PDA

View Full Version : dof adapter and chromatic aberration



ph2003
2010 March 10th, 04:46
hi guys,
finally got all the parts for my adapter.
its still on static atm (still doing the wireing stuff) :hv20-smilie126:

i attached 2 images which 1 w/o condenser (it looks darker)
and other 1 with condenser (color is brighter but having the chromatic aberration effect, it only appear at the outer frame and distorted too.)

is this is normal that all condenser will produce chromatic aberration like this
and using an achromatic lens to reduce it?
now im only using the cheap +10 macro lens (which i bought from ebay)

i have another 40mm achromatic optic(a gift from sirjoe, he told me it will reduce chromatic aberration, but i couldnt test yet)
which i havent make the holder (still waiting on the uv filter to make holder :mad:)
i duno if the 40mm is enuff or i should get the 58mm opteka +10?


thanks in advance!

CorbenT
2010 March 10th, 14:06
The CA which you are getting is extreme. Have you got the right distance between the condenser and the GG? It should be no more than 15mm. I have heard of people using achromats as condenser lenses, which in theory would reduce CA, but from my experience a DCX lens should work very well.

ph2003
2010 March 10th, 22:35
hi CorbenT,
yeah u r right. i got the wrong distance between gg and condenser :hv20-smilie119:

it was like 20-30mm (because i was planning to place the wire connector between gg and condenser:hv20-smilie87:)
lucky i havent drill the hole yet, i just got it fix to 10mm (the closest i could get now)
i just recheck sirjeo website, he did says distance should be 5-10mm too (im dump didnt saw this:hv20-smilie15:)

it still had some CA, u think this should be ok after placing the right achromat?

btw im using DCX condenser too (with the flatter side facing the GG)

thanks!

Shigeta
2010 March 11th, 01:27
Btw, you should invest in a different achromat (+10)

Those +10 filters don't do quite the same job. Get an opteka.

ph2003
2010 March 11th, 02:07
hi Shigeta,
i have another +10( i think its around +10, check the image i attached )
its from sirjeo :) but its only 40mm.
did it worth me using some money to do the holder or just save the money for an opteka :hv20-smilie50:

PS: i think it should be this cheap macro lens cause the CA.
i do some more test on this macro lens, it did have CA w/o using the DCX.
actually the image 1st post have CA on it too (maybe the vignette is too strong w/o DCX, so barely can see the CA in it)
here is another cropped part that show extreme CA.

thanks!

wdd69
2010 March 11th, 04:20
my filmpro35
http://exposureroom.com/members/paooo001/91fee78e1213492dac52fc1b9402b31a/

sirjoe
2010 March 11th, 08:59
Hey,

My advice would be the same as already posted. Get the condenser a bit closer to the screen, and think about getting an achromatic.

I included one for free for you to try out, but it is only a 7+, should be enough though.

I recommend the opteka ones if you can afford them the housing is worth it.


Sirjoe

ph2003
2010 March 11th, 11:12
hey sirjoe, i will get the opteka then :)
lucky i havent order the parts to make holder for achromatic u gave me XD

only amazon have it though, couldnt find any from ebay :(
is this the right 1? link here

thanks!

sirjoe
2010 March 11th, 14:31
Yep, thats right.

ph2003
2010 March 12th, 02:25
hey guys!
i tried ur 40mm achromatic, cost me like usd0.5 to make the holder :hv20-smilie87:
the result is much much better:hv20-smilie77:
vignette is almost disappear and CA was reduced:hv20-smilie70::hv20-smilie45: (check out the attachment)
i think i will stick to this quality atm untill i got a way to get opteka for cheaper ship.

sadly... i gave up to get the opteka........:eek::eek::eek::eek:
i just tried to order from amazon.... the shipping fee sucks so much on amazon :( 2x of the opteka price... usd60 to ship to me.:hv20-smilie119:
idk why it cost so much... the higest ebay only cost me like usd35 :hv20-smilie51:

total price will be usd90...
the canon fd 50mm 1.8 only cost me usd20

thanks!