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Forum: Pentax K-1 & K-1 II
05-08-2018, 12:29 PM
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The poster I was quoting was talking about you putting the same lens on multiple cameras and I was pointing out it was a fixed lens camera so at least one of the cameras can't be used with the same lens. Also Ricoh GR color may not be the same as Pentax K-1. The only reason I brought up the GR was for people unfamiliar with the Coolpix A to understand the type of camera it is.
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Forum: Pentax K-1 & K-1 II
05-08-2018, 07:06 AM
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The Coolpix A is a fixed lens camera similar to the Ricoh GR.
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Forum: Pentax K-1 & K-1 II
05-07-2018, 09:34 AM
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I'm going to take a stab at this.
Nikon Coolpix A vs. K-1 - what's different:
Sensor
Lens (T stops)
Metering Logic
Metering Sensors
Maximum F stop
Filter
What's the same:
Both take pictures
Both have a 28mm FOV using the lens in question.
Which factors affect the exposure at the time of taking:
Sensor
Lens (T Stops) (1/2 to 1/3 stop likely)
Metering Logic (1 stop roughly)
Metering Sensors (?)
Maximum F stop
Filter (2 stops)
ISO
Shutter Speed
Aperture
Honestly I think the OP is very confused and looking for help understanding what is essentially a non-existent issue. I have seen several questions asking about the faster lens and I think it has been said a few times but I will repeat it. At any f stop the only differences between the lenses are the T stops (1/2 to 1/3 stops likely) so the Nikon at f/2.8 and the Zeiss at f/2.8 are the same the Zeiss isn't any faster once you stop down to f/2.8 - it offers the option to go wide open which could help you take pictures in lower light but it does not act any differently once you stop down. The same goes for the full frame sensor - the extra sensitivity and the ability to shoot at higher ISO with less noise means you can use it in lower light - but if you shoot in good light and have the ISO the same - there is no actual gain to be had in overall exposure. Yes you might see less noise but that's not the measurement being discussed. Lastly, Nikon has often underexposed ISO 100 in the past. Tests by lots of reviewers have shown this. I do not know for sure if the Coolpix A does but it could. It isn't important in the long run.
Set both cameras to manual and do a series of exposures at various ISO's and shutter speeds and apertures and see what the overall results are. Make sure both are filterless.
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Forum: Pentax K-1 & K-1 II
05-06-2018, 08:21 AM
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I think the title is misleading. The main problem seems to be a 5 stop difference at the same iso. Seems really off. I'd guess something is set different.
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Forum: Pentax K-1 & K-1 II
05-06-2018, 07:31 AM
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Oh lol. Like the GR. I forgot. So 18mm roughly right?
---------- Post added 05-06-18 at 10:32 AM ----------
I need to wake up today!
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Forum: Pentax K-1 & K-1 II
05-06-2018, 07:05 AM
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Since one is 28mm on apsc and the other is 28mm on full frame the second shot should take in a wider perspective. This could be related to how the two metering programs saw the scene.
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Forum: Pentax K-1 & K-1 II
05-06-2018, 06:19 AM
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Post the shots with full exif when you can.
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Forum: Pentax K-1 & K-1 II
05-06-2018, 06:12 AM
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Did you have them at a similar angle of view? Did both images take in the same scene edge to edge? If one was wider or narrower the metering could be with different unless you use spot metering since the matrix style pattern metering can vary based on scene composition. (also I edited my post adding a number 5 btw).
---------- Post added 05-06-18 at 09:13 AM ----------
I missed that. Sorry.
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Forum: Pentax K-1 & K-1 II
05-06-2018, 06:05 AM
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1) I never saw you mention the ISO used are both cameras set to the same iso? The exposure depends on three factors one of which hasn't been explicitly stated.
2) metered results may vary depending on the program intent. If you really want to compare you should use manual mode on both.
3) as stated, fast lens is only faster at wider f stops. The lenses would be equivalent at the same f stop in terms of exposure.
4) exposure doesn't care about sensor size, but the ladder sensor will generally be able to go to a higher ISO without losing quality, the individual pixels are typically larger and have more light reach each one.
5) T stops are a real thing. T stops are calibrated to take into account light losses for to lens design. F stops simply compare aperture diameter to focal length. However the difference is generally under 1/2 of a stop. That difference mainly is noticed in Cinema when a filmmaker uses multiple lenses in the same scene and doesn't want minor brightness differences to complicate editing, particularly with film.
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