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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Promaster Infinity 7x32 review (1 Viewer)

Kevin Purcell

Well-known member
The Promaster Infinity 7x32 is an older, now discontinued, bin. You can get them at Helix Camera for $40 + $10 s/h. They were originally sold for $100 to $140 or so I think. Promaster's model number is 8654.



Field of View - 389' @ 1000 Yards
Power - 7X
Eye Relief - 18mm
Prism - Silver Coated BAK-4 Porro
Weight - 20.3 oz.
Coating - Fully Broadband Multicoated
Minimum Focus Distance - 13'
Waterproof, Nitrogen filled
Includes deluxe case

They aren't phase corrected but the optics are quite good. They are quite long (objective to ocular) for a x32 bin which is interesting as it means the objective is running at a higher f number than usual (not by a lot but I think it helps). I get the feeling the optical designer was trying to do a good job but the implementation let him down.

The extra 1" in length makes their grip much easier than say the "small and compact" 8x32 bin. The grip is closer in feel to an 8x42 with my left hand wrapping around the barrel towards the objectives and the right hand on the focuser.

The rest of the mechanical construction is a bit iffy. The rubber armor is silicon rubber based (I think). The monomer is bitter to taste when you get it on your fingers: not a good sign. The armor is bluish-gray and marks in an odd lighter color that wipes off (I think it's just sloughing off skin cells). It has ragged edges and mold lines - not great finishing. The rainguard and the objective covers (non-tethered but made like a rainguard) are made out of the same stuff. Still they all work OK and after a wipe down with isopropanol they seem to have little problems (except for that monomer!).

After using them the first time I found my vision got worse! Then I noticed I had two greasy rings on my eyeglasses. At first I thought it might be plasticizer from the eyecups but it turned out to be over-vigorous application of lubricant to the eyecups that had leaked to the lip of the eyecup. A cleanup with tissue and isopropanol fixed that and removed the surplus lube. No more problems. But the QA should have caught that.

The strap is rather cheap one piece nylon strap (and short but usable beck strap). Not stretchy but adjustable. But it works OK.

The "deluxe case" is classic silly over featured design. Should we have a zip, Fastex or Velcro closure? Why not all three! The bin compartment has a zip closure with rather crappy zippers: one of the pulls broke in two when opening it for the first time. There is also a mesh divider in there that makes it more difficult to grasp the bin and pull it out. The rather useless front compartment has both Fastex and Velcro closures (WTF!). It has a business card holder (nice touch for name and address) and another couple of zipped compartments that aren't big enough for much of anything. There is an external zipped pocket on the back. It's not so much design as throwing features at the case even if they're useless. There are a few zipped pockets but most are not useful for holding much. A simpler case would have been better. The case has a belt mount loop (that works nicely) and shoulder strap with swivel clips.

I compared the view to some other lower end bins I have. It optically beats the Winchester 8x32 a similar era Chinese bin that is mechanically better made but has poorer coatings and a little aberration in one barrel. But the Promaster is worse than a Diamondback or even more so Pentax DCF WP (my very good $50 bin!). Those are both sharper, more contrasty, better color saturation.

I found them OK for sharpness even given their missing PC. They do show classic diffraction spikes from bright "star-like" objects (typical of missing PC and diffraction across the roof edge) so the roof prism edge is not as sharp as it could be. But the Promaster 7x32 is one of the best non-PC I've looked through (not seen the older Alpha bins).

They are pleasantly neutral in color. Brightness is about average for 32mm bins I've tried even given their silver prism coating.

FOV is good at 7.5 degrees (not verified the angular size but it seems about right). AFOV should be 52 degrees (not big but not too small either).

They were consistent barrel to barrel too. One problem people have with "no PC == bad" judgement is they've seen too many badly made Chinese bins in the past decade that didn't have PC but also had a bunch of other issues (one good barrel the other bad, aberration of various forms, optical tilt, optical pinching). There were fine non-PC roofs without PC before the Chinese start making them but the Chinese were making mistakes in other areas. For most of the "decent" and better bins from China this is no longer a problem.

They have enough eye relief to just about see the whole 7.5 degree field with eyeglasses on. They could do even better if the eyecups weren't as deep as they are. I feel they throw away a couple of mm in the depth of the eyecup that they need not have done. The eyecups don't feel too comfortable when used without glasses (I just did that for a test). They leak light too at the lower edges (which is not good ... see below).

The optical coatings are quite good for a inexpensive binocular: the whole bin seems fully multicoated as specified and they work too.

So a non-phase corrected roof they're OK. For a $40 roof they're rather good e.g. think of the crappy 8x25 you could get for $40. But i wouldn't have paid full price for these.

Where they really fall down is stray light and that seems to be due to lack of attention to details in the optical implementation.

I think they were made by an OEM who hadn't been doing roof for too long. I suspect you can get away with somethings in porros (because they're not a straight tube) that you can't in roofs.

So the focusing lens (which is big and very close to the objective) is carried on a tube attached to a plate that also seems to be intended as a baffle but it doesn't go to the edge of the barrel ... there's a few millimeters gap (you can see it with a flashlight).

That might not be an issue but the interior of the barrel is polycrystalline (either anodized aluminium or the tube coating, I think it's the former). All of it is dark but some of the crystals are orientated so they are very reflective down the tube so there is some light scatter in the tube. I've seen worse so this is not a big problem.

Worse are the glints from just outside the objective (there is a sawtooth grooved surface to reduce reflection but the blackened surface again is somewhat crystalline and rather reflective. The sun catching this gives a starburst glint (as opposed to veiling glare across the objective. It would look cool in a driving game but it's a pain in a bin. The same problem occurs on the metal ring of the ocular mount. It's blackened (or pained) but rather crystalline so light getting in from the side glints with a starburst at the ocular. These are probably fixable with some anti-reflective paint but it's a shame they didn't just specify a matte black coating for these metal parts originally.

I've still got mine as a around the apartment, loaner or perhaps a car bin. It's optically better than another Winchester loaner which is better mechanically built but has barrel to barrel consistancy problems (aberration) plus scatter from the poorer AR coatings which flares (like a diffuse halo) around bright objects). That was a second hand $40 bin that was intended for the same $100 to $140 price point with a serial number that indicates a 2005 build year (and perhaps a similar design year 2004 or 2003 or so).

It brings the birds (or the animals) closer which is what a bin is supposed to do but I don't think I'd want to use it all day in a sunny enviroment. In overcast the glints are not obvious and it's easy to use. It all depends what you want to compare it to: it's better than any other $40 bins I can think of.

But it's not a Promaster ELX ED 7x32, that's for sure!

I'm curious what the intermediate generation of ELX 32mm bins are like. ;)
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With 7x, if I don't get 500 ft of fov, I feel like I did not get my money's worth. I always want more of something.
Tero, Can you name a 7x roof prism bin with 500 foot @ 1000 yards FOV?

The best I can think of is the Zeiss 7x42 Dialyt or current FL which is 450 ft./1000 yds.

I think the only ones I can think of are Russian/Chinese 7x30 military porros that get in that area.

I find a 7.5 degree FOV is fine for most usages.

The advantage of the 7x are the typical advantages of lower magnification: a bigger exit pupil (4.5mm in this case) gives a relaxed view and reduced shake.

The roof format is easy to hold in this slightly longer size size. I find it fits my hands very nicely.

This good fit seems to be related to the 5" height of this bin (and others like the Zeiss Conquest 8x30 at 5.6" tall and Swift Eaglet 7x35) as compared to the about 4" (and a bit) height of most of the 32mm (and 28mm) bins which I find a bit less comfortable to hold. The 5" long bins seem to accommodate both of my (largish) hands in two non-overlapping and natural feeling positions.

It's a shame about the stray light problems ;)
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No, I do not know of one, but I always set my roofer requirements by the best that the porros can do. ;)

I find the standard 8x32 pairs easiest to hold, so a 7x32 should be roughly the same size we are used to. Maybe a 7.5x32 and a 9.5x32 for my wish list. Or if I could "titrate" to my personal best, maybe 9.5x36.
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