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Monday, February 28, 2011

Letus Carbon Fiber Hawk LCD Loupe review

FINALLY ! I have to admit this review has been delayed due to a number of things from simply being busy at work to some personal events I had to deal with. Well here it is, and I'm going to talk about some things you won't see mentioned in another reviews of this product. I know that because I've read most of them. The fact is I did buy this product based on those reviews and in some places I'll agree, and in others, well I'll get to them in a bit.


Letus CF Hawk LCD Viewfinder loupe

Shot on my iphone... 

Unlike some reviews which are based on very limited use on the reviewer's part, I've had the unit for several months, and done quite a bit of shooting with it. I think that gives me a much better perspective on the good and bad points of this product.
In the same class as the Letus Hawk is the Zacuto Z finder. The Z finder has been the product to compare everyone else to. In terms of price  ( $375 on Letus website ) the Hawk is just a couple dollars cheaper then the Z finder, which means neither is cheap. 
The Hawk is available in the sleek sexy carbon fiber version, or cast aluminum. I went for the CF version because I liked its looks better, and CF materials are better to handle and work with when you shoot in the cold.


First and foremost is that the quality of the optics is great. The 3 lens optical assembly is sharp, and you can see pixels. Now there are some other loupes out there that make like seeing pixels is some how bad. The truth is they simply aren't as sharp. Its no picnic trying to judge focus off the back the of the camera's LCD with or without a loupe but having a soft loupe doesn't help. At the very least, the loupe should be sharp enough to let you see the screen as clearly as possible even if that does mean being able to see the pixels. If you can't, how else can you really tell when you got focus as sharp as possible ? you can't. 
The optics are setup with a 2.75X magnification. It seems ok, to perhaps slightly large in my view with experience on real broadcast cameras. I found I did need to look side to side sometimes to really pay attention to what was going on. 
Now lets talk about some problems of the optics. First is that eye point of the lens assembly is a bit high, at least for me. By that I mean that I found my best focus on the screen was keeping my eye 1/2" to 1" away from what would be considered the proper up close position where you were in contact with the eyecup.
 My vision for middle range to distance is normal. When you place your eye to the VF, your eyes should be focused for infinity for best fit and focus. This isn't just a textbook ideal, its a very practical requirement when shooting hand held when you'll want a loupe the most. If you are shooting anything fast moving you always shoot with both eyes open to see whats going on. This lets you be able to react to what is going on, especially if that means getting out of the away of some one or some thing ! If I focused my eyes a bit closer I could get good focus. Likewise, if I pulled the entire hood assembly back a 1/2 inch that also worked ok. Letus does not have a spacer kit like Zacuto does, so there isn't any simple way to mount the hood further back, but I have an idea on how to make one. 
I found that the CF lens hood cut off the sides of the viewfinder on my 60D. No amount of messing around would get me complete side to side coverage with the hood mounted as close as it could be to the screen. However, if I could mount the hood back a bit, then it would cover the entire area. I'd estimate that I lost about 3% of the left and right side. Its enough to not be able to see the last bar on the battery meter.  Ok, so I checked their website today : they now offer an aluminum 3:2 model for the tXi and 60D series cameras. When I bought mine this wasn't an option. To their credit, the hood housing is $99. You can unscrew the optics an move it over to the hood you need. Now that is cool to accommodate folks who update their camera bodies. 
Another problem with the eyepiece is that will will fog up outside when used in cold environments if you get your eye too close. This can make shooting miserable, and you run the risk of getting enough fog on the glass to have it freeze on really cold days. So there are no antifog coatings on the glass, nor is there any ventilation in the eyecup to let moisture from your eye out. It might be interesting to try some antifog treatments to see if any of them improve this. Having shot on numerous big video cameras, this is a common problem, but it seems compounded with the Hawk because there is little physical air volume to disperse or reduce moisture in the air from your eye.


I'm not going to beat them up to much on this one as they are aware of it : the eyecup is just too small. If all you ever used was a consumer camera, its huge, its great. If you have every used a pro video camera you'll know its about half the size of a proper eye cup.


This all brings me to what is clearly the weakest part of the product, the mount that holds hood on. V1 of the product had used thumbscrews which was quickly replaced by the V2 quick release mount. The mount does work but it really leaves a lot to be desired. First its simply loose. The hood has wiggle room in the mount and no way to adjust it out. This probably wouldn't be so bad if the mount let the hood get snug onto the LCD screen. Well no matter what I did to adjust the mount, I could not get the hood to sit snug and flat against the screen. Part of the problem is that when you tighten down on the allen screws, it causes the parts to move a bit. Some small washers would help here. 
The allen head bolts used in the mounts just plain old junk. They are low quality soft steel parts. Even without much use, one of the allen heads has rounded out on me. They don't send you any spares. These bolts should be upgraded to hardened stainless steel parts for durability since they are so small. However, before you run off to the hardware store to find some, keep in mind the FIRST Hawk VF I had in fact had one stripped out screw hole from the factory. Unless Letus is having quality hardened inserts used on the hood, using hard grade bolts could strip this tiny holes out. The only option would be to drill and tape the holes for the next bolt size up, or replace the unit. 
So The first Hawk I had was replaced a couple of days after I got it due to the stripped hole.
My solution to the play has been to run some 1/4" dark gray foam weather stripping around the edge of the unit. The soft foam blacks the light out while taking up the space between the screen and the hood very nicely.  It also gets rid of the play from the mount. The hood does have a rubber bumper on it, but on 3 of the units I've had, none of them have been glued on as they are supposed to be. This makes it super easy to loose the piece, and weather stripping be your fix unless Letus sends you a replacement. You could probably glue it on with ACC / Crazy Glue or epoxy.
Now I bet you just said, " what do you mean I've had 3 units ? " 
Ok here is the story. The first Hawk I got had a stripped out mounting hole on the hood. Letus replaced it promptly. The second unit had good bolt holes, and it also had the quick release that the first unit was supposed to ship with. However after several weeks an odd blemish developed inside the lens assembly. It was perhaps some fungus or mold that grew on what I'd guess to be a tiny partial finger print. The blemish was maybe 1/8" or so round and visible when looking through the unit. Letus replaced that one too, which is how I got to number 3. Their factory seems to have some quality control problems I hope are fixed by now.
So do you think I'm done talking about the hood mount ? no ! There's more unfortunately.
Letus Bad Alignment
Another problem with the mount's quick release is that it extends _below_ the bottom of the Hawk base plate. The base plate itself is a nicely machined hunk of aluminum which keeps the plate's mounting hole on center with the camera's mounting hole. This is critical for use with matte boxes that expect the lens to be centered on the rails. 
Now back to the quick release mount. If you have a base plate thats around the same size of the Hawk base plate you are fine. If you are using something like a long sliding base like I have, which extends several inches behind the camera you now have a clearance problem. At best you can stick the Hawk's quick release mount in about 1/3 of the way before it will jam against the base plate. The way the entire thing is designed, you'd have to add 1/16" to 1/8" of shim _underneath_ the hawk base plate to push it up higher from the rails base plate to get the quick release mount to go in square. There is nothing you can do to file the quick release mount down that wouldn't seriously compromise its structure. The fix on Letus's end is to make the base plate thicker so it clears properly. 
I might consider adding some rubber or make a shim for the baseplate myself, but then that means adjusting the height of all the long lens supports I have on my rails. Thats a tedious pain with my setup I'd prefer to skip having done it twice already. If you have an easy to height adjust camera mount, this probably isn't a big deal.
Speaking of the baseplate for the Hawk, it has yet another problem. While its well made, it has no lip or curve on the top of it, the part that contacts the camera to prevent the camera from twisting. A lot of new plates which go onto the camera now have this critical feature. Without it, you'll find that every several uses you'll need to tighten the Hawk baseplate screw. Its a simple slotted screw that requires a screwdriver or thin coin to tighten properly. It would be great if they went to a tool-less  design. This isn't a problem thats just Letus's, but just about every camera base plate has this same problem. If you don't use big lenses and move around a lot, you'll probably be ok and not notice this.


Letus needs to overhaul its base plate design. For $375 I have really mixed feelings about this product. The optics themselves are great and deliver a sharp image. The flaw of this product its the baseplate that makes using it with certain configurations far from ideal, and really not something I'm comfortable with giving a thumbs up on for the price. I should not have to be using weather stripping to fix the mount problems. On the other hand, if you find the Z finder or other loupe's soft, the Hawk may well be worth a look if you are using a small cameras base plate and won't run into the problems that I did.