hi all,

so, all i own is in my signature. and i gather that japan is a treasure trove of stuff. what should i set my eyes on?

seeing as i don't own any mega fast glass, i thought a new 50/1.2 would be nice.

and part of me is really toying around with the idea of replacing my 200/2.8 with a voigtlander 180/4 apo lanthar.

but, the truth is that i am generally happy with what i've got.

but i couldn't let a trip to japan go to waste, could i?

what other things are available in japan that aren't really available elsewhere?

i voted other. i would like to see two new things.

my biggest issue is having to wait for sr to kick in. i would like it to be near instantaneous. what i like to do when shooting at large apertures is to just hold the shutter down and let the camera fire exactly when the focus is completely nailed. this minimises photographer and subject movement. i can't do that with an sr delay.

one really cool feature would be automatic focus adjust done perfectly by the camera while being lens specific. i would love this feature to be added, and it's fairly simple, because most cameras can focus very accurately in liveview. so just mount the camera on a tripod, liveview focus, let the camera flip the mirror down, and the camera can see exactly whether it was back focussing or front focussing and make the adjustment for that lens.

it could make front and back focus an issue of the past.

i don't really want to compare the two directly, because i have no way of speaking of the 31mm ltd, since i've never owned one.

but i always held the sigma 30/1.4 in very high esteem. i shot one when i was with sony, and its optics were right up there with the best lenses i had.

don't want to cloud your decision-making too much, but i really see the 30/1.4 as an incredible value optic. i've opted for the 35/2.8 da limited for size considerations, but if i were in the market for a faster normal, then i'd go with the sigma again in a heartbeat.

they would hunt, but they'd try to focus, right? i just think it would be odd watching multiple systems trying to focus. i have no idea how the camera might manage such a thing.

i actually quite suspect the tc closest to the camera would do the focusing, in the same way that the tc disables lenses from focusing, the near tc would also disable the far tc from focusing.

i don't really fancy trying it, i was just curious.

although i actually have seen some ok results from stacked tcs. it seems to be highly dependent on the tcs and the order in which you stack them.

hi all,

what happens when you stack a 1.7x af tc on top of another 1.7x af tc?

do they both try to focus?

i can imagine that would be a bizarre thing.

but i find that my older lenses certainly had a markedly shallower depth of field at f/1.4 than at f/2. i'm talking of my old minolta 85/1.4 and a super-multi-coated takumar 50/1.4. i remember even doing comparisions on a digital sensor, and finding the depth of field markedly less at f/1.4 by about the amount you would expect.


i'm again not so sure about this. a sizeable proportion of current lenses are basically old film lenses with new coatings.

but, if indeed this effect seems as pronounced as it is, then this is a big advantage to the rear-illuminated sensor, as you mention.

i can't help but feel that there is more to this than has been said. the results from the exposure tests and depth of field tests don't seem consistent to me, given the current explanation.

yeah, sorry, i typed that very quickly.

i agree with what you say. it's the marginal light rays that focus to the edge of a circle of confusion, so give us more blur, and this should have been noticed more.

what i was trying to suggest was that these rays might be more or less perpendicular depending on whether these marginal light rays were from an object that was in focus or not. blind speculation on my part, and probably best ignored for the purpose of the argument.

but i agree with you. the depth of field effects are undeniable, imo. but algernon's exposure tests seem pretty convincing to me also, as does my own experience with the metering of manual glass.

in short, i'm pretty confused.

i follow what's going on, but i'm still intrigued by this statement from mark dubovoy over at ll

the depth of field effects are significant at large apertures, in my opinion. i have owned 3 f/1.4 lenses, and found this to be the case with all of them. there's no denying this effect of shallower depth of field at larger apertures. so what's going on there? perhaps out of focus areas strike the film plane more perpendicularly than in focus areas? i'm no optical engineer, so i can't explain.

i don't see this so much as a fault of manufacturers so much as a hurdle of digital sensors. i imaging the angle of light hitting the sensor will become a more important aspect of lens design, or perhaps not, since compromising with iso seems to have gone unnoticed for so many years...

40mm is excellent. i had one, but swapped it in for the 35mm, which is equally excellent, but focuses a bit closer.

70mm is really good too, but my only gripe is that it doesn't seem quite so stellar at infinity as it does at intermediate and closer distances. still great throughout the range, though.

but the 40mm is a serious piece of work—to pack that performance into that size is really something. enjoy it! but don't lose it, accidentally, because, you know, it's pretty small...

thanks for the tip. i had followed that. i am actually heading to japan later in the year, and am thinking about what i should have on my hit list. nothing as big as a k-5, but something i might be able to get a good price on. perhaps something as simple as an fa 50/1.4 might do as well.

but that voigtlander bokeh is incredible....