JR & Jerry,
Nice to see other people actually change air pressure and run times according to material!! :) ..This drives me CRAZY, I have been in one lab "fixing" cylinder machines and "trying" to show the tech the problems..the complaint is the lens is picking up waves... and all three times I went in they have the pins set at 30 pounds...that's right 30lbs!! and the run time is 2 minutes on the first and second fine... I'll turn it down and try to explain with that much pressure you are generating a TON of heat as well as that long you are picking up every imperfection in the tool to compound the problem even further.. the tech turns it right back up after I leave says the same thing "well that is the way I learned to do it" ...gee you would think they would get tired of paying me $45 an hour to keep coming back and telling them the same thing over and over...
You know thinking about it, it could be that the problem shutterbug mentioned as well and the reason the re-running is working on a foam block is they are applying a new pad :) .. I hope Chris is looking at everyones post and doing some elimination to get to the problem..BTW further up the thread I also prefer Dac's striped pad system as well...
Susan,
No one can ever ask a "dumb bunny" question :) .. this is the stuff we lab rats thrive on :) .. JR answered your questions about the marks and swirls but I'll answer about inspection... most often the higher the amount of production the less inspection is done.. usually it's checking powers.. and if they are using a digital analyzer than things like swirls or waves can be passed a long without being found... it depends on the lab usually and how they go about checking.. all my guys visually check for waves before popping them onto the lensometer, and the person doing the deblocking I have a light set up with a dark background and as they deblock and wash the lens off they are in the habit of holding the lens up and checking for any scratches or swirls and waves before moving over to the final check of power.. mainly it's for saving time and the guys doing the deblocking can spot if we have a problem right than and trace back to where the problem might be...most often, wrong tools, polish etc., etc.
It still amazes me that some labs just do not look at the big picture and shove things through and forget that each account looks at it as THIER work is all they care about.. you push slop through and waste a day or so shipping than they get the lens and have to call and reorder, the account is usually not to thrilled :)
I'll not claim that a "bad" lens sneaks through ever so often but I have about the best inspection system I can think of and three different people doing the checking so one may miss but all three? not very often.. Quality control should be a very important part of the process, but sometimes that is not as important as "prices" in todays market.. you want them cheap as possible but still perfect? .. those two things do not always work well together in every lab :)
Jeff "gee us lab rats just love to tinker" Trail
Nice to see other people actually change air pressure and run times according to material!! :) ..This drives me CRAZY, I have been in one lab "fixing" cylinder machines and "trying" to show the tech the problems..the complaint is the lens is picking up waves... and all three times I went in they have the pins set at 30 pounds...that's right 30lbs!! and the run time is 2 minutes on the first and second fine... I'll turn it down and try to explain with that much pressure you are generating a TON of heat as well as that long you are picking up every imperfection in the tool to compound the problem even further.. the tech turns it right back up after I leave says the same thing "well that is the way I learned to do it" ...gee you would think they would get tired of paying me $45 an hour to keep coming back and telling them the same thing over and over...
You know thinking about it, it could be that the problem shutterbug mentioned as well and the reason the re-running is working on a foam block is they are applying a new pad :) .. I hope Chris is looking at everyones post and doing some elimination to get to the problem..BTW further up the thread I also prefer Dac's striped pad system as well...
Susan,
No one can ever ask a "dumb bunny" question :) .. this is the stuff we lab rats thrive on :) .. JR answered your questions about the marks and swirls but I'll answer about inspection... most often the higher the amount of production the less inspection is done.. usually it's checking powers.. and if they are using a digital analyzer than things like swirls or waves can be passed a long without being found... it depends on the lab usually and how they go about checking.. all my guys visually check for waves before popping them onto the lensometer, and the person doing the deblocking I have a light set up with a dark background and as they deblock and wash the lens off they are in the habit of holding the lens up and checking for any scratches or swirls and waves before moving over to the final check of power.. mainly it's for saving time and the guys doing the deblocking can spot if we have a problem right than and trace back to where the problem might be...most often, wrong tools, polish etc., etc.
It still amazes me that some labs just do not look at the big picture and shove things through and forget that each account looks at it as THIER work is all they care about.. you push slop through and waste a day or so shipping than they get the lens and have to call and reorder, the account is usually not to thrilled :)
I'll not claim that a "bad" lens sneaks through ever so often but I have about the best inspection system I can think of and three different people doing the checking so one may miss but all three? not very often.. Quality control should be a very important part of the process, but sometimes that is not as important as "prices" in todays market.. you want them cheap as possible but still perfect? .. those two things do not always work well together in every lab :)
Jeff "gee us lab rats just love to tinker" Trail
Comment