Is the EM5’s Miss-Stated ISO concerning to you?

Started 3 months ago | Discussion thread
Anders W
Forum ProPosts: 10,784
Like?
Re: Is the EM5’s Miss-Stated ISO concerning to you?
In reply to DonSantos, 3 months ago

DonSantos wrote:

DonSantos wrote:

Here are the arguments.

On one side:

Iso doesn't matter. It's a bourgeois concept.

I'm going to spew some technical gargon that will confuse you about jpeg gain and dxo measurements of saturation blah blah blah. raw doesn't matter blah blah. confuse the reader even more so they are convinced they don't need to care about overstated iso

Omd is god. Don't you dare talk bad about it. Everything they do is right.

On the other side:

I want some to compare cameras with an even baseline exposure. If the stated iso isn't similar than I can't make fair judgements using image comparison tools.

Here is the simple solution for dpreview: Iso does't mean anything. It's all about the exposure.

1. use a constant f-stop.

2. instead of iso split out the images by shutter speed.

3. use a controlled lighting setup measured by a light meter.

It's so easy. Comeon dpreview. Your (raw) comparison charts are flawed and favor overstated iso camera.

No they don't favor certain cameras over others on such grounds. If you think so, you are simply misinformed.

If you think you can infer the effective exposure (amount of light on the sensor) from the f-stop and shutter speed used by DPR for their studio scene samples you are wrong. Any such inference assumes that the light level is constant from one time/test to another. DPR has made it clear that this assumption is false.

DPR use other procedures to ensure that their studio scene samples are as comparable as possible.

btw I've did test comparing the d600 and the fuji x100. The fuji x100 is definitly overstating their iso by 2/3 of a stop. This is exactly in line with the dxomark iso sensitivity measurements. I really trust their methods.

I'll give you a real example. In the exact same scence with the same f stop and shutter and visual brightness to my image my x100 over states the iso by 2/3 stops compared to the d600 which is exactly what dxo says it would do. That means I can't compare say 3200 in x100 to 3200 in the d600. I have to compare iso 3200 iso on th x100 to iso 2000 on nikon.

Exactly how do you go about it to determine that the x100 overstates the ISO by 2/3 EV compared to the D600?

If anyone disagrees then they have flawed logic.

iso should not be that base of comparisons the "amount of light captured" should be the base.

Again its not diffucult for dpreview to use a light meter to control their lights. that way we can get accraye comparisons regardless of iso

They do use a light meter to control their lights when checking the extent to which a camera meets the ISO standard. Once they know that, they don't need a light meter for their studio scene samples. They just need to expose such that an 18 percent gray target reaches the correct brightness in the OOC jpegs.

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow