I have a Devere 504 with the ilford multigrade system - I've noticed that that the 150 lens for enlarging - the image stays in focus for the whole session printing, but if I switch to the 80mm and printing, it goes out of focus very quickly, have to check it every time I make a print, can even go out of focus while printing - especially troublesome for large prints with long exposure times. Has anyone had this before?
I have a Devere 504 with the ilford multigrade system - I've noticed that that the 150 lens for enlarging - the image stays in focus for the whole session printing, but if I switch to the 80mm and printing, it goes out of focus very quickly, have to check it every time I make a print, can even go out of focus while printing - especially troublesome for large prints with long exposure times. Has anyone had this before?
Yes, I use the focus lock alright, have it tightened to max, but the 80mm still constantly migrates out of focus, but never the 150mm, tis strange alright.
Sometimes it's not the focus that's shifting but the entire head on the column, I had this with a Durst M601 which was very slowly creeping up the column.
I use a De Vere 5108 - the column and controls are the same as your 504, I've never seen this problem but lock the head as well as the focus, the counter weight springs is very strong it may vary slightly depending on the positioning of the head, plus an 80mm lens is a touch lighter than a 150mm maybe enough to affect the balance.
If you don't have a glass carrier, one method is to pre-heat the negative until it no longer shifts or pops. Then keep the light on, and put the lenscap on the enlarging lens. Put the paper on the easel and quickly, but without bumping the enlarger, turn off the light, set the timer and remove the lens cap.
If you have a red filter, you can slip that over the lens to insert the paper (after the negative is heated) and swing it out of the way to time the exposure.
Cheers for that Ic-racer, actually printing in the darkroom at the moment, will try that in a minute. And Ian, I think I know now the head lock, is that the dial opposite the focus lock at the baseboard level? I have always both these locked hard, but the 80mm still shifts, bit of a mystery why the 150 mm stays in focus, but will definitely be looking at the glass method.
My 5108 is floor standing there's two knobs at the back of the baseboard that lock the focus and head height adjustments. They don't need to be locked just loose enough to allow movent. Looking at photos of the 504 bench model they are the flush with the baseboard at the back either side of the column.
Cheers Ian, I do tighten both of them as it is, so the focus is probably to do with the heat on the neg, or maybe alignment, but will contact odyssey, see if they have the glass. Thanks a million for all your advice and help! G
504 and Ilford Multigrade head is a great system, but depending how the head is attached to the top, (using the Ilford conversion plates which they supplied with each head depending on the enlarger), there's a possibility the head is not lying on the neg carrier straight. There are four white plastic screws on the back of the plate the MG head is screwed onto the enlarger chasis which can be adjusted to help alignment.
But biggest thing is to get glass. Seems the larger the neg, the better chance it stays in focus without glass carrier. If you have problems with an 80, expect it may be worse with a 50mm. I always use anti newton glass on top and the silver carrier (the top one usually), on the bottom. Usually no problem with negs drifting. Though if it's a really long exposure, say heavy dense 35mm neg via 50mm lens up to 20x24" will use plain glass bottom and anti newton on top. With rublylith mask cut to size to prevent flare.
Cheers Mike, definitely will be investing in the anti newton glass - have a laser alignment tool as well, going to try that to see if there are alignment issues as well. Thanks a million to everyone for the great advice!