I've often wondered about the Pentax 6x7 or 67 camera. Looking at wikipedia I see the 6x7 is battery dependent. To what extent is this true? Can you run the camera without a battery? I'm assuming if you have to use a battery, are the required battery still available or what are folks using for a substitute? Also regarding lenses. What would be 35mm and 50mm equivalent.
Lets say I decided to buy one and the seller says it's in "working condition", are there light seals to replace? What are some questions to ask to make sure I'm actually getting a working condition camera?
Batteries are the common PX28 variety for the original Pentax 6X7 and the recommended subsequent version with the mirror lock-up feature (MLU). The later Pentax 6X7 II uses a different battery and different finders than the earlier models, but accepts the same lenses. The battery powers both the shutter and the meter in the prism finder, if that's the specific finder attached to it. These are very durable cameras. But sticky or failing seals or gaskets can be a problem on older units. These seals are inexpensive but messy to replace. It's better to buy a camera and prism finder without that issue - specifically ask before purchasing.
There are no 70 or 100 mm lenses. There is a choice between 105/2.4 and 90/2.8 for a "normal" perspective. And there are two versions of 75mm wide : the regular one is 75/4.5 - a bit dim to focus without an accessory magnifier (which they make), and not ideal for handheld shots, but optically superb (one of my favorite P67 lenses); these can be found at bargain pricing these days. And then there's the rarer 75/2.8, which you'll be unable to order because you will have already died of a heart attack if you noticed the asking prices.
There are also still wider lenses to choose from if needed, plus a large selection of excellent telephotos. It's a very versatile system; but you'll soon realize just how much heavier it is than an equivalent 35mm system. Hope you have a good tripod.
You will not regret the P67. Set up some time and funds for a CLA if it's the older 6x7 unit. It will be worth it. As others have stated, the optics, even low cost P67 optics, are stellar, well-constructed and deliver. If you check out the service manual, towards the end, you'll see the various improvements listed with the last iteration of the P67 MLU. Enjoy! Edit: file too large to post, but can be found easily with a search.
Oh yeah, but that's a later specialty lens and rather uncommon. Most macros were longer. But I just used an extension tube on the 105, and only for flat copystand work; 4X5 proved far more useful in the field for closeups.
The Pentax 67II uses 2 of the CR123 batteries. They are very commonly available as they are used in many different types of equipment. Yes, you need the batteries to operate the camera.
Get Pentax 67-ii if you have the budget. You will not regret it! P67-ii has become a highly sought of camera these days. I got mine in 2002 right when Pentax was about to halt production. I have since picked up almost all focal lengths of its lenses. All the shots I got were nothing short of being razor sharp and beautiful. I use a pair of rechargeable LiFePo4 CR123a (3.2V) batteries. One charge lasts me a year. It is quite a joy shooting a 220 roll and getting 21 frames of images. There are 2 Pentax 67 lenses that have built-in shutter in them (80mm and 165mm) that allows you for studio work using electronic flashes syncing at up to 1/500th of a second shutter speed. I love these two lenses out door more than other lenses. They render absolutely most beautiful images. These days the P67-ii is still not cheap but almost all lenses are very affordable. It is a fun building up a system with all those affordable lenses.