GH2 official discussion thread

SteB said:
One of my interests in the extra tele conversion feature is the possibility of using it for macro video as I do a lot of macro photography stills. The extra tele-conversion feature will increase the 1:1 max magnification of most macro lens to 2.6:1 in 1080 and a serious 3.9:1 in 720. Also it will enable you to get near macro performance from an ordinary lens with a reasonable close focus. The extra depth of field will be a big advantage. However, the downside is that with this effective size of sensor is that the diffraction limited range of the lens performance will start much earlier i.e. at a wider aperture. Because this is a 100% portion of the sensor, with no down-sizing, diffraction could soften the video image. This would also be a problem with other lenses as the small size of the sensor means that diffraction effects could start before f5.6 - so ideally the lenses and apertures used need to be wider than when using the full sensor. This is normally why lenses for smaller sensors have wider apertures, because they do not perform well at small apertures due to diffraction. Of course this is only relevant if the extra tele conversion feature is being used. It would also mean that the diffraction effects would kick in earlier using 720 than it would using 1080. So it is worth bearing this in mind if you are used to a particular lens when using the full size of the sensor as the effective focal length and the depth of field are not the only properties effected when using a smaller portion of the sensor.
Click to expand...

Diffraction effects are affected by aperture and individual sensor (R,G, or B) size and picture resize (if present).
So, diffraction in tele-conversion will be the same as in full photo mode.
Compacts have much more pronounced diffraction due to large megapixel sensors.
But, of course full mode video will have less diffraction visible due to picture downsizing.
 
Vitaliy Kiselev said:
Diffraction effects are affected by aperture and individual sensor (R,G, or B) size and picture resize (if present).
So, diffraction in tele-conversion will be the same as in full photo mode.
Compacts have much more pronounced diffraction due to large megapixel sensors.
But, of course full mode video will have less diffraction visible due to picture downsizing.
Click to expand...

I hate to disagree with you on this. Diffraction is a lens effect and the degree of diffraction at a given aperture is determined by the sensor dimensions and not the resolution of the sensor. If a still image is reproduced to the same physical print size the diffraction effects are the same regardless of the resolution of the sensor - providing the sensor is the same dimensions. It is only said that the diffraction is more pronounced on higher resolution sensors because it effectively limits their potentially higher resolution at certain apertures. A higher resolution sensor does not resolve less than a lower resolution sensor due to diffraction. The smaller the sensor the earlier the diffraction limited zone in a lens' aperture range. The diffraction effects on small sensored compacts are related to the sensor size and not the resolution of the sensor. Normal full sensor video has the depth of field and diffraction effects of a 4/3 sized sensor. This is because the video frames are taken from the full sensor and downsized to these dimensions. Whereas in the crop mode the sensor is effectively much smaller and the depth of field and diffraction effects are determined by the effectively much smaller than 4/3 sized sensor - diffraction effects would be greater in 720 than in 1080. At 4/3 sensor size you will get reasonable performance at quite small apertures like f16, but f16 or smaller in the crop mode is likely to produce noticeable softening of the image due to diffraction effects.

To explain it from a different angle that might make more sense. The image projected onto the sensor is softened at small apertures due to diffraction. The resolution of the sensor just determines the frequency of which the image projected by the lens onto the sensor is sampled at. So a higher resolution sensor will have its ultimate resolution effected more due to diffraction than a lower resolution sensor. However the actual sensor sized portion of the projected image from the lens is softened by diffraction to the same extent, if the aperture is the same.

I think we might actually be saying the same thing. The diffraction effect on full sensor images in video will not be very noticeable due to the oversampling and loss of resolution in downsizing. However, in the crop mode the diffraction softening will be more visible as there is no oversampling effect due to downsizing. This will be on top of the normal diffraction effects. I am only so familiar with diffraction effects because in macro photography you always have to draw a fine balance between enough depth of field and not too much diffraction softening from using too small an aperture.
 
Ian-T said:
Sheesh.....it's like Yoda rose from the dead just to write reviews. :)
Click to expand...
Japanese tends to trip up software translations in a lot of ways. There are no word breaks and an insane number of homonyms (requiring context to decipher). The sentence word order is Subject-Object-Verb, with the subject usually left out. That means the software must try to convert the words into passive voice, while reconstructing the sentence into English word order, while preserving the intended meaning. To top it all off, this writer uses a lot of wordplay and casual idioms.
 
Last edited:
can someone explain the language issue with buying a Japanese GH2 model?
why can't i change the language? is it a firmware thing? a permanent hardware? why???
what else is different between the same product they sell in each country (except for PAL of course)?
 
Here's a handy diffraction effect calculator:
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

I'm no optical engineer by any means, but I ran some quick numbers through this calculator and got the following results:

1080P:
– GH2 1:1 pixel, EX Teleconverter mode (7.2x4.0mm): Smallest aperture before diffraction limit: f/8
– Micro 4/3: Smallest aperture before diffraction limit: f/18
– 1.5x crop APS-C: Smallest aperture before diffraction limit: f/22
– Full Frame 35mm: Smallest aperture before diffraction limit: f/32

10MP:
– Micro 4/3: Smallest aperture before diffraction limit: f/8
– 1.5x crop APS-C: Smallest aperture before diffraction limit: f/11
– Full Frame 35mm: Smallest aperture before diffraction limit: f/16

16MP:
– Micro 4/3: Smallest aperture before diffraction limit: f/5.6
– 1.5x crop APS-C: Smallest aperture before diffraction limit: f/8
– Full Frame 35mm: Smallest aperture before diffraction limit: f/13
 
Last edited:
I'm not 100% sure, but you maybe able to change it to English language (or another) once they release a firmware update. This could be quite some time, although updates usually do come quite soon after a new release, to iron out some release bugs (or complaints).
 
teuron said:
is there, or will there be a vertical grip / AA battery pack for the GH2? (similar to the canon offerings for all their cams)

im interested in something that i can take out into the bush for a couple of weeks where i will not be able to recharge any batteries and will be filming extensively and i cannot afford to buy a whole bunch of proprieties.
Click to expand...

AFAIK, Panasonic makes no AA battery pack. You're probably better off with a Canon or a Nikon D7000. Also, the 60D, 7D & D7000, all have rated battery life that's about 3X longer than the GH2's for stills, though the gap should narrow if you're shooting video. FYI, the GH2's battery is rated at 1200 mAh. The D7000's battery is rated at 1900 mAh. The 60D & the 7D battery is rated at 1800 mAh.
 
Last edited:
You might consider investing in a solar panel recharger - there are small, portable, flexible, foldable ones ....
 
Well the ones with the correct voltage and amperage to charge GH2 batteries may not be that cheap - but yes they are cool!

Edit: they aren't slow if you get a biggish one with lots of ompff! :)
 
GrahamH said:
Well the ones with the correct voltage and amperage to charge GH2 batteries may not be that cheap - but yes they are cool!

Edit: they aren't slow if you get a biggish one with lots of ompff! :)
Click to expand...

Do you have a link to some good solar chargers? I'm all about having the sun pick up the costs instead of my local utility company.
 
Etown Mark said:
Do you have a link to some good solar chargers? I'm all about having the sun pick up the costs instead of my local utility company.
Click to expand...

We are veering off thread topic here ... might be best to start a new thread to discuss. And this GH2 forum actually may not be the most productive place - does DVXUser have an equivalent to DVInfo's "Under Water, Over Land' forum?
 
I heard Japanese domestic bodies are usually better in quality. They have higher resale values in Asian countries. That applies to all other major brands. Time to learn Japanese? :)
 
stonebat said:
I heard Japanese domestic bodies are usually better in quality. They have higher resale values in Asian countries. That applies to all other major brands. Time to learn Japanese? :)
Click to expand...

ok.. well i think the price is a bit higher (1000$ for body only)...
if the language is only a firmware issue then i can live with that for a bit.
anyone going to japan? :)
 
You must log in or register to reply here.
Back
Top