 06:23 AM   #171
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QuoteOriginally posted by spartan Quote
The thing that is bothering the most with Pentax is the slow roll out or lack of Third party lenses.
Sigma was supporting for some time but not clear going forward.
I really like Tammy 150-600, but not in Kmount.

I have been a pretty die hard supporter of Ptax but lately I have held back any investment to see what happens next. The Last lens I bought I did for a trip to Italy and that was the Sig 18-35 (GREAT). but short of that need, I cant justify more investment as I getting to feel that I am in a dead end. I have been tempted to pull the trigger on the K3, but have held back because of that.

Sony is looking good for APSc and FF and for smaller cameras I like m4/3.
I notice you support Pentax but you bought the Sigma 18-35, not the Pentax 20-40. So it could be stated with equal authority that you no longer support Pentax, and you're just the last one to realize it. Pentax is the champion of light weight portable lenses. If you are Interested in big heavy, heavily corrected lenses? That's not Pentax, at least not at this point in time.
10-10-2014, 06:52 AM   #172
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QuoteOriginally posted by spartan Quote
I really like Tammy 150-600, but not in Kmount.

...

Sony is looking good for APSc and FF and for smaller cameras I like m4/3.
Does not follow, Spartan.

Your specific example was the Tammy, and it's not available in m4/3 while the Sony version doesn't have VC.

Have fun with a 600mm lens on an A7, probably through an adapter, without shake reduction!
10-10-2014, 07:51 PM   #173
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QuoteOriginally posted by normhead Quote
I notice you support Pentax but you bought the Sigma 18-35, not the Pentax 20-40. So it could be stated with equal authority that you no longer support Pentax, and you're just the last one to realize it. Pentax is the champion of light weight portable lenses. If you are Interested in big heavy, heavily corrected lenses? That's not Pentax, at least not at this point in time.
Norm

I have bought plenty of Pentax equipment over the years... DA* lenses, flash, GPS etc. Also I have been a very active supporter on various fora including Consumer reports.

I bought the sigma because is an excellent, fast wide angle zoom. The DA limited zoom is not quite in the sweet spot for low light and not quite wide enough. And about the same price as the Sigma. Sigma is putting some great lenses now and are slow to bring them to K mount.

10-12-2014, 12:38 AM   #174
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You could always have two systems if money allows. I decided to keep my K5/K200D/K100D IR and just my favorite and most used Pentax lenses and sold the rest to invest in a Sony A7. I can still use many of my pentax lenses on the A7 via adapters. I think both APS-C and FF have a place in my arsenal and I believe Pentax is the best when it comes to APS-C and the Sony A7 is a great opportunity to use both their high end Zeiss lenses and older Pentax lenses on FF. To each their own I guess.

I would never try 600mm on a A7 handheld....hell even with SR on a pentax I wouldn't try it, thats what tripods and remote triggers are for.
10-17-2014, 10:49 AM   #175
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QuoteOriginally posted by rawr Quote
I was disappointed a while ago to see that the D600/D610's autofocus was only rated to work down to -1 EV - just like the K-x and K-5. So the D600/610 were probably never the best choice for indoor low-light.

D750 and the 6D, on the other hand, do -3 EV autofocus, just like the K-3 and K-5II, so probably fit the bill better for indoor low-light.
autofocus isnt the issue, the d600 is fine -- its just i expected a jump in IQ and im not really seeing it over the K01 and i think my fuji x-a1 is even better then the D600.
10-17-2014, 01:42 PM   #176
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I think my D600 is far superior to my K-5 in IQ.
10-18-2014, 03:08 AM - 1 Like   #177
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QuoteOriginally posted by dtmateojr Quote
If you only care about DoF then you will feel that way. A f/2 is a f/2 in terms of light and to real photographers that's what matters the most. I don't think you can buy a 70-200 f/2 full frame at all.
f/2 is f/2 in terms of light density, not the total amount of light collected.

f/2 on different formats turns out different image - a cell phone camera at f/2 captures little light, thus also hase deep depth of field, while an APS-C with the same field of view has much more shallow DOF and also captures much more light and a FF captures still more light and has more shallow DOF.

If the field of view, shutter speed and aperture number remain the same, then the bigger the sensor, the more shallow the DOF and the more the sensor collects and the better the signal-to-noise ratio of the image will be.

---------- Post added 18-10-14 at 13:16 ----------

QuoteOriginally posted by dtmateojr Quote
So why compare f/2 and f/4? That's two stops of difference.
And be more specific and say you care only about shallow DoF
f/2 on one format equals f/4 on a different format.

Lets consider idealised systems - a perfect lenses and perfect image sensors. Let's compare two systems:
  1. Full frame (FF)
  2. Crop with crop factor of 2 (C2)
For the same field of view (ie. FF with twice the focal length) if the FF has twice the aperture number than the C2 has, the images the cameras will create will be identical. The same noise, the same DOF.


If you use the same exposure settings, then FF image will have more shallow DOF, but also signal to noise ratio twice as good, thus much less noise.

---------- Post added 18-10-14 at 13:19 ----------

QuoteOriginally posted by dtmateojr Quote
I don't want to go down that rabbit hole but that is BS. But in case you are interested:

Debunking Equivalence | Demo Mateo
Anyone interested in factual content should avoid that site.

Equivalence as defined by for example Great Bustard of DPR forums is very real tool consistent with the laws of physics.

---------- Post added 18-10-14 at 13:24 ----------

QuoteOriginally posted by dtmateojr Quote
Ask the mods. They "featured" an article that was purely wrong and stupid and they didn't want them to be exposed. Have a read on that article and see how many photographers are mocking it.

Can you defend your equivalence-fu or are you no different to the other fauxtogs in dpreview?
The reason why you were banned was your extraordinary impolitelness. You were very rude and kept on insulting people. It had nothing to due with your arguments.

Do you seriously think that you were banned because of your "secret knowledge" which should not be posted on DPR-forums because it would embarrass DPR in some way?

---------- Post added 18-10-14 at 13:32 ----------

QuoteOriginally posted by dtmateojr Quote
Then you do not understand f-stop at all. If you do not understand f-stop then you do not understand exposure. Ergo you do not understand photography.

For the record, aperture is NOT THE SAME as f-stop. Aperture by itself does not explain exposure. You are completely ignoring the effect of focal length. I will not attempt to educate you further. You are very deep down the equivalence-fu rabbit hole like that guy sherman. Getting out of that trap is worse than changing religion. I advise you to stay where you are and continue believing the BS.
This is precicely the kind of language that got you banned from DPR. It is hard to imagine you'll be tolerated here for long either if you keep this up.

Anyhow, regarding equivalancy:

  1. If one captures twice the light, the signal doubles and the noise increases by factor of sqrt(2). This is basic physical fact that comes from the quantum mechanical nature of light - it's probability function collapse obeys poisson distribution.
  2. It doesn't matter how you capture the extra light - it may be captured by having a larger aperture (not aperture number, but the diameter of aperture) or by exposing longer
  3. For any field of view the bigger sensor requires longer focal length, thus as aperture diameter is f/#, ie. focal length divided by aperture number, more light will be collected if the aperture number is the same.
If you want to combat equivalency, you should involve the mathematics of SNR to it - unfortunately those don't support your position so I'm not expecting them to appear.

---------- Post added 18-10-14 at 13:55 ----------

QuoteOriginally posted by dtmateojr Quote
So where did I say that f-stop is dependent on sensor size? In fact, I have stated exactly that f/2 is f/2 regardless of format.



---------- Post added 10-07-14 at 19:01 ----------

It's really funny 'coz a lot of fauxtogs here say that I'm wrong and yet they can't even provide any counter-arguments.
The problem is that you don't read or consider the the counter arguements. After a while no one bothers to counter you as you keep repeating your ever unchanging message regardless of it's factual incorrectness.

Like the f/2 is f/2 regardless of format. Please take a picture with a cell phone at f/2 and then with your "real camera" an image with the same field of view, and tell me if the f/2 on that gives the same DOF and SNR or not?

It is trivial for you to test your hypothesis, but you don't do it but rely on your reasoning inspite the evidence contradicts it.
If you only have one camera, then do this (adapt according to your lens lineup): take picture at 25mm and f/2 and a picture at 100mm and f/2. Crop the 25mm image to match the FOV of the 100mm (to simulate a crop-factor). Then present the images at the same size and analyze the results and tell us what you see. Please do this. We might all learn something.
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