Bronica gs1 Focus problem

Hello everyone,

i have a new bronica gs-1 and a lot of focus problems, using a tripod helped but still , some glitches i dont understand.

So, My 100mm F3.5 doesnt focus on infinity, is that a common thing ? problem ? where is the problem ?

i attached a photo, in my WLV it didnt focus on inifty , but here in the attached photo - it is focused.

thank you so much

With medium format SLRs, the two simplest focus failure points to verify are the screen and the backs. First check your focus screen: is it fully seated and correctly installed? (be sure it isn't inserted upside down: should be shiny side up). Is the screen a genuine OEM Bronica screen, or an aftermarket "upgrade"? Look for the Bronica trademark somewhere on the frame: if it doesn't have one, or its marked "Beattie" or "BriteScreen", its probably a third party screen replacement. These alternate screens were once popular for improving brightness over the stock screen, but they have a tendency to be off-spec enough to mess with apparent infinity focus accuracy.

If the screen is OK, look at the film magazine. Do you have just the one magazine? If so, check that any screws on the mounting face that attaches to the camera are not protruding: screw them down flat. Make sure the back is fully latching onto the camera, with no gaps on the four sides. Check that you're loading the film insert properly. If you have more than one back, see if you have the same issue on both: if yes, the problem is likely in the camera body. If it only happens with one of the backs, the problem is that back.

Occasionally, infinity focus problems are due to a misaligned mirror stop position or the mirror being loose in its carrier. These issues would usually need attention from a professional repair tech: DIY is possible but tricky.

It isn't quite clear from your question whether the problem is consistently localized to the viewfinder: if you focus the lens to its infinity hard stop, do your photos of infinity subjects consistently come out sharp on the actual film even tho the viewfinder seems soft? If yes, the problem is almost certainly in the body mirror geometry or the screen.

With medium format SLRs, the two simplest focus failure points to verify are the screen and the backs. First check your focus screen: is it fully seated and correctly installed? (be sure it isn't inserted upside down: should be shiny side up). Is the screen a genuine OEM Bronica screen, or an aftermarket "upgrade"? Look for the Bronica trademark somewhere on the frame: if it doesn't have one, or its marked "Beattie" or "BriteScreen", its probably a third party screen replacement. These alternate screens were once popular for improving brightness over the stock screen, but they have a tendency to be off-spec enough to mess with apparent infinity focus accuracy.

 

If the screen is OK, look at the film magazine. Do you have just the one magazine? If so, check that any screws on the mounting face that attaches to the camera are not protruding: screw them down flat. Make sure the back is fully latching onto the camera, with no gaps on the four sides. Check that you're loading the film insert properly. If you have more than one back, see if you have the same issue on both: if yes, the problem is likely in the camera body. If it only happens with one of the backs, the problem is that back.

 

Occasionally, infinity focus problems are due to a misaligned mirror stop position or the mirror being loose in its carrier. These issues would usually need attention from a professional repair tech: DIY is possible but tricky.

 

It isn't quite clear from your question whether the problem is consistently localized to the viewfinder: if you focus the lens to its infinity hard stop, do your photos of infinity subjects consistently come out sharp on the actual film even tho the viewfinder seems soft? If yes, the problem is almost certainly in the body mirror geometry or the screen.

Omg, you nailed it! i took off the WLF and the screen was off by a bit, i put back in its right place. checked the inifity focus - and WORKING!

thank you so much!!!

Fantastic! :) Isn't it the best feeling to discover a problem is just a tiny little thing like that? What a relief!

Enjoy the GS1, and post more pics when you get a chance! It wasn't as popular back in its day as the smaller Bronica ETR and SQ systems, so there aren't nearly as many GS1 photos available on websites. Nifty 6x7 system idea, unfortunately it didn't catch on quite as well as Bronica had hoped (Mamiya RB/RZ was too entrenched by then). The handy winder grip & smaller AE prism was unique for the format.

Fantastic! :) isn't it the best feeling to discover a problem is just a tiny little thing like that? What a relief!

 

Enjoy the GS1, and post more pics when you get a chance! Its a fairly uncommon but very nice 6x7 film system.

Yes, i totally agree, i was already checking for a new back,

where do you usually post photos around here ?

where do you usually post photos around here ?

Several places: there's an "Images" subforum, multiple image-oriented threads in "Practice & Techniques" subforums, and you can also just start an independent thread with the topic "Bronica GS1 Nightscape Photos", etc.

BTW, really like your pic of the night time bicyclist on the bridge!